DOL Technical Expertise 2 — Questions and Answers
Question 1: A DevOps team is experiencing high mean time to recovery (MTTR) after production incidents. Which technical practice most directly reduces MTTR?
- Increasing sprint velocity
- Implementing feature flags for instant rollback (Correct answer)
- Adding more manual approval gates
- Expanding the QA team headcount
Correct answer: Implementing feature flags for instant rollback
Feature flags allow teams to instantly disable a problematic feature in production without a full deployment, directly reducing MTTR.
Question 2: Which container orchestration concept ensures that a specified number of pod replicas are always running in Kubernetes?
- StatefulSet
- DaemonSet
- ReplicaSet (Correct answer)
- ConfigMap
Correct answer: ReplicaSet
A ReplicaSet maintains a stable set of replica pods running at any given time, automatically replacing pods that fail or are deleted.
Question 3: A DevOps Leader wants to implement shift-left security. Which practice best embodies this approach?
- Running penetration tests after every major release
- Integrating SAST tools directly into developer IDEs and CI pipelines (Correct answer)
- Hiring a dedicated security team to review code before deployment
- Performing security audits quarterly
Correct answer: Integrating SAST tools directly into developer IDEs and CI pipelines
Integrating SAST (Static Application Security Testing) into IDEs and CI pipelines catches vulnerabilities at the earliest possible stage of development.
Question 4: What is the primary purpose of a service mesh in a microservices architecture?
- Storing service configuration in a centralized registry
- Managing inter-service communication, observability, and security policies (Correct answer)
- Orchestrating container deployments across multiple clusters
- Providing a shared database layer for microservices
Correct answer: Managing inter-service communication, observability, and security policies
A service mesh handles service-to-service communication concerns like load balancing, mTLS, retries, and distributed tracing transparently.
Question 5: Which metric best indicates the effectiveness of a DevOps team's automated testing strategy?
- Number of test cases written per sprint
- Percentage of defects caught in production vs. pre-production (Correct answer)
- Total CI pipeline execution time
- Number of test engineers on the team
Correct answer: Percentage of defects caught in production vs. pre-production
The ratio of defects caught pre-production versus production directly measures how well automated tests prevent regressions from reaching users.
Question 6: A team uses blue-green deployment. What is the key infrastructure requirement for this strategy?
- A single environment with automated rollback scripts
- Two identical production environments with a traffic-switching mechanism (Correct answer)
- A canary environment receiving 5% of traffic
- Multiple feature branches deployed simultaneously
Correct answer: Two identical production environments with a traffic-switching mechanism
Blue-green deployment requires two identical environments where traffic is switched instantly from the old (blue) to the new (green) version.
Question 7: When implementing GitOps, which component acts as the single source of truth for the desired state of infrastructure?
- The CI/CD pipeline configuration
- A Git repository containing declarative configuration files (Correct answer)
- The current state of the Kubernetes cluster
- An ITSM ticketing system
Correct answer: A Git repository containing declarative configuration files
GitOps uses a Git repository as the authoritative source for infrastructure and application configuration, with automated reconciliation to match the live environment.
DOL Technical Expertise 2
A DevOps team is experiencing high mean time to recovery (MTTR) after production incidents.
Which technical practice most directly reduces MTTR?