Why Your Docker Builds Aren't Reproducible (And How to Fix Them)

Loose version specifiers in Docker requirements.txt cause non‑deterministic builds, risking compliance in regulated environments. HSTS missing warnings persist because scanners check redirects, different hostnames, error pages, or alternate ports, not just the header. JavaScript’s floating‑point imprecision leads to money‑math bugs where 0.1 + 0.2 ≠ 0.3, causing rounding errors in loan calculators. Practical fixes include using integer cents, strict version pins, and ensuring HSTS headers are served on the correct redirect chain.