Docker Image Size Bloat from Build-Time Dependencies Leaking into Production Layers

Docker images for production services routinely reach 1-3 GB because build-time dependencies (compilers, dev headers, package managers, test frameworks) leak into the final image layer due to incorrect multi-stage build configuration or single-stage Dockerfiles. So what? Larger images increase container pull times from registries, adding 30-90 seconds to pod startup during scaling events or node replacements, directly extending recovery time during incidents. So what? Slow pod startup means autoscalers cannot respond to traffic spikes quickly enough, causing request queuing, elevated latency, and user-facing errors during load bursts. So what? To compensate, teams over-provision baseline capacity with extra replicas running 24/7, inflating compute costs by 20-40% beyond what right-sized images would require. So what? Over-provisioned clusters consume cloud budget that could fund new features or hire additional engineers, creating an invisible tax on engineering velocity. So what? The cost is invisible because nobody traces per-service cloud spend back to image size decisions, so the problem persists indefinitely without accountability. The structural root cause is that Dockerfiles are written by application developers who optimize for 'it builds and runs' rather than image size, and there is no automated gate in CI pipelines that rejects images exceeding a size threshold or flags unnecessary layers.