How Hard-Coded Interest Rates Cost a Fintech $2M

A fintech startup hard-coded interest rate logic into its API layer to launch quickly, but 18 months later that shortcut led to $2M in losses from remediation, velocity tax, incidents, and missed opportunities. Changing the rate model took three months instead of weeks because the logic was embedded in seven undocumented downstream processes. The case illustrates that technical debt is a finance problem, not just a developer frustration.