Working in regulated financial systems changes how you think about code. Every decision carries weight — not just technical debt, but legal and financial risk. Here’s what I’ve learned.
Correctness Over Cleverness
In fintech, a clever optimization that’s hard to audit is worse than a straightforward implementation that’s easy to verify. Code review isn’t just about style — it’s about provability.
Testing at the Boundaries
Unit tests are table stakes. What matters more is integration testing against real payment processors, end-to-end compliance checks, and chaos testing for failure modes that only surface under load.
The Human Side
The hardest part isn’t the code. It’s building systems that make compliance easy for the people who use them. A well-designed internal tool can prevent more incidents than any amount of automated monitoring.