Why Trading Platforms Are Among the Hardest Software to Build
Most software has a generous margin for error. A bug in your e-commerce checkout means a failed transaction — annoying, recoverable. A bug in your trading platform's order matching engine means incorrect executions, real financial losses, and potentially regulatory consequences. The gap between "it works" and "it works correctly under all market conditions" is wider in trading software than almost anywhere else.
I've spent time building and reviewing trading platforms across retail brokerage, institutional execution, and DeFi. This post is a practical engineering guide: the architecture decisions that matter, the features you can't cut corners on, and the failure modes that will bite you if you're not prepared.
This is not financial advice, and building a regulated trading platform requires legal and compliance expertise beyond the scope of any engineering post. What this covers is the engineering substance of the problem.
The Core Components Every Trading Platform Needs
