Building Noteng — A Collaborative Note-Taking App

Every semester the question is the same: "Wait, what did sir say about that sorting algorithm?". Notes get lost in WhatsApp chats. Someone screenshots the board but it's blurry. Someone else has a perfect handout but only shares it three hours before the exam.

Noteng started as a rant in a 2 AM commit message and ended up being one of our most-used internal projects.

The Problem

College note-sharing is broken in a very specific way. It's not that students don't want to share — they do. It's that there's no good place to do it. Google Drive folders get disorganised. WhatsApp groups get noisy. Notion is too heavy for casual sharing.

We wanted something with zero friction: open the link, see the notes, done.

Architecture Decisions

We chose React for the frontend and Firebase for the backend — not because it was the most interesting stack, but because it let us move fast and deploy instantly. The real-time sync came for free with Firestore.

const notesRef = collection(db, "courses", courseId, "notes");
const q = query(notesRef, orderBy("createdAt", "desc"));
onSnapshot(q, (snapshot) => {
  setNotes(snapshot.docs.map(d => ({ id: d.id, ...d.data() })));
});

The hardest part wasn't the tech — it was the access model. Who can edit? Who can just view? We went through three different permission models before landing on something that felt right.

What We Learned

Shipping is humbling. The first version had a bug where notes would duplicate themselves on every refresh. We found it two hours before a demo and fixed it in the worst possible way (localStorage as a dedup cache). It held up.

The real lesson: done is better than perfect, especially when your users are your friends who will roast you mercilessly if it breaks.

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If you want to dig into the code, the repository is open. PRs welcome.