FinTrack

Intentionally built as a proof-of-concept for systems-thinking capability, not to solve a personal problem. Deployed live in production as proof of execution rigor.

The Problem & Constraint-First Thinking

Expert accountants expensive & slow. SMK/magang-level admin do data entry. Management needs accurate P&L visibility.

Operator (SMK/magang) unfamiliar with laptop/complex software. Solution: Telegram bot interface (mobile-first, familiar, low friction). Result: zero IT training needed, day-1 usable.

Prevent duplicate entry (retried webhook deliveries), unauthorized changes, fraud. Solution: an idempotency key on every Telegram delivery plus an API logic layer hidden behind the bot. Result: system enforces rules, operator cannot bypass, every change attributed to an actor.

Key Metrics

Manual Cycle Time

2 hours5 minutes

Anomaly Detection

Manual reviewAutomated (Z-score, 2.5σ threshold)

Update Frequency

End-of-day batchReal-time

Solution Architecture

Frontend
Vite + React dashboard (analytics, account search, real-time P&L view)
Backend
Supabase PostgreSQL (single-entry running balance, anomaly detection)
Input Layer
Telegram Bot (Python) connected to the API
Deployment
Vercel (frontend), Railway (bot + backend logic)
Methodology
Vibe coding with Claude — AI-augmented development, not manual coding

Lessons Learned

Initially assumed Supabase's free tier was sufficient for anomaly-detection queries. At 1,000+ transactions, query latency increased. Solution: incremental Z-score calculation with a caching layer. Learning: production-level accounting systems must pre-optimize for scale, not react to it after the fact.