Observability & Monitoring
Can you explain the 'Three Pillars of Observability'?
Can you explain the RED method and the USE method for monitoring, and when each applies?
How do you decide what belongs in a metric, a log, or a trace when instrumenting a system?
What is distributed tracing, and why is it important in a microservices architecture?
What is the difference between "Monitoring" and "Observability"?
What is the difference between "Structured Logging" and "Unstructured Logging," and why does it matter for DevOps?
What is the difference between push-based and pull-based monitoring, and what are the trade-offs?
What is the difference between synthetic monitoring and real user monitoring?
Containers & Orchestration
Can you explain the concept of 'Sidecar' containers and why they are used in a DevOps context?
How do containers support the "Build Once, Run Anywhere" principle in DevOps?
How does adopting serverless/FaaS change your delivery and operational responsibilities?
What are the delivery and operational trade-offs of a microservices architecture versus a monolith?
What is "Container Orchestration," and why is it necessary once you move beyond a few containers?
What is "Service Discovery," and why is it a core requirement of containerized microservices?
What problem does containerization solve for a developer that a Virtual Machine does not?
Can you explain the relationship between SLIs, SLOs, and SLAs?
How can DORA metrics be gamed or misinterpreted by management?
How do you determine if an alert is actionable vs. noise?
How do you distinguish between a 'Vanity Metric' and an 'Outcome Metric' in a delivery pipeline?
How does your choice of branching strategy impact your "Lead Time for Changes" (DORA metric)?
If your 'Change Failure Rate' is high but your 'MTTR' is low, what does that tell you about your team's process?
If your Change Failure Rate is high but your Deployment Frequency is also high, what does that tell you about your pipeline?
What are the DORA metrics, and how do they help measure the effectiveness of a DevOps practice?
What are the Four Golden Signals of monitoring?
What is an "Error Budget," and how does it help balance feature velocity with system stability?
What is the 'Deployment Rework Rate' from the 2024 DORA reports?
What is the difference between availability and reliability, and why does the distinction matter operationally?
Version Control & Branching
Can you explain Trunk-Based Development vs. GitFlow, and when would you use one over the other?
What are the trade-offs of a Mono-repo vs. Multi-repo strategy for CI/CD pipelines?
What is "Trunk-Based Development," and how does it facilitate Continuous Integration?
What role does version control play as the single source of truth in a DevOps workflow?
Explain the 'Test Pyramid' and its role in a CI pipeline.
Explain the definitive differences between Continuous Integration, Continuous Delivery, and Continuous Deployment.
Explain the typical anatomy of a CI/CD pipeline and what stages should exist and why.
How do you ensure a CI/CD pipeline remains "fast" without sacrificing reliability?
How do you handle a broken build in a shared pipeline, and what is the cultural protocol?
How do you identify and resolve bottlenecks in a CI/CD pipeline that has slowed down over time?
In a CI/CD context, what is the difference between a "Build Tool" and a "CI Server"?
What is a 'Build Artifact' and why is it important to make them immutable?
What is a 'Quality Gate' in a pipeline, and what types of checks belong there?
What is a smoke test, and where does it fit in the deployment process?
What is continuous testing, and how does it differ from simply running tests in CI?
What is the fundamental difference between Continuous Delivery and Continuous Deployment?
What is the role of an artifact repository in the delivery process, and why shouldn't we just deploy from source?
Why is Continuous Integration considered a developer practice rather than just a tool setup?
Why is the "Continuous Integration" part of the pipeline often considered the most difficult to maintain as a team grows?
Explain the "Cattle vs. Pets" analogy and how it changes the way you write software.
What are ephemeral (preview) environments, and how do they improve the development workflow?
What is "Immutable Infrastructure," and how does it differ from "Mutable Infrastructure"?
What is Configuration Drift, and how do you prevent or detect it?
What is the core philosophy behind "Infrastructure as Code" (IaC)?
What is the difference between configuration management and provisioning in infrastructure automation?
What is the difference between Declarative and Imperative Infrastructure as Code?
Why is environment parity (dev/staging/prod) important, and how do you achieve it?
Explain the CALMS framework and why each pillar is necessary for a successful DevOps transition.
How do you define 'Shared Ownership' between Dev and Ops teams?
How do you define a Blameless Postmortem, and why is it critical for a DevOps culture?
How does DevOps help in breaking down "silos" between development, QA, and operations?
What are the "Three Ways" of DevOps as described in The Phoenix Project?
What is 'Platform Engineering' and how does it differ from traditional DevOps?
What is Conway's Law, and how does it influence the way DevOps teams are structured?
What is DevOps to you, and how does it differ from just "automating things"?
What is DevOps to you, and how does it differ from traditional IT or Agile?
What is the 'Andon Cord' concept, and how does it apply to stopping the line when a build breaks?
What is the difference between DevOps and SRE?
Reliability & Incident Response
Explain the concept of "Mean Time to Recovery" (MTTR) and why it is often more important than "Mean Time Between Failures" (MTBF).
How do you define "Toil" in an SRE context, and why is it important to minimize it?
How does an on-call rotation work, and what practices keep it sustainable for a team?
How would you describe a typical incident management process, including severity levels and escalation?
What are RTO and RPO, and how do they shape a disaster recovery strategy?
What is "Chaos Engineering," and what is the goal of injecting failure into a production system?
What is "Idempotency," and why is it a critical requirement for any automation script?
What is a runbook, and what role does it play in incident response?
What is graceful degradation, and how does it contribute to fault tolerance?
What is the circuit breaker pattern, and why is it relevant to operating resilient services?
What is the purpose of readiness and liveness health checks in a deployed service?
Deployment & Release Strategies
Explain the difference between Blue-Green and Canary deployments and when you would use one over the other.
How do you achieve a zero-downtime release for a stateful application?
How do you handle database schema migrations in a zero-downtime deployment environment?
What are 'Feature Flags' and how do they decouple deployment from release?
What are the trade-offs of using Feature Flags (Feature Toggles) for releases?
What criteria would you use to trigger an automated rollback during a deployment?
What is 'Dark Launching' and how does it differ from a Canary release?
What is 'Progressive Delivery,' and how do feature flags enable it?
What is "Backward Compatibility" in the context of microservices deployment, and why is it mandatory for DevOps?
What is "Dark Launching," and when would you use it?
What is a Rolling Update, and what are its potential risks compared to Blue-Green?
What is A/B testing as a release strategy, and how does it differ from canary deployment?
What is shadow deployment (traffic mirroring), and when would you use it?
What is the difference between deploying and releasing, and why is decoupling them valuable?
When a deployment fails, what are the pros and cons of "Rolling Back" versus "Rolling Forward"?
When would you choose a Push-based vs. a Pull-based (GitOps) deployment model?
How do you approach secrets rotation as an ongoing practice rather than a one-time setup?
How do you manage Secrets (API keys, passwords) in a DevOps environment without hardcoding them?
How does the 'Twelve-Factor App' methodology relate to modern DevOps practices?
How should a "12-Factor App" handle environment-specific configurations?
What is "GitOps," and how does it differ from traditional CI/CD?
What is Policy as Code, and how does it support compliance in a DevOps pipeline?
How do you implement the "Principle of Least Privilege" within a CI/CD pipeline?
What does "DevSecOps" mean in practice, and how does it change the developer's responsibility?
What does Security as Code mean in a modern pipeline?
What is "Software Composition Analysis" (SCA), and where does it fit in the pipeline?
What is Software Supply Chain Security, and why is it a DevOps concern?
Where in the CI/CD pipeline should security scanning (SAST/DAST) occur, and why?
How do you think about cost management (FinOps) as part of DevOps operations?
How does capacity planning fit into an SRE/DevOps practice?
What is an Internal Developer Platform, and how does self-service infrastructure help delivery?
What is autoscaling, and what signals typically drive scaling decisions?
What is the difference between horizontal and vertical scaling, and when would you choose each?
Ci Cd Pipeline Design & Testing
How would you design a CI/CD pipeline for a monorepo with multiple services to avoid full rebuilds on every commit?
What is a 'Flaky Test' and how does it undermine DevOps culture?
What are Work-In-Progress (WIP) limits, and how do they improve flow in a delivery pipeline?
What does 'feedback loops' mean in the context of DevOps, and how do you shorten them?
What does it mean to "Shift Left" in a delivery pipeline, and what are the benefits?
What is "Value Stream Mapping," and how can a developer use it to identify bottlenecks?
Why is 'automating everything' not always the right answer, and how do you decide what to automate?
Why is Lead Time for Changes a better metric than Lines of Code?
Why is reducing batch size important in a DevOps delivery workflow?