Identity, secrets, supply chain and adversarial risk.
3 items at expert level · all topics
How do you safely rotate IAM credentials or database secrets without downtime?
The safe pattern is overlapping validity. Create the new secret while the old one still works, get code that accepts either one deployed everywhere, confirm the new one is actually being used, then revoke the old one. Rotating in a single step guarantees a window where something is still holding a credential that no longer works.
Someone force-pushed main at 2 AM. How do you investigate?
Preserve evidence first, then answer four questions: what was main before, what is it now, who did it, and was anything deployed from the rewritten history. Treat it as potentially malicious until the audit log says otherwise, because a force-push at 2 AM is an unusual enough event to earn that default.
An attacker steals a developer's Git credentials and pushes malicious code. How do you defend against this?
Assume one credential will eventually be stolen and design so that alone isn't enough to ship code. Layer identity, branch protection, review, signing, pipeline isolation and detection, and remember the attacker's real target is usually the CI workflow, not the application code itself.