DEV Community

Cover image for Start Small, Ship Something: What Two Hack Days Taught Me About Building a Community
Toheeb Olanrewaju Olagoke
Toheeb Olanrewaju Olagoke

Posted on AI-assisted

Start Small, Ship Something: What Two Hack Days Taught Me About Building a Community

#hacktoberfest #opensource #ai #community

In October and November 2026, my community ran two Hacktoberfest Hack Days with Major League Hacking (MLH): one at Luton Central Library on 24 October, and one at College Lane in Hatfield on 4 November.

Dozens of students and beginners came to play games, build projects with open AI models, and submit them to a judging panel. This is how it started, what happened, the small open-source app I built for it, and what I would tell anyone thinking of running their own.

How it started

I run Xtructure, a tech community for students and early-career builders, and CTRL + Chat, my own tech show and podcast. Xtructure started in February 2026, when a friend and I came together to help students learn AI and build things with it. We also wanted to create a fun, welcoming space to network, where everyone feels they belong and can grow in confidence.

This year, Hacktoberfest focused on open-source AI. MLH lets organisers run free "Hack Days": mini hackathons for their own community. I applied to host one because many of our members had never built with AI or shipped a project.

The plan was simple:

  1. Play games to break the ice.
  2. Learn something practical about open source.
  3. Build in teams.
  4. Submit to judges.

The two prize categories were Best Use of Gemma 4 and Best Open-Source AI Project.

The team

No one person runs an event like this. I looked after the games and the hackathon session. A friend led the open-source and deployment workshop, and volunteers, judges and the Luton Library management team made the day work.

Major League Hacking provided the platform, swag and support, and ElevenLabs donated credits for the builders.

Hack Day 1: Luton, 24 October

46 people registered, and 42 checked in at Luton Central Library for a free, 18+ day from 10:00 to 16:00. Local press coverage beforehand helped spread the word.

We opened with games and a quiz, then moved to the build session. Teams worked with open or open-weight AI, using tools like Gemma 4 and ElevenLabs. Projects were submitted through the MLH platform, and a panel picked winners in both categories.

The organiser demo: Hack Day Voice Helper

I built a small app for the event that uses three things: Gemma 4 for the answers, ElevenLabs for the voice, and open source for the code (MIT).

You type a question about the Hack Day, Gemma answers, and ElevenLabs reads the answer aloud. I entered it as an organiser demo, so it wasn't eligible for prizes.

Three ideas made it more trustworthy than a typical demo.

1. Ground the model in facts

I put the real event details in the prompt and told Gemma to answer only from them, and to say "I don't know" otherwise. This stops it inventing times or prizes.

EVENT_FACTS = """
- Event: CTRL + Chat Hack Day, part of Hacktoberfest 2026, with Major League Hacking.
- Date: Saturday 24 October 2026, 10:00am to 4:00pm.
- Venue: Luton Central Library, Luton.
- Free to attend, for students aged 18 and over.
"""

prompt = (
    "You are a friendly helper for a student hackathon.\n"
    f"Facts about the event:\n{EVENT_FACTS}\n"
    "Answer the question briefly, using only the facts above. "
    "If the answer is not in the facts, say you don't know.\n\n"
    f"Question: {question}"
)
Enter fullscreen mode Exit fullscreen mode

2. Plan for temporary errors

Early on, the API returned temporary server errors. I added a retry and a backup model, so the demo doesn't fall over in front of an audience.

MODELS = ["gemma-4-26b-a4b-it", "gemma-4-31b-it"]
TRIES_PER_MODEL = 2

def ask(client, question):
    last_error = None
    for model in MODELS:
        for attempt in range(TRIES_PER_MODEL):
            try:
                response = client.models.generate_content(model=model, contents=prompt)
                return response.text
            except Exception as err:
                last_error = err
                time.sleep(2 * (attempt + 1))
    raise last_error
Enter fullscreen mode Exit fullscreen mode

3. Keep your keys out of the code

API keys live in environment variables, never in the repository. On a cloud host, I set them as encrypted environment variables and ran the Flask app with gunicorn.

export GEMINI_API_KEY="your key"
export ELEVENLABS_API_KEY="your key"
python app.py
Enter fullscreen mode Exit fullscreen mode

The full code is on GitHub: Hack Day Voice Helper.

Hack Day 2: Hatfield, 4 November

The Hatfield Hack Day didn't go to plan at first. It was originally due on 21 October 2026, but the venue approval took longer than expected. MLH's Hack Days team was supportive and told us we were free to reschedule, so we fixed a new date of 4 November.

Before then, we ran a smaller session that included a talk on open source and Gemma. We wanted to reach more people, so we held the full event on 4 November. About 15 people attended, which made it more hands-on. It was great to see everyone turn up and push something to the submission.

What I learned

  1. Check the rules before you spend. MLH reimburses food and drinks, but other costs need approval in advance. Email the team before you book or pay for anything unusual, like a venue.
  2. Keep check-ins up to date on the day. Attendance is recorded on the organiser dashboard, and you can't fix it after the event.
  3. Set the submission deadline early, and repeat it. Judging is calmer when projects are in before the build session ends.
  4. Plan for failure. API errors, WiFi and venue changes all happen. A backup plan matters more than a perfect schedule.
  5. Keep keys and codes private. API keys never go in a repository, and winners' coupon codes go out by private message.
  6. Be clear about age and safeguarding. Decide who can attend, say it on the sign-up page, and keep under-18s out of photos.
  7. Keep the organiser out of the prizes. If you build something yourself, enter it as a demo.

Thank you

Thank you to Major League Hacking and Hacktoberfest for the platform and support, to ElevenLabs for the credits, to Luton Central Library for hosting us, and to everyone who came, built something, and asked questions.

What's next: our participants have been asked to finish their projects, and we're giving them virtual support. We're planning a meet-and-greet in December, our next Hack Days will be virtual, and a new episode of CTRL + Chat is on the way. If you want to run a Hack Day in your own town, get in touch. I'm happy to share what I learned.

Start small. Ship something. Show it off.

I'm Toheeb, a software and AI engineer, and I co-founded the Xtructure community and the CTRL + Chat show.

Top comments (0)