What are signed commits (git commit -S), and why use them?
Answer: Signed commits ensure authenticity — they’re cryptographically verified with a GPG or SSH key, proving the commit really came from you and wasn’t tampered with. Setup: Generate a GPG key: gpg --full-generate-key
What interviewers expect
- A clear definition tied to Version Control in Git & GitHub projects
- Trade-offs (performance, maintainability, security, cost)
- When you would and would not use it in production
Real-world example
In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.
How to explain in the interview
- Define the concept in one or two sentences.
- Context — where it fits in Git & GitHub architecture.
- Example — a specific project, bug, or performance win.
- Trade-off — what you gain vs what you sacrifice.
Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.