Tax & accounting SaaS
PayTaxNZ
A legacy Laravel tax platform rebuilt as a Next.js and TypeScript monorepo, running as 7 Docker services behind Caddy and Cloudflare.
- Tax engine built from 186 golden assertions written before implementation, now 1,100+ automated tests.
- 1,070 results reconciled against the legacy system: 999 exact matches, 71 documented differences, 0 unexplained.
- Multi-tenant data secured with PostgreSQL row-level security, decimal maths and idempotent writes.
- 8-language UI, invoicing, outbox email and an AI-assisted document inbox.
- Next.js 15
- TypeScript
- PostgreSQL 16
- Drizzle
- oRPC
- pg-boss
- Docker