SYSTEM / 02
PAYE Revenue Management System
Nationwide PAYE computation, reconciliation and regulatory reporting infrastructure.
ROLEFullstack Engineer
PERIOD2025—Present
ARCHITECTURETransactional / Auditable
01 / CONTEXT
A system shaped by real-world constraints.
The system supports PAYE computation, interstate reconciliation and regulatory reporting across employers, state revenue services and federal administrators.
02 / ROLE & OWNERSHIP
Where I contributed.
- Full-stack engineering across tax computation, reporting, reconciliation and jurisdiction-aware access control.
03 / CONSTRAINTS
What made the work difficult.
- Tax rules needed to evolve without making historical calculations impossible to explain.
- Every action and report needed to respect national, state, organisation and branch boundaries.
04 / ENGINEERING DECISIONS
What mattered technically.
Versioned computation
Built PAYE calculation around configurable, versioned tax rules so results remain attributable to the rules that produced them.
Scoped administration
Applied jurisdiction-aware RBAC across national, state, organisation and branch scopes.
Traceable reconciliation
Supported interstate reconciliation with employer and state drill-down reporting.
05 / RELIABILITY & SECURITY
Correctness beyond the happy path.
- Critical changes use atomic transactions and idempotent verification.
- Immutable audit records preserve an explainable history of financial operations.
06 / TECHNOLOGY
Technology should support the system, not become the story.
TypeScript · NestJS · PostgreSQL · Redis · AWS · Terraform · Jest