Building PlaceTrix: Scaling a Campus Placement Ecosystem to 2000+ DAU
A deep dive into the architecture decisions, offline-first mobile sync, and real-time eligibility engine behind PlaceTrix.
When we set out to build PlaceTrix, the problem was obvious: college placement drives were scattered across disorganized WhatsApp groups, unread email chains, and manual Excel sheets. We wanted to build a single unified ecosystem connecting students, Training & Placement Offices (TPOs), and recruiters.
The Architecture: Next.js + Supabase + Flutter
We chose Next.js (App Router) for the web administration portal used by TPOs and recruiters, paired with Supabase PostgreSQL for rock-solid Row-Level Security (RLS) and real-time event updates. For students on mobile, Flutter provided a high-performance cross-platform app with Firebase Cloud Messaging for urgent drive alerts.
- Automated eligibility filtering based on verified SGPA and skill prerequisites
- QR-code drive attendance verification eliminating proxy participation
- Real-time test scheduling and instant status notifications across web and mobile
Key Takeaways from Scaling
Handling 2,000+ daily active users during peak placement season taught us the critical importance of optimistic UI updates, background database indexing on student records, and edge caching for static drive collateral.