I Built a Production-Ready Biometric Auth Microservice. Here Are 5 Problems Nobody Warns You About.

Everyone talks about biometric authentication as the future of security. Fingerprint scanning, face recognition, liveness detection... it all sounds elegant in a conference talk or a product demo. Then you actually start building one, and reality shows up uninvited. I built a biometric authentication microservice from scratch. Not a wrapper around someone else's API. A standalone, production-ready, multi-tenant service with its own recognition pipeline, anti-spoofing layers, and encryption stack. The goal: offer it as a SaaS product that other applications can plug into. This post is not a tutorial. I'm not going to walk you through code or tell you which libraries to use. Instead, I want to share 5 real problems I ran into during this process. These are things you won't find in documentation, Stack Overflow answers, or "Getting Started with Biometrics" blog posts. You only learn them by building. 1. Liveness Detection is Harder Than Face Recognition Here's what most people assume: the