DEV Community

Cover image for I Wrote 100,000 Lines of Code in 6 Months Leading an SNS App Contract. Here’s What I Learned
Chris
Chris

Posted on

I Wrote 100,000 Lines of Code in 6 Months Leading an SNS App Contract. Here’s What I Learned

Six months.

100,000 lines of code.

And a whole lot of context switching.

This post is a reflection on one of the most intense and rewarding contracts I've ever taken on. I led the development of a full-fledged SNS (social networking service) app from scratch for a client that had a clear goal… but little technical knowledge. Our deadline? Six months.

🧠 What I Was Responsible For

Basically… everything.

  • Project planning and roadmap creation
  • Tech stack selection
  • Leading development (including writing a huge chunk of the code myself)
  • Mentoring juniors and interns
  • Acting as sales engineer — navigating client meetings, translating technical requirements, and proposing solutions
  • Consulting the client on how tech could meet their business goals

🧱 Tech Stack

I chose a modern, scalable stack that balanced developer productivity with performance:

  • Frontend: React + Chakra UI
  • Backend: NestJS (with modular architecture and clean code principles)
  • Infrastructure: Google Cloud Platform (Cloud Run, Firestore, Firebase Auth, etc.)

It let us move fast, deploy flexibly, and keep everything manageable as the project grew.

📊 The Numbers

  • 100,000+ lines of code (frontend + backend)
  • 6 months
  • Team size: 2 juniors + myself
  • 1 senior engineer = me

💥 The Biggest Challenges

1. Context switching

I went from fixing bugs to answering junior questions to preparing slide decks for client meetings — sometimes all within the same hour. Staying sharp while switching between business, dev, and mentoring was brutal.

2. Communicating with a non-technical client

Our client had passion, vision, and drive — but not much technical understanding. That meant I had to constantly reframe problems in non-technical terms, manage expectations, and explain why certain things take time or need to be done "the right way."

3. Balancing speed with quality

With only six months, we had to move fast — but I didn’t want to build something that would collapse under real users. I focused on clean architecture, modular components, and testing — while still shipping fast.

4. Mentoring while building

Teaching interns and junior devs while also being the primary coder meant I had to document decisions well, review code thoroughly, and make sure they weren’t blocked — all without slowing down the project.

💡 What I Learned

  • You can’t build something great alone, but sometimes you have to lead alone.
  • Good documentation and reusable components saved my sanity.
  • Clients don’t need to understand code — they need to trust your decisions. That trust is built through clear, frequent, honest communication.
  • Teaching others made me a better engineer — I had to deeply understand what I was doing in order to explain it.

🏁 Final Thoughts

Would I do it again?

Honestly… yes.

It pushed me past what I thought I could do and gave me battle-tested confidence in leading full-cycle product development — from first client call to production deployment.

If you’re in the trenches right now leading a project like this: stay sharp, stay humble, and remember that even when you’re deep in the code, you’re building something that matters.

Sentry blog image

How to reduce TTFB

In the past few years in the web dev world, we’ve seen a significant push towards rendering our websites on the server. Doing so is better for SEO and performs better on low-powered devices, but one thing we had to sacrifice is TTFB.

In this article, we’ll see how we can identify what makes our TTFB high so we can fix it.

Read more

Top comments (0)

AWS Q Developer image

Your AI Code Assistant

Automate your code reviews. Catch bugs before your coworkers. Fix security issues in your code. Built to handle large projects, Amazon Q Developer works alongside you from idea to production code.

Get started free in your IDE

👋 Kindness is contagious

Explore a trove of insights in this engaging article, celebrated within our welcoming DEV Community. Developers from every background are invited to join and enhance our shared wisdom.

A genuine "thank you" can truly uplift someone’s day. Feel free to express your gratitude in the comments below!

On DEV, our collective exchange of knowledge lightens the road ahead and strengthens our community bonds. Found something valuable here? A small thank you to the author can make a big difference.

Okay