DEV Community: Jem

Join the Hacktoberfest Open-Source AI Challenge: Side Hustle! $2,550 in Prizes Across 18 Winners.

Jem — Mon, 12 Oct 2026 19:01:08 +0000

Week 2 of our five Hacktoberfest DEV Challenges starts today! Running through October 18, the Hacktoberfest Open-Source AI Challenge: Week 2 gives you a full week to build.

This year's Hacktoberfest is all about building brand-new projects with open-source AI and open-weight models. Here's everything you need to know about Hacktoberfest 2026.

Missed Week 1: Touch Grass? No problem. Every challenge is a fresh start, so you're competing on the same footing as everyone else.

This week, we'll select one overall winner and a winner in each of our 17 partner categories. See all five challenges and current partner categories on the HF26 DEV Challenge Hub.

Let's get to it!

This week's theme: Side Hustle

Build something with open-weight models or open-source AI that someone would actually pay for.

That can mean running an open-weight model, building on an open-source agent harness or framework, running inference locally, or all three. Whatever you pick, the open pieces should be what makes your project work.

Think small, specific, and useful. The best builds here solve a real problem for a real person, whether that's a freelancer, a small business owner, a niche hobby community, or your friend who keeps complaining about the same tedious task. A few ideas to get you going:

An invoice and receipt sorter for freelancers that runs locally, so client data never leaves their laptop
A listing writer for Etsy or eBay sellers that turns a few product photos into a polished description
A menu translator for a local restaurant that handles their specific dishes better than a generic tool

In your post, tell us why open innovation matters for what you built. Does running your own model keep costs low enough that the business actually works? Keep your customers' data private? Let you fine-tune for a niche that a general-purpose API handles poorly? Avoid getting locked into someone else's pricing? Tell us where your open-based approach worked better than a closed one.

Bonus points if you land your first user. Get it in front of someone, let them use it, and tell us how it went. Did they pay? Would they? What did they ask for next?

Side Hustle Submission Template

Prize Categories

Alongside our overall winner, we have 17 prize categories for projects that use a specific partner's technology. You don't need to use any of these to win the overall prize, but if you've been curious about any of this tech, this is a great excuse to give one a try. Full descriptions are on the hub.

Featured categories:

Partner categories:

Pro Tip: Partner category winners come from a smaller pool of submissions, so your odds are meaningfully higher.

Note: One project can enter every category it genuinely uses, but you can only win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.

Free credits: several partners are giving participants credits and promo codes, including Tinker, Render, and Backboard. Claim yours at hacktoberfest.com/my.

A huge thank you to our partners for making these prizes possible!

Judging Criteria

This is DEV, so your write-up matters most.

Writing Quality (weighted most heavily): Is the post clear and engaging? Does it explain what you built, who it's for, and why open innovation matters?
Relevance to the Prompt and Theme: Is open-source AI or open-weight models at the core of the project? Is it something someone would actually pay for?
Creativity: Is it an original idea, or a fresh take on a familiar problem?
Technical Execution: Does it work, and is it well built?
Use of Partner Technology (optional): If you're entering a partner category, does the project use that technology in a meaningful way?

Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.

Prizes

Overall winner (1): $250 USD, a DEV++ membership, and an exclusive DEV badge
Featured category winners (6): $200 USD and an exclusive DEV badge each
Partner category winners (11): $100 USD and an exclusive DEV badge each

All participants with a valid submission will receive a completion badge.

How To Participate

Publish a post on DEV using the submission template below. Tell us what you built and who would pay for it, show us a demo, and explain why open innovation matters for what you built. If you landed your first user, tell us about it!

Side Hustle Submission Template

Please review our judging criteria, rules, guidelines, and FAQ page before submitting so you understand our participation guidelines and official contest rules, such as eligibility requirements.

Need Help?

New to Hacktoberfest this year? Start with Everything You Need To Know About Hacktoberfest 2026.
Come hang out and ask questions in the MLH Discord.
The challenge page has resources from our partners to help you get started.

Important Dates

October 12: Hacktoberfest Open-Source AI Challenge: Week 2 begins!
October 18: Submissions due at 11:59 PM PDT
Week of October 19: Winners announced

Looking Ahead

Week 3 launches Monday, October 19 with a brand-new theme. Be sure to register so you don't miss the announcement.

Signed Up Sign Up Sign Up

Questions about the challenge? Drop them in the comments below.

Happy Hacktoberfest, and good luck!

Congrats to the Hacktoberfest Weekend Challenge: Build for a Friend Winners!

Jem — Fri, 09 Oct 2026 19:32:27 +0000

We are so excited to announce the winners of the Hacktoberfest Weekend Challenge: Build for a Friend, the first of five challenges kicking off this year's Hacktoberfest!

This was our most participated-in challenge to date, nearly tripling our previous record for submissions. We asked you to build something with open-source AI at its core for one real person in your life, and you showed up for your parents, grandparents, siblings, classmates, roommates, and friends. Many of you told us how the person you built for reacted, and those stories made judging both a joy and a challenge.

Thank you to everyone who participated. Your projects show exactly why open models matter: private data stays at home, tools run without a credit card, and builders get to shape AI around the people they care about.

Now, let's celebrate our winners!

🎉 Congratulations To…

Overall Winner

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

ADK BBX

Oct 4

Phone calls are the boss fight of living in Japan. 🗼

#devchallenge #weekendchallenge #hf26challenge #ai

13 min read

Featured Prize Category Winners

Best Use of Arduino

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Abhinav krishna N

Oct 5

Project JARVIS: The Offline AI Lab Assistant

#devchallenge #weekendchallenge #hf26challenge

10 min read

Best Use of DigitalOcean

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Alex Georgiev

Oct 2

The BMW manual was off-limits, so I built my friend something better

#devchallenge #weekendchallenge #hf26challenge #ai

10 min read

Best Use of Gemma

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Uptime Architect

Oct 4

Gemma 4 reads my parent's mail at home: 39 test letters, 9 of them real, and one calm wrong answer I engineered out

#devchallenge #weekendchallenge #hf26challenge #gemma

11 min read

Best Use of Render

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Vicente G. Reyes

Oct 3

Tala: Free Audio-to-Text for My Designer Friend (No Signup, No Credit Card)

#devchallenge #weekendchallenge #hf26challenge #ai

7 min read

Best Use of TabPFN

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Robert Moore

Oct 4

My mate wants a sub-5 70.3. Before recommending one, I made an open model predict 79 of my old race legs.

#devchallenge #weekendchallenge #hf26challenge #ai

10 min read

Best Use of Tinker

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Muaaz Shaikh

Oct 4

Rakshak: I built my parents a scam-checker that never leaves the house

#devchallenge #weekendchallenge #hf26challenge

9 min read

Prize Category Winners

Best Use of Backboard

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Yash Kumar

Oct 2

Kharcha: a 4B model that reads Indian bank SMS so the money stays on your laptop

#devchallenge #weekendchallenge #hf26challenge

7 min read

Best Use of ElevenLabs

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Rahul Kumar

Oct 5

Padh Ke Batao: an AI that reads my grandfather's documents to him, on a laptop with no GPU

#devchallenge #weekendchallenge #hf26challenge #ai

7 min read

Best Use of Entire

Abdul Wasih

Oct 5

Viva: a mock interview that knows which parts of your project an AI wrote

#showdev #devchallenge #weekendchallenge #hf26challenge

4 min read

Best Use of GitHub Copilot

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Dosunmu Hassan

Oct 4

I built a panic button that doesn't tell me anything

#devchallenge #weekendchallenge #hf26challenge

9 min read

Best Use of Mastra

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Bipul Chamoli

Oct 2

Prep Buddy: an AI interview coach for my classmate that runs on his laptop with the Wi-Fi off

#devchallenge #weekendchallenge #hf26challenge

8 min read

Best Use of MongoDB Atlas

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Elev 💥

Oct 4

I turned my sister in law's voice notes into a cookbook that answers in her voice

#devchallenge #weekendchallenge #hf26challenge #opensource

8 min read

Best Use of Sentry Agent Tracing

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Arqam Waheed

Oct 5

"If it's not in front of me, it's gone": I fine-tuned a 4B model for my friend with ADHD

#devchallenge #weekendchallenge #hf26challenge #ai

12 min read

Best Use of SerpApi

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Muhammad Murtuza Hussain

Oct 2

Pīzhù 批注: a writing tutor that never rewrites your essay, built for my friend Joy (Gemma 4)

#devchallenge #weekendchallenge #hf26challenge #hacktoberfest

10 min read

Best Use of Temporal

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Prateek Rai

Oct 3

PaidYet: for the friend who says “kal bhej dunga”

#devchallenge #weekendchallenge #hf26challenge #opensource

9 min read

Best Use of Tiger Data

Hacktoberfest Weekend Challenge: Build for a Friend Submission 🤝

Priyanshu Jha

Oct 5

My friend runs her supplements shop from WhatsApp voice notes, so I built her a shop helper

#devchallenge #weekendchallenge #hf26challenge #ai

7 min read

Prizes

Our overall winner will receive:

$250 USD
DEV++ Membership
Exclusive DEV badge

Our featured prize category winners will each receive:

$200 USD
Exclusive DEV badge

Our prize category winners will each receive:

$100 USD
Exclusive DEV badge

All participants with a valid submission will receive a completion badge.

A huge thank you to our partners, Render, Prior Labs, Thinking Machines, Arduino, DigitalOcean, Google, Backboard, ElevenLabs, Entire, GitHub, Mastra, MongoDB, SerpApi, Sentry, Temporal, and Tiger Data, for making these prizes possible!

What's Next?

Hacktoberfest is just getting started! We're launching a new challenge every week this month. Each challenge is a fresh start, so it's not too late to jump in. Week 1 is happening now:

Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass Submission 🌿

Jem for The DEV Team

Oct 5

Join the Hacktoberfest Open-Source AI Challenge: Touch Grass! $2,450 in Prizes Across 17 Winners.

#devchallenge #hf26challenge #hacktoberfest #softwaredevelopment

258

7 min read

Week 2 launches Monday, October 12, with a brand-new theme. Register for the upcoming challenges to be notified as details drop:

The Hacktoberfest Open-Source AI Challenge: Week 2 runs October 12 to October 18. This week's theme is Side Hustle: build something with open-weight models or open-source AI that someone would actually pay for. $2,550 in prizes across 18 winners. This year's Hacktoberfest is all about building brand-new projects with open-source AI and open-weight models. Every week brings a new theme, and every challenge is a fresh start, so you're competing on the same footing as everyone else.

Signed Up Sign Up Sign Up

Happy Hacktoberfest 💜

Congrats to Our First MLH x DEV Writing Challenge Winner!

Jem — Fri, 09 Oct 2026 18:56:35 +0000

We just wrapped the very first month of the MLH x DEV Writing Challenge, our new way of celebrating MLH hackers who take the time to document what they built. We loved reading through the submissions, and we're excited to kick things off by shining a spotlight on our favorite one.

Your hackathon may end after the weekend, but as this month's pick proves, your project story is just getting started.

Let's get to it!

🎉 Congratulations To…

This Month's Winner

Pritam Patra

Sep 22

OmniML: We Built an AutoML System That Refuses to Be a Black Box

#mlhacks #devchallenge #hackathon #ai

7 min read

@pritam_patra_429a25dedae6 built OmniML, a tool that helps build AI models and explains what's happening under the hood. Instead of a black box that spits out a finished model, OmniML checks in with you along the way, letting you weigh in on how the model is built, what data it's learning from, and how it's trained. It even explains its own decisions in plain terms and flags whether the result is fair and compliant, so you're never left guessing why it made the choices it did.

Prize

This month's winner will receive:

$100 USD

Just got back from a hackathon?

Don't let your project story end there. Publish your own submission using the official submission template for a chance to be featured next month.

What's Next?

Hacktoberfest is in full-swing and we're running a new challenge every week, each with a new theme. There's still time to enter this week's challenge:

Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass Submission 🌿

Jem for The DEV Team

Oct 5

Join the Hacktoberfest Open-Source AI Challenge: Touch Grass! $2,450 in Prizes Across 17 Winners.

#devchallenge #hf26challenge #hacktoberfest #softwaredevelopment

257

7 min read

Signed Up Sign Up Sign Up

See you next time!

Join the Hacktoberfest Open-Source AI Challenge: Touch Grass! $2,450 in Prizes Across 17 Winners.

Jem — Mon, 05 Oct 2026 18:03:31 +0000

Week 1 of our five Hacktoberfest DEV Challenges starts today! Running through October 11, the Hacktoberfest Open-Source AI Challenge: Week 1 gives you a full week to build.

This year's Hacktoberfest is all about building brand-new projects with open-source AI and open-weight models. Here's everything you need to know about Hacktoberfest 2026.

Missed the Hacktoberfest Weekend Challenge? No problem. Every challenge is a fresh start, so you're competing on the same footing as everyone else.

This week, we'll select one overall winner and a winner in each of our 16 partner categories. See all five challenges and every partner category on the HF26 DEV Challenge Hub.

Let's get to it!

This week's theme: Touch Grass

Build something with open-weight models or open-source AI that gets people off the screen and into the world.

Hiking, gardening, birding, run clubs, fall foliage: if it gets someone outside, it counts. The best builds here should make the screen the shortest part of the experience. A few ideas to get you going:

A bird call identifier that works on the trail with no signal
A garden planner that tells you what to plant this week based on your local frost dates
A run club route builder that finds the best fall foliage near you

In your post, tell us why open innovation matters for what you built. Does it run on a phone in the backcountry with no internet? Keep someone's location data off a server they don't control? Let you fine-tune, swap models, or change how your agent behaves? Cost nothing to run? Tell us where your open-based approach worked better than a closed one.

Bonus points if you take it outside, use it, and tell us how it went.

Touch Grass Submission Template

Prize Categories

Alongside our overall winner, we have 16 prize categories for projects that use a specific partner's technology. You don't need to use any of these to win the overall prize, but if you've been curious about any of this tech, this is a great excuse to give one a try. Full descriptions are on the hub.

Featured categories:

Partner categories:

Pro Tip: Partner category winners come from a smaller pool of submissions, so your odds are meaningfully higher.

Note: One project can enter every category it genuinely uses, but you can only win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.

Free credits: several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my.

A huge thank you to our partners for making these prizes possible!

Judging Criteria

This is DEV, so your write-up matters most.

Writing Quality (weighted most heavily): Is the post clear and engaging? Does it explain what you built, who it's for, and why open innovation matters?
Relevance to the Prompt and Theme: Is open-source AI or open-weight models at the core of the project? Does it get people off the screen and into the world?
Creativity: Is it an original idea, or a fresh take on a familiar problem?
Technical Execution: Does it work, and is it well built?
Use of Partner Technology (optional): If you're entering a partner category, does the project use that technology in a meaningful way?

Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.

Prizes

Overall winner (1): $250 USD, a DEV++ membership, and an exclusive DEV badge
Featured category winners (6): $200 USD and an exclusive DEV badge each
Partner category winners (10): $100 USD and an exclusive DEV badge each

All participants with a valid submission will receive a completion badge.

How To Participate

Publish a post on DEV using the submission template below. Tell us what you built and how it gets people outside, show us a demo, and explain why open innovation matters for what you built.

Touch Grass Submission Template

Please review our judging criteria, rules, guidelines, and FAQ page before submitting so you understand our participation guidelines and official contest rules, such as eligibility requirements.

Need Help?

New to Hacktoberfest this year? Start with Everything You Need To Know About Hacktoberfest 2026.
Come hang out and ask questions in the MLH Discord.
The challenge page has resources from our partners to help you get started.

Important Dates

October 5: Hacktoberfest Open-Source AI Challenge: Week 1 begins!
October 11: Submissions due at 11:59 PM PDT
Week of October 12: Winners announced

Week 2 launches Monday, October 12 with a brand-new theme. Follow #hf26challenge so you don't miss the reveal.

Questions about the challenge? Drop them in the comments below.

Happy Hacktoberfest, and good luck!

Join the Hacktoberfest Weekend Challenge: Build for a Friend! $2,450 in Prizes Across 17 Winners. Submissions Due October 5 at 6:59 AM UTC.

Jem — Fri, 02 Oct 2026 02:02:58 +0000

Winners Announced!

Record-breaking participation with open-source AI

Jem for The DEV Team

Oct 9

Congrats to the Hacktoberfest Weekend Challenge: Build for a Friend Winners!

#devchallenge #weekendchallenge #hf26challenge

4 min read

Hacktoberfest is here, and so is the first of our five Hacktoberfest DEV Challenges: a Weekend Challenge sized to fit into your weekend. We've set the timing so that wherever you are in the world, you'll have most of your Saturday and Sunday to build.

This year's Hacktoberfest is not about open source pull requests. There's no PR count to hit and no repos to hunt for. Instead, you build a brand-new project with open-source AI at its core, and write about it on DEV. Here's everything you need to know about Hacktoberfest 2026.

We'll select one overall winner and a winner in each of our 16 partner categories. See all five challenges and every partner category on the HF26 DEV Challenge Hub.

Let's get to it!

Our Prompt: Build for a Friend

Build something with open-source AI at its core that solves a real problem for a friend or someone you love.

Pick one real person and build something for them. It doesn't have to be big. It has to matter to them. A few ideas to get you going:

A meal planner that knows your roommate's allergies
A patient practice partner for a friend learning a new language
A tool that turns your grandpa's voice memos into a family recipe book

In your post, tell us why open innovation matters for what you built. Does it run on a laptop with no internet? Keep someone's data off a server they don't control? Let you fine-tune, swap models, or change how your agent behaves? Cost nothing to run? Tell us where your open-based approach worked better than a closed one.

Bonus points if you actually hand it over and tell us what they said.

Prize Categories

Featured categories:

Partner categories:

Pro Tip: Partner category winners come from a smaller pool of submissions, so your odds are meaningfully higher.

Note: One project can enter every category it genuinely uses, but you can win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.

Free credits: several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my.

A huge thank you to our partners for making these prizes possible!

Judging Criteria

This is DEV, so your write-up matters most.

Writing Quality (weighted most heavily): Is the post clear and engaging? Does it explain what you built, who it's for, and why open innovation matters?
Relevance to the Prompt and Theme: Is open-source AI at the core of the project? Does it fit this challenge's theme?
Creativity: Is it an original idea, or a fresh take on a familiar problem?
Technical Execution: Does it work, and is it well built?
Use of Partner Technology (optional): If you're entering a partner category, does the project use that technology in a meaningful way?

Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.

Prizes

Overall winner (1): $250 USD, a DEV++ membership, and an exclusive DEV badge
Featured category winners (6): $200 USD and an exclusive DEV badge each
Partner category winners (10): $100 USD and an exclusive DEV badge each

All participants with a valid submission will receive a completion badge.

How To Participate

Publish a post on DEV using the submission template below. Tell us what you built and who it's for, show us a demo, and explain why open innovation matters for what you built.

Submission Template

Please review our judging criteria, rules, guidelines, and FAQ page before submitting so you understand our participation guidelines and official contest rules, such as eligibility requirements.

Need Help?

New to Hacktoberfest this year? Start with Everything You Need To Know About Hacktoberfest 2026.
Come hang out and ask questions in the MLH Discord.
The challenge page has resources from our partners to help you get started.

Important Dates

Launch: October 2, 2026, 2:00 AM UTC
Submissions due: October 5, 2026, 6:59 AM UTC
Winners announced: week of October 5

Timezone	Launch	Submissions Due
PDT	Thu Oct 1, 7:00 PM	Sun Oct 4, 11:59 PM
EDT	Thu Oct 1, 10:00 PM	Mon Oct 5, 2:59 AM
GMT	Fri Oct 2, 2:00 AM	Mon Oct 5, 6:59 AM
CEST	Fri Oct 2, 4:00 AM	Mon Oct 5, 8:59 AM
IST	Fri Oct 2, 7:30 AM	Mon Oct 5, 12:29 PM
JST	Fri Oct 2, 11:00 AM	Mon Oct 5, 3:59 PM
AEST	Fri Oct 2, 12:00 PM	Mon Oct 5, 4:59 PM

Then a new challenge launches every Monday in October. Follow #hf26challenge so you don't miss a theme reveal.

Happy Hacktoberfest, and good luck!

Congrats to the DEV Weekend Challenge: Generosity Edition Winners!

Jem — Thu, 01 Oct 2026 21:44:54 +0000

We are excited to announce the winners of our DEV Weekend Challenge: Generosity Edition!

We asked you to build something in the spirit of generosity and left the interpretation wide open. Over one weekend you built grant radars that refuse to trust their own model, a hospital night shift where your starting money was left by the last player, and matchmakers that turn three boxes of storybooks into an actual plan.

Thank you to everyone who participated. Short challenges ask a lot in very little time, and it showed in the best way.

Now, let's celebrate our winners!

🎉 Congratulations To…

Overall Winner

DEV Weekend Challenge: Generosity Edition Submission 💜

Asuran

Sep 6

A charity does not close because its overhead was too high. I checked 328,186 tax returns.

#devchallenge #weekendchallenge

9 min read

@zkasuran built Keepalive, a tool that computes the sustainability of 579,178 US nonprofits straight from their own tax returns. The findings sugges the most common metric for choosing which charities to give to (how little they spend on fundraising) point not to efficiency but to a shorter life span. It's a project that reframed our idea of charity in a meaningful way.

Best Use of Snowflake

DEV Weekend Challenge: Generosity Edition Submission 💜

Emma Sofia

Sep 5

We Throw Away 1.3 Billion Tons of Food While Millions Starve. I Built FoodBridge with Snowflake to Stop It

#devchallenge #weekendchallenge #snowflake #webdev

6 min read

@emmasofia built FoodBridge, a food rescue grid that matches businesses with excess food with nearby shelters that need it, before the food spoils. Snowflake does real work here rather than sitting underneath as storage: window functions rank perishable batches by urgency, micro-partition clustering keeps dispatch queries fast on a volunteer driver's phone, and EPA WARM calculations turn every rescued pound into auditable carbon data.

Best Use of ElevenLabs

DEV Weekend Challenge: Generosity Edition Submission 💜

Sarvar Nadaf

Sep 7

ReachAloud: I built a multilingual voice tool that reads emergency alerts aloud for people who can't read the screen

#devchallenge #weekendchallenge #a11y #elevenlabs

5 min read

@sarvar_04 built ReachAloud, which turns written emergency alerts into spoken audio in any language for the people that text-only warnings leave behind. The voice is not a feature bolted on the side, it is the entire product, and the accessibility work impressed us: an emergency broadcast mode that serves low vision and low hearing at the same time, and a service worker that keeps the alerts playing when the network is gone.

Best Use of Google AI

DEV Weekend Challenge: Generosity Edition Submission 💜

ujja

Sep 5

I built PadForward because sometimes you just need a pad

#devchallenge #weekendchallenge #gemini #solana

11 min read

@ujja built PadForward, a community network for finding and donating menstrual products in public places, born from a very ordinary moment at a train station. Gemini is an agent here rather than a chatbot, calling validated application tools to route donations where the need score is highest, reading supply levels off a photo of a donation box, and degrading through on-device AI and plain heuristics when the network drops.

Best Use of Solana

DEV Weekend Challenge: Generosity Edition Submission 💜

Yash Kumar Saini

Sep 6

The receipt should come from the person who received it

#devchallenge #weekendchallenge #ai #rust

6 min read

@yashksaini built Cairn, which changes who issues the receipt for a donation. Funds unlock only when the recipient signs, and that signature carries the hash of a recording where they say what they received. The separation of authorization from testimony is a careful piece of design, and keeping one implementation of the hash function compiled for both chain and client is the sort of thing you only notice when it is missing.

Prizes

All five winners will receive:

$200 USD
DEV++ Membership
Exclusive DEV badge

All participants with a valid submission will receive a completion badge on their DEV profile.

What's Next?

Hacktoberfest is here, and we're launching events all month that center open-weight models and open-source AI.

Jem for The DEV Team

Oct 1

Hacktoberfest 2026 DEV Challenges: Five Challenges, One Prompt, a New Theme Every Week

#devchallenge #hf26challenge #hacktoberfest #opensource

6 min read

We're kicking the month off with the Hacktoberfest Weekend Challenge, launching later tonight. Register now so you don't miss the announcement:

The Hacktoberfest Weekend Challenge runs October 1 to October 5. Build something with open-source AI at its core that solves a real problem for a friend or someone you love. $2,450 in prizes across 17 winners. This is the first of five Hacktoberfest challenges on DEV. Every challenge uses the same prompt, with a new theme revealed each Monday in October.

Signed Up Sign Up Sign Up

We also have two other challenges happening right now:

Open-ended scope for custom model testing

Jem for The DEV Team

Sep 23

Join the Kaggle Benchmarking Challenge: $2,500 in Prizes for FIVE Winners!

#devchallenge #machinelearning #ai #kagglechallenge

204

4 min read

Jem for The DEV Team

Sep 18

Join the Sanity Challenge: $2,500 in prizes for FIVE winners!

#sanitychallenge #devchallenge #agents #webdev

268

8 min read

You can always find everything running at the moment on our challenges page.

Thanks again to everyone who built something generous with us 💜

Hacktoberfest 2026 DEV Challenges: Five Challenges, One Prompt, a New Theme Every Week

Jem — Thu, 01 Oct 2026 21:38:30 +0000

Hacktoberfest is here, and this October we're running five DEV Challenges back to back. Every challenge uses the same prompt. Every challenge gets its own theme, and each theme stays secret until the day it launches.

This year's Hacktoberfest is not about open source pull requests. There's no PR count to hit and no repos to hunt for. Instead, you build a brand-new project with open-source AI at its core, and write about it on DEV. Here's everything you need to know about Hacktoberfest 2026.

First up is our Hacktoberfest Weekend Challenge, launching in just a few hours. Then a new challenge launches every Monday in October.

How It Works

Five challenges: a weekend challenge to start, then a new one every Monday in October.
One prompt: the same prompt for all five, so you always know what we're looking for.
A new theme each time: the theme gives each challenge its own flavor. We reveal it the day the challenge launches.
One submission per challenge: that's up to five in October. Each submission is automatically in the running for the overall prize and every partner category it qualifies for. You can win once per challenge.
New projects, not pull requests: each submission is a new project built during that challenge's window. Pull requests to existing projects don't count this year.

Joining late? No problem. Every challenge is a fresh start, so someone who finds us in week four competes on the same footing as someone who's been here since day one.

Everything lives on the HF26 DEV Challenge Hub: the schedule, every partner category, and the FAQ

Our Prompt

Build something with open-source AI at its core.

Prizes

Every challenge has its own winners, and we'll share each challenge's prizes when it launches. Here's what's up for grabs in the Weekend Challenge.

Overall winner (1): $250, a DEV++ membership, and an exclusive DEV badge.

Featured categories (6): $200 for each winner.

Best Use of Render: Use Render as your project's AI runtime, to host an agent's front end, or to run Hermes or OpenClaw.
Best Use of TabPFN: Use TabPFN, Prior Labs' tabular foundation model, to forecast, predict, classify, or spot anomalies from historical data like a CSV. Use it inside an agent tool (with or without the MCP server) or on its own.
Best Use of Tinker: Use Thinking Machines' Tinker to fine-tune a model for a specific task, and show a clear improvement in performance, latency, or cost over a baseline.
Best Use of Arduino: Build with an Arduino UNO Q: run a model on the board, build a physical agent that senses and acts, or optimize a model for it with Qualcomm AI Hub. Open to anyone building with an UNO Q, whether you got one at an in-person Fest or have your own.
Best Use of DigitalOcean: Build or deploy your project on DigitalOcean: host your app or agent, run an open-weight model on a GPU Droplet (1-Click Models make this quick), or build an agent on the Gradient AI Platform.
Best Use of Gemma: Use Gemma, Google's open-weight model, in building your project: run it locally, fine-tune it, or serve it through Google Cloud or another provider.

Partner categories (10): $100 for each winner.

Best Use of Backboard: Build with R-CLI, Backboard's open-source terminal coding agent, compare open-weight models through a single Backboard API key, or give an open-source project's assistant memory and RAG.
Best Use of ElevenLabs: Give an open-source agent a voice, transcribe audio for a local model, or generate narration for your demo.
Best Use of Entire: Share the agent sessions behind your project in the write-up, or search past agent work to explain why code exists.
Best Use of GitHub Copilot: Build with Copilot's coding agent, the Copilot CLI, or the new Copilot app, automate your project with GitHub Actions, or review contributors' PRs with Copilot.
Best Use of Mastra: Orchestrate an agent over open models, add memory and tools to a chat agent, or build a workflow that triages GitHub issues.
Best Use of MongoDB Atlas: Use Atlas as your data layer: Atlas Vector Search for retrieval, long-term memory for an agent, or the database behind an app built on an open-weight model.
Best Use of Sentry Agent Tracing: Show your agent's work: how it's set up, how it performs (latency, tokens, cost), what you found, and how you debugged it. Include traces or screenshots in your write-up.
Best Use of SerpApi: Give an agent live web search, ground a RAG app in fresh results, or track news for an open-source project.
Best Use of Temporal: Make your agent durable. Wrap it in a Temporal workflow so it survives failures, retries flaky tool calls, and picks up where it left off.
Best Use of Tiger Data: Store embeddings with pgvector, run hybrid keyword and vector search for an agent, or let an agent manage a database through Tiger MCP.

Partner categories may change from challenge to challenge as new partners join. Every winner also gets an exclusive DEV badge, and everyone with a valid submission gets a completion badge. You don't need to use any partner technology to win the overall prize, but if you've been curious about any of this tech, here's your excuse to try it.

Pro Tip: Partner category winners come from a smaller pool of submissions, so your odds are meaningfully higher.

Note: One project can enter every category it genuinely uses, but you can win once per challenge, and we'll aim to celebrate as many different builders as possible across the month.

Free credits: several partners are giving participants credits and promo codes, including Tinker, Render, Backboard, and ElevenLabs. Claim yours at hacktoberfest.com/my.

A huge thank you to our partners for making these prizes possible!

Judging Criteria

This is DEV, so your write-up matters most. A great project with a thin write-up won't win. Tell us the story.

Writing Quality (weighted most heavily): Is the post clear and engaging? Does it explain what you built, who it's for, and why open innovation matters?
Relevance to the Prompt and Theme: Is open-source AI at the core of the project? Does it fit this challenge's theme?
Creativity: Is it an original idea, or a fresh take on a familiar problem?
Technical Execution: Does it work, and is it well built?
Use of Partner Technology (optional): If you're entering a partner category, does the project use that technology in a meaningful way?

Show your work. We'd love to see how you built it. Save your agent session with DevRelay and embed it in your post, or link to it. It's optional, but it helps the judges understand your process.

The Schedule

Challenge	Theme	Launches	Winners Announced
Weekend Challenge	Revealed at launch	Thu Oct 1 (PT/ET), Fri Oct 2 (elsewhere)	Week of Oct 5
Week 1	Revealed at launch	Mon Oct 5	Week of Oct 12
Week 2	Revealed at launch	Mon Oct 12	Week of Oct 19
Week 3	Revealed at launch	Mon Oct 19	Week of Oct 26
Week 4	Revealed at launch	Mon Oct 26	Week of Nov 2

Each challenge's page has its exact deadline in every timezone. Follow the #hf26challenge tag so you don't miss a reveal.

Need Help?

New to Hacktoberfest this year? Start with Everything You Need To Know About Hacktoberfest 2026.
Come hang out and ask questions in the MLH Discord.
Drop questions in the comments below, too.

Happy Hacktoberfest!

[Boost]

Jem — Thu, 01 Oct 2026 16:57:45 +0000

Jess Lee for Major League Hacking (MLH)

Oct 1

Everything You Need To Know About Hacktoberfest 2026: AI Belongs to Everyone 🎃

#hacktoberfest #opensource #ai #devchallenge

8 min read

Congrats to the Summer Bug Smash Winners!

Jem — Thu, 24 Sep 2026 19:32:35 +0000

We are thrilled to announce the winners of DEV's Big Summer Bug Smash powered by Sentry!

This challenge asked you to find your biggest rockstar bugs and give them an epic grand finale, and you delivered. We got real pull requests against real codebases, performance wins measured and verified, and debugging stories that had us cheering in victory.

Thank you to everyone who participated.

Now, let's celebrate our winners!

🐞 Clear the Lineup Winners

Summer Bug Smash: Clear the Lineup 🐛🛹

Sergei Parfenov

Jul 31

The Bug That Crashes Your Import Is the Lucky One

#devchallenge #bugsmash #python #opensource

6 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

vigneshwar

Aug 16

16 Redis commands. 0 spans. A hook that looked perfectly correct.

#devchallenge #bugsmash #opensource #go

7 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

NieJingChuan

Jul 20

How a Missing Secret Made Agent Tool Credentials Predictable, and How We Made It Fail Closed

#devchallenge #bugsmash #security #opensource

7 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Pentine Pejay

Aug 21

An 80-second browser freeze in Zulip's Manage channels, fixed by killing quadratic DOM work

#devchallenge #bugsmash

5 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

MartinDelophy

Jul 21

Fixing a Mobile Click-Through Bug Caused by Unmounting a React Portal on PointerDown

#devchallenge #bugsmash #react #javascript

4 min read

🪲 Smash Stories Winners

Summer Bug Smash: Smash Stories Submission 🐛🛹

xbill for Google Developer Experts

Jul 15

Why did my benchmark stop at N=22? A debugging story in nine bugs

#bugsmash #debugging #ai #python

4 min read

Summer Bug Smash: Smash Stories 🐛🛹

Christo

Jul 26

Ctrl+S said "Saved." The file was 0 bytes.

#devchallenge #bugsmash #cpp #qt

6 min read

Summer Bug Smash: Smash Stories 🐛🛹

Aliaksei Zelianouski

Aug 16

Rise and fall of a self-fixing agent

#devchallenge #bugsmash #agents #ai

12 min read

Summer Bug Smash: Smash Stories Submission 🐛🛹

Aashita

Jul 15

The SSE Fragmentation Catastrophe That Took Down CareerPilot AI

#devchallenge #bugsmash

6 min read

Summer Bug Smash: Smash Stories 🐛🛹

Sergey Inozemtsev

Jul 17

Gemini returned 429 at 2.3% of its documented quota. My retry loop ran for 4 days.

#bugsmash #devchallenge #googlecloud #gemini

6 min read

🛹 Best Use of Sentry Winners

Summer Bug Smash: Clear the Lineup 🐛🛹

Germán Massello

Aug 22

The bug report was wrong, and that was the interesting part

#devchallenge #bugsmash

8 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Asuran

Aug 11

Sentry's trace said gemini-flash-latest. Google served gemini-3.6-flash.

#devchallenge #bugsmash #python #ai

9 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

JonathanSolvesProblems

Aug 19

Python can't weakref a ValueError. Sentry's deduplication found out the expensive way.

#devchallenge #bugsmash #python #debugging

12 min read

✨ Best Use of Google AI Winners

Summer Bug Smash: Clear the Lineup 🐛🛹

Malbolged

Jul 17

Smashing a silent connection leak in node-postgres (pg-pool)

#bugsmash #node #postgres #opensource

7 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Hassan Imam

Aug 22

Two AI debuggers found the same bug. Both stopped one function short.

#devchallenge #bugsmash #python #opensource

9 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Dhruv

Aug 21

Six silent bugs in a voice AI phone line

#devchallenge #bugsmash

12 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Yuva Kunaal

Jul 16

When Batching Your AI Agents Makes Them Read Each Other's Mail

#devchallenge #bugsmash #ai #opensource

7 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Uptime Architect

Aug 1

Zulip logged 'Successfully processed.' Your reply was already gone.

#devchallenge #bugsmash #python #opensource

8 min read

🐛 Runner-Ups

Summer Bug Smash: Clear the Lineup 🐛🛹

Mir Shah

Aug 15

I Used Sentry to Expose a Silent Data-Loss Bug with Zero Errors

#devchallenge #bugsmash #ai #development

9 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Ethan Park

Aug 21

Fix: A Missing .catch() That Crashes Your Entire Node.js Process (ethers.js WebSocket Provider)

#devchallenge #bugsmash

3 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Himanshu Kumar

Jul 20

The smolagents bug that made my agent retry the same valid code three times

#devchallenge #bugsmash #python #ai

4 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Lewis Sawe

Aug 21

Fixing a null-body crash in the Formbricks survey SDK, found by Sentry

#devchallenge #bugsmash

7 min read

Summer Bug Smash: Clear the Lineup 🐛🛹

Talha Anwar

Aug 11

Our SDK Cached One User's Answer and Served It to the Next One Who Asked

#bugsmash #devchallenge #devops #ai

7 min read

Prizes

All winners will receive a cash prize, a DEV++ Membership, and an exclusive DEV badge. Our three Best Use of Sentry winners will also receive a limited edition Sentry skateboard.

All participants with a valid submission will receive a completion badge on their DEV profile.

What's Next?

We've got two other challenges running right now. Join today!

Open-ended scope for custom model testing

Jem for The DEV Team

Sep 23

Join the Kaggle Benchmarking Challenge: $2,500 in Prizes for FIVE Winners!

#devchallenge #machinelearning #ai #kagglechallenge

205

4 min read

Jem for The DEV Team

Sep 18

Join the Sanity Challenge: $2,500 in prizes for FIVE winners!

#sanitychallenge #devchallenge #agents #webdev

268

8 min read

Thanks again to all who participated. This one was really fun.

Happy coding 🐛🛹

Join the Kaggle Benchmarking Challenge: $2,500 in Prizes for FIVE Winners!

Jem — Wed, 23 Sep 2026 20:59:28 +0000

We're excited to team up with Kaggle for a brand new challenge!

Running through October 11, the Kaggle Benchmarking Challenge asks you to build a benchmark, run it against real models, and tell us what you found.

Today's models reason, write code, use tools, and hold multi-turn conversations, and their capabilities will likely change by tomorrow. Public leaderboards only tell you so much, so why not test them against the work you actually do? Kaggle Benchmarks lets you build your own evaluations and run them across a suite of models to see how they really stack up.

So pick something you've always wondered about, measure it, and show your work. There's a $2,500 prize pool up for grabs across five winners!

Read on to learn more.

Our Prompt

Build a Benchmark

Your mandate is to build a benchmark on Kaggle and write about what you learned.

Your post should cover:

What task(s) did you run? Tell us what you're benchmarking and why that capability or behavior caught your interest
Which models did you run it against? Let us know which models you tested and what made them the right lineup
What are the main insights? Share your findings, what surprised you, and what you'd measure next
Where can we see it? Submissions must include a link to your benchmark on Kaggle

The scope is wide open. Benchmark multi-step reasoning, code generation, tool use, image recognition, instruction following, or that one weird failure mode you keep running into. The best benchmarks usually come from a specific itch rather than a general one.

Kaggle Benchmarking Challenge Submission Template

The most compelling submissions will go beyond reporting numbers. Tell us what the results actually mean and what they changed about how you think about these models.

Judging Criteria

All submissions will be evaluated on:

Insights Shared: Do the findings teach us something real about how the models performed?
Writing Quality: Is the post clear, well-structured, and engaging to read?
Creativity in Approach: Is the benchmark itself an original or clever way to measure the capability?

Note: Submissions must include a link to the benchmark on Kaggle to be eligible.

Prizes 🏆

Five winners will each receive:

$500 USD cash prize
DEV++ Membership
Exclusive DEV Badge

All participants with a valid submission will receive a completion badge on their DEV profile.

Getting Started With Kaggle Benchmarks 🚀

New to Kaggle Benchmarks? Here's how it works:

Create a task: Tasks test an AI model's performance on a specific problem, from multi-step reasoning and code generation to tool use and image recognition.
Build a benchmark: Group your tasks into a benchmark and run it across a suite of models.
Check the leaderboard: See how the models stack up and share your results.

Prefer your own setup? You can now create tasks from your local development environment using the Kaggle CLI.

Helpful resources:

Read more from the Kaggle team right here on DEV:

Nicholas Kang (Nick) for Google AI

Jan 14

Introducing Community Benchmarks on Kaggle

#machinelearning #ai #kaggle #datascience

3 min read

Nicholas Kang (Nick) for Google AI

Jun 4

Kaggle is making AI benchmark creation effortless

#ai

3 min read

How To Participate

Build your benchmark on Kaggle, then publish a post on DEV using the submission template provided above and the required challenge tag: #kagglechallenge.

One submission per participant, so make it count!

Please review our judging criteria, rules, guidelines, and FAQ page before submitting so you understand our participation guidelines and official contest rules such as eligibility requirements.

Important Dates

September 23: Kaggle Benchmarking Challenge begins!
October 11: Submissions due at 11:59 PM PDT
November 5: Winners Announced

We can't wait to see what you measure. Questions about the challenge? Drop them in the comments below.

Good luck and happy benchmarking!

DEV Community: Jem

Join the Hacktoberfest Open-Source AI Challenge: Side Hustle! $2,550 in Prizes Across 18 Winners.

This week's theme: Side Hustle

Prize Categories

Judging Criteria

Prizes

How To Participate

Need Help?

Important Dates

Looking Ahead

Congrats to the Hacktoberfest Weekend Challenge: Build for a Friend Winners!

🎉 Congratulations To…

Overall Winner

Featured Prize Category Winners

Best Use of Arduino

Best Use of DigitalOcean

Best Use of Gemma

Best Use of Render

Best Use of TabPFN

Best Use of Tinker

Prize Category Winners

Best Use of Backboard

Best Use of ElevenLabs

Best Use of Entire

Best Use of GitHub Copilot

Best Use of Mastra

Best Use of MongoDB Atlas

Best Use of Sentry Agent Tracing

Best Use of SerpApi

Best Use of Temporal

Best Use of Tiger Data

Prizes

What's Next?

Congrats to Our First MLH x DEV Writing Challenge Winner!

🎉 Congratulations To…

This Month's Winner

Prize

Just got back from a hackathon?

What's Next?

Top 7 Featured DEV Posts of the Week

Join the Hacktoberfest Open-Source AI Challenge: Touch Grass! $2,450 in Prizes Across 17 Winners.

This week's theme: Touch Grass

Prize Categories

Judging Criteria

Prizes

How To Participate

Need Help?

Important Dates

Join the Hacktoberfest Weekend Challenge: Build for a Friend! $2,450 in Prizes Across 17 Winners. Submissions Due October 5 at 6:59 AM UTC.

Our Prompt: Build for a Friend

Prize Categories

Judging Criteria

Prizes

How To Participate

Need Help?

Important Dates

Congrats to the DEV Weekend Challenge: Generosity Edition Winners!

🎉 Congratulations To…

Overall Winner

Best Use of Snowflake

Best Use of ElevenLabs

Best Use of Google AI

Best Use of Solana

Prizes

What's Next?

Hacktoberfest 2026 DEV Challenges: Five Challenges, One Prompt, a New Theme Every Week

How It Works

Our Prompt

Prizes

Judging Criteria

The Schedule

Need Help?

[Boost]

Top 7 Featured DEV Posts of the Week

Congrats to the Summer Bug Smash Winners!

🐞 Clear the Lineup Winners

🪲 Smash Stories Winners

🛹 Best Use of Sentry Winners

✨ Best Use of Google AI Winners

🐛 Runner-Ups