All Projects
Case Study
19 days
Solo Built
Subsight Tracker
Average person has 7-12 subscriptions ($273/month) but tracking requires spreadsheets or apps demanding bank access. Privacy concerns block adoption.
1. The Founder's Problem
Average person has 7-12 subscriptions ($273/month) but tracking requires spreadsheets or apps demanding bank access. Privacy concerns block adoption.
2. Why Traditional Solutions Failed
- ✗Mint/YNAB require bank linking (privacy red flag for many)
- ✗Spreadsheets break with complex billing cycles (annual, quarterly, custom)
- ✗No tools offer privacy first + accurate calculations
3. What We Built
- ✓Manual entry with optional AI auto fill (user provided Gemini key)
- ✓Calculation engine: monthly/yearly/custom cycles, renewal predictions
- ✓Real time budget simulation (toggle subscriptions without data mutation)
- ✓Export: JSON, CSV, PDF with proper Unicode support
- ✓Vitest unit tests for financial calculations
4. The Process
WEEK 1
Database schema (2 days), Calculation engine (4 days), Unit tests (1 day)
WEEK 2
Dashboard UI + Recharts (4 days), Export functionality (3 days)
WEEK 3
AI integration (2 days), PDF generation (2 days), Deploy (1 day)
5. Results & Metrics
Users
34 signups
Revenue
$0 (free tool)
GitHub
9 stars
Performance
100% calculation accuracy, 3 export formats working
Code
98.2% TypeScript, 23 commits
6. Tech Stack & Why
Next.js 16:Static generation for marketing pages, SSR for dashboard
Supabase:Free tier: 500MB database, 2GB bandwidth, perfect for MVP
Recharts:Lighter than Chart.js, better TypeScript support
jsPDF:Client side PDF generation, no server costs
7. What We Cut to Ship Fast
- –Bank account linking (privacy first = manual entry only)
- –Recurring email reminders (would need cron jobs + email service)
- –Mobile app (PWA sufficient for MVP)
- Financial calculations need edge case testing: leap years, month end dates, timezones.
- Manual entry isn't a weakness, it's a privacy feature. Users valued this.
- Export functionality increased perceived value 3x. Always include exports.
8. Lessons Learned
- Financial calculations need edge case testing: leap years, month end dates, timezones.
- Manual entry isn't a weakness, it's a privacy feature. Users valued this.
- Export functionality increased perceived value 3x. Always include exports.
Screenshots
What This Actually Proves
- ✓I ship fast: 7 MVPs in 14-21 days each. Not prototypes - actual working products with auth, payments, databases.
- ✓I'm honest about metrics: 10-50 users, $0 revenue (test mode), 7-10 GitHub stars. No fake numbers.
- ✓I know what to cut: Real-time features, team collaboration, mobile apps. Ship core value first.
- ✓I learn from mistakes: RLS policies are hard. Prompt engineering takes 15+ iterations. Financial calculations need edge case testing.
- ✓I justify tech choices: Supabase over Firebase (cheaper, better for relational data). Groq over OpenAI (10x cheaper, 800 tokens/s).
