From zero to a production financial application.
STWLTH Wealth is our own product. We treated it like a client engagement: define the problem, build the system end to end, ship it to production, and keep improving it in public.
Financial tools want your bank login.
Most personal-finance software starts by asking you to link your accounts, then spends the next hour on setup. The bet behind STWLTH Wealth: people planning for early retirement want fast answers to specific questions — when can I stop working, what does one more year buy me, should I rent or buy — without handing over their data.
What we built.
Financial modeling
Compound growth, FIRE targets, amortization, tax brackets for 50 states + DC, Social Security timing, Roth conversion ladders with Medicare IRMAA warnings, and backtests over Shiller market data from 1871–2022.
Accounts & payments
Clerk authentication, Stripe subscriptions with signature-verified, idempotent webhooks, a customer portal, and a referral program with automatic credits.
Data & privacy
PostgreSQL on Supabase with row-level security. No bank-account linking; the free calculators run entirely in the browser.
AI assistant
An in-app assistant that reads the user's scenario, behind one API that can route to Claude, OpenAI, or Gemini, with per-user quotas, answer caching, and bring-your-own-key support.
Installable & offline
A progressive web app with a service worker: free calculators work in airplane mode, while account and paid routes are never served from cache.
Security & quality
An enforced Content-Security-Policy, security headers, WCAG 2.1 AA accessibility work, and CI that type-checks, lints, builds, and runs unit and end-to-end tests on every pull request.
What it runs on.
- Next.js
- React
- TypeScript
- Tailwind CSS
- Supabase / PostgreSQL
- Clerk
- Stripe
- Vercel
- Playwright
- Vitest
- Claude / OpenAI / Gemini
What we can prove.
- Product strategy
- Financial modeling
- Full-stack engineering
- Payments
- AI
- Privacy architecture
- PWA
Need something built this thoroughly?
Describe the workflow, the spreadsheet, or the system that doesn't talk to the others. You'll get a straight answer about whether software fixes it — and what it would take.
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