HL Internal Finance
Internal finance management app for tracking budgets, transactions, and reporting inside an organization.
the problem
Internal budget tracking for a small organization usually lives in a shared spreadsheet: no real audit trail, no PDF exports for stakeholders, and rounding errors from doing money math in plain floating point.
approach
A Next.js finance app that uses decimal.js for exact monetary arithmetic instead of native floating-point numbers, @react-pdf/renderer to generate real PDF reports as React components rather than calling out to an external service, and jose-signed JWT sessions backed by a Prisma/Postgres user store.
architecture
decimal.js for money
Every monetary calculation goes through exact decimal arithmetic, sidestepping the classic 0.1 + 0.2 floating-point rounding bug.
@react-pdf/renderer
PDF reports generated server-side as real React components sharing the same data model as the UI, not a separate templating system.
jose + Prisma auth
Signed JWT sessions backed by a real Postgres-via-Prisma user store, not a hardcoded credential.