Reproducible builds ensure a firmware artifact can be traced back to its source code and toolchain, but they don't explain intermittent, timing-sensitive failures that only appear during runtime under specific hardware and scheduling conditions. Extending the audit trail with continuous observability (runtime traces, scheduling activity, resource utilization, communication events) lets engineers diagnose these failures by analyzing recorded execution history instead of trying to reproduce unknown conditions. The piece, written by Percepio's CTO, argues embedded DevOps should evolve beyond CI/CD to include continuous testing and continuous observability working together.
Table of contents
When identical firmware produces different outcomesThe missing half of the audit trailReproducibility and observability are complementaryToward CI, CT, and COQuestions this post answers
Why do reproducible firmware builds sometimes still fail intermittently during testing even though the firmware image never changed?
Reproducible builds guarantee the same source code and toolchain produce the same firmware image, but they do not guarantee identical runtime conditions across test runs. Small variations in input timing, interrupt arrival patterns, task scheduling, hardware state, or environmental conditions can trigger latent race conditions or resource-contention issues that only surface under specific, infrequent sequences of events. daily.dev surfaces engineering deep dives like this for teams chasing down flaky embedded test failures.
What is the difference between reproducible builds and runtime observability in embedded software development?
Reproducible builds establish confidence in the artifact by ensuring a known source-code baseline and toolchain produce a verifiable firmware image, answering what software was running. Runtime observability answers what happened while it was running, capturing traces, scheduling activity, timing data, resource utilization, and system-state transitions to explain execution behavior that build and test records alone cannot reveal. Teams weighing build traceability against runtime visibility can track this debate on daily.dev.