CI/CD · Ship safely, repeatedly
Which CI/CD metrics actually matter?
Short answer
Use the DORA measures: lead time for changes, deployment frequency, change failure rate and time to restore. Pair them with pipeline duration and queue time, and avoid using them as individual performance targets.
The four DORA metrics describe delivery outcomes rather than activity. Lead time measures from commit to production, deployment frequency measures batch size, change failure rate measures quality, and time to restore measures recovery capability.
- Lead time for changes: median time from merged commit to running in production
- Deployment frequency: how often the team releases to production
- Change failure rate: share of deployments that require remediation
- Time to restore: how quickly service is recovered after a failure
- Supporting metrics: pipeline duration, queue time, flake rate and rollback rate
- Segment by service and team, and track trends rather than single data points
lead_time_p50 = median(deployed_at - merged_at)
deployment_frequency = releases / days
change_failure_rate = failed_releases / total_releases
time_to_restore_p50 = median(restored_at - incident_started_at)Follow-ups you should expect
Interviewers use these to check whether the first answer was understanding or memorisation.
- 1How would you instrument lead time?
- 2What counts as a failed deployment?
- 3Why can deployment frequency be gamed?
- 4How do you use these metrics without blaming individuals?
Say it in the interview
I use the four DORA metrics: lead time, deployment frequency, change failure rate and time to restore. I pair them with pipeline duration and queue time to explain the delivery experience. I segment by service and look at trends, not individual scores, because these measures are easy to game. The point is to find system constraints, not to rank engineers.
Use this as a model, not a script. Saying it in your own words is what makes it survive follow-up pressure.
Related questions
Reading is step one
Now say it out loud.
Understanding an answer and delivering it under pressure are different skills. Rehearse this topic in a live CI/CD mock interview and get scored feedback on depth, clarity and confidence.