The most dangerous move on a regulated fintech system? Assuming you understand it before you actually do.

Rule number 1 in development: never assume anything.

Here's what it looked like when we extended a live institutional trading platform - AFSL-licensed, handling perpetuals, spot, options, and FX - without a single regression, in production, with people watching very closely.

We joined a live system that was already in production

This wasn't a startup with a blank slate. The platform was already live - real users, real trades, real regulatory obligations. The core system ran on C#/.NET and PostgreSQL, with a separate compliance portal handling KYC/AML and onboarding.