What is progressive delivery, and what tools enable it (Argo Rollouts, Flagger)?
CI/CD & GitOps · Advanced level
Answer
Progressive delivery is controlled rollout with automated validation, such as canary, blue-green, traffic shifting, and feature-flag rollout. Tools include Argo Rollouts, Flagger, service meshes, ingress controllers, and observability systems that feed promotion decisions.
Technical explanation
Safe release design assumes rollback may be needed and separates code deployment, data changes, and user exposure.
Compatibility windows and observability are mandatory when application and database versions overlap.
GitOps separates build from deploy: CI produces immutable artifacts, while the GitOps controller reconciles declarative desired state into the cluster.
Argo CD status has two dimensions: sync status indicates desired versus live state; health status indicates whether live resources appear operationally healthy.
Use projects, RBAC, repository allowlists, destination restrictions, sync windows, and admission policies to constrain what an Application may deploy.
Prefer reviewed Git changes over direct kubectl changes; direct changes create drift and bypass audit, policy, and promotion workflow.
Hands-on example
1. Design an advanced delivery exercise for: What is progressive delivery, and what tools enable it (Argo Rollouts, Flagger) using one service, one Git repository, one artifact registry, and one Kubernetes environment.
2. Build once from a protected branch, generate test reports, SBOM, vulnerability scan results, provenance metadata, and a container image tagged by both semantic version and digest.
3. Sign the image or artifact, verify the signature in the deployment pipeline, and promote the same digest through dev, staging, and production without rebuilding.
4. Use progressive exposure where relevant: feature flag off by default, canary 5%, automated metric check for error rate and latency, then expand or rollback.
5. Record audit evidence: PR, approver, pipeline run, artifact digest, SBOM location, signature verification result, deployment event, and rollback or forward-fix decision.
Check how well your resume matches the role with our free resume checker— match score, ATS check, and the skills you're missing.
More CI/CD & GitOps interview questions
- What is CI/CD, and what is the difference between continuous delivery and continuous deployment?
- What are the goals of a CI pipeline beyond just running tests?
- What is Jenkins, and what is the difference between a controller and an agent?
- What is the difference between a freestyle job and a pipeline job in Jenkins?
- What is the difference between a declarative and a scripted Jenkins pipeline?
- What is a Jenkinsfile, and why keep your pipeline as code in the repo?
- Explain the structure of a declarative pipeline (agent, stages, steps, post).
- What is the post section used for, and what are its conditions (success, failure, always)?