Question 1

What is CI/CD and where does test automation fit?

Accepted Answer

Continuous Integration merges and validates code frequently with automated builds and tests, while Continuous Delivery/Deployment automatically releases validated builds. Automated tests are the quality gates that decide whether a change can move to the next stage.

Question 2

What Git commands do you use daily as an automation engineer?

Accepted Answer

clone, pull, checkout/switch, add, commit, push, status, log and diff cover most work. A typical flow is creating a feature branch, committing tests, pushing, and opening a pull request.

Question 3

What branching strategies have you worked with?

Accepted Answer

Common strategies are GitFlow (develop, feature, release, hotfix branches), GitHub Flow (short-lived feature branches off main), and trunk-based development. Most modern teams use GitHub Flow or trunk-based with feature flags.

Question 4

What is the difference between git merge and git rebase?

Accepted Answer

Merge combines branches with a merge commit and preserves history as it happened. Rebase replays your commits on top of another branch, producing a linear history but rewriting commit hashes.

Question 5

How do you resolve a merge conflict?

Accepted Answer

Git marks conflicting sections with <<<<<<<, ======= and >>>>>>> markers. Edit the file to keep the correct code, remove the markers, stage the file, and complete the merge or rebase.

Question 6

What stages are in a typical pipeline and which tests run where?

Accepted Answer

A typical pipeline is build, lint and unit tests, API/integration tests, deploy to staging, E2E/smoke tests, then deploy to production with post-deploy smoke checks. Faster, cheaper tests run earlier to fail fast.

Question 7

How do you trigger test pipelines?

Accepted Answer

Pipelines can be triggered on push, pull request, a schedule (cron), manually, or by another workflow or deployment. In GitHub Actions these are defined under the on key.

Question 8

Write a GitHub Actions workflow to run Playwright tests.

Accepted Answer

Check out code, set up Node 20+, install dependencies with npm ci, install browsers with npx playwright install --with-deps, run tests, and upload the HTML report as an artifact even on failure.

Question 9

Write a Jenkins declarative pipeline for running tests.

Accepted Answer

A Jenkinsfile defines agent, stages and post actions. Tests run in a stage, JUnit results are published with the junit step, and reports are archived in the post always block.

Question 10

Why and how do you run tests in Docker?

Accepted Answer

Docker gives a consistent environment with pinned OS, Node and browser versions, eliminating works-on-my-machine issues. Use official images like the Playwright or Cypress images, or build your own Dockerfile.

Question 11

How do you speed up a slow test suite in CI with sharding?

Accepted Answer

Split tests across multiple machines with a matrix and the framework's shard option, e.g. --shard=1/4 in Playwright. Each shard uploads a blob report, and a final job merges them into one HTML report.

Question 12

How do you publish test reports and artifacts in CI?

Accepted Answer

Generate machine-readable (JUnit XML) and human-readable (HTML, Allure) reports, then upload them as pipeline artifacts. Traces, screenshots and videos on failure make debugging CI failures possible.

Question 13

How do you manage secrets like passwords and API tokens in pipelines?

Accepted Answer

Store them in the CI secret store (GitHub Secrets, Jenkins Credentials, Vault) and inject them as environment variables at runtime. Never commit them to the repo or print them in logs.

Question 14

How do you run tests across browsers or environments in CI?

Accepted Answer

Use a matrix strategy to create one job per combination of browser, OS or environment. Each job passes its matrix values to the test command, e.g. Playwright's --project flag.

Question 15

When would you use git revert, git reset and git cherry-pick?

Accepted Answer

revert creates a new commit that undoes a previous one and is safe on shared branches. reset moves the branch pointer and can discard commits, so use it only on local work. cherry-pick copies a specific commit onto the current branch.

Question 16

What are quality gates and how do you enforce them?

Accepted Answer

Quality gates are automated pass/fail criteria a change must meet before merging or deploying, such as all tests passing, coverage thresholds, lint, and static analysis. They are enforced via required status checks and branch protection rules.

Question 17

How do you handle flaky tests in CI?

Accepted Answer

Detect flakiness with retries and reporting, quarantine flaky tests so they do not block merges, and fix root causes like poor waits, shared state or test data collisions. Retries are a signal, not a solution.

Question 18

How do you make CI test runs faster?

Accepted Answer

Cache dependencies and browser binaries, shard and parallelise tests, run only affected tests on PRs, and reuse authentication state instead of logging in through the UI each test.

Question 19

How do you spin up the application and dependencies for tests in CI?

Accepted Answer

Use service containers or docker compose to start databases and backends, then start the app and wait for a health check before running tests. Playwright's webServer config can start and wait for the app automatically.

Question 20

How do you notify the team about test failures and track results over time?

Accepted Answer

Send notifications to Slack or Teams on failure, post a summary to the PR or job summary, and push results to a dashboard like Allure TestOps or ReportPortal for trends.

Question 21

What does git stash do and when do you use it?

Accepted Answer

git stash saves uncommitted changes to a stack and cleans the working tree, so I can switch branches or pull without committing half-done work. git stash pop reapplies and removes the latest stash, while apply keeps it.

Question 22

What is the difference between git fetch and git pull?

Accepted Answer

git fetch downloads new commits and refs from the remote without changing your working branch. git pull is fetch followed by a merge (or rebase, if configured) into your current branch.

Question 23

Explain git reset --soft, --mixed and --hard.

Accepted Answer

All three move the branch pointer to a given commit. --soft keeps changes staged, --mixed (the default) keeps them in the working tree but unstaged, and --hard discards them entirely.

Question 24

How do you recover a commit you lost after a reset or a deleted branch?

Accepted Answer

git reflog lists where HEAD has pointed recently, including commits no longer on any branch. I find the commit hash there and create a branch or reset to it.

Question 25

How and why do you squash commits?

Accepted Answer

Squashing combines several small work-in-progress commits into one meaningful commit, keeping main's history clean. Most teams use 'Squash and merge' on the pull request; locally it can be done with an interactive rebase.

Question 26

What should a test automation repo's .gitignore contain?

Accepted Answer

Build output, dependencies and generated reports should be ignored: node_modules, target or build folders, test-results, reports, screenshots, videos and local .env files. Lock files should be committed, not ignored.

Question 27

What does a good pull request process look like for test code?

Accepted Answer

Small focused PRs from a feature branch, a clear description with the ticket link, CI checks that run the affected tests, and at least one reviewer. Branch protection on main enforces passing checks and approvals before merge.

Question 28

Explain the structure of a GitHub Actions workflow.

Accepted Answer

A workflow is a YAML file in .github/workflows with on (triggers), jobs, and steps. Each job runs on a runner, and steps either run shell commands with run or use reusable actions with uses.

Question 29

How do you schedule a nightly run and allow manual runs with inputs in GitHub Actions?

Accepted Answer

Use on.schedule with a cron expression (in UTC) for nightly runs, and on.workflow_dispatch with inputs for manual runs. The inputs are read with the inputs context.

Question 30

How do you pass data between jobs in GitHub Actions?

Accepted Answer

Small values go through job outputs: a step writes to $GITHUB_OUTPUT, the job exposes it under outputs, and a dependent job reads it via needs.<job>.outputs. Files go through upload-artifact and download-artifact.

Question 31

What are reusable workflows and composite actions?

Accepted Answer

A reusable workflow is a whole workflow triggered with on.workflow_call and called from another workflow's job via uses. A composite action bundles several steps into one action used inside a job. Both remove copy-paste across repos.

Question 32

How do you cancel outdated pipeline runs when new commits are pushed?

Accepted Answer

In GitHub Actions, a concurrency group keyed on workflow and branch with cancel-in-progress: true cancels older runs. Jenkins has disableConcurrentBuilds(abortPrevious: true) for the same purpose.

Question 33

How do you require approval before running tests or deploying to production in GitHub Actions?

Accepted Answer

Define a GitHub environment such as production with required reviewers and environment-scoped secrets, then reference it with environment: in the job. The job pauses until an approved reviewer approves it.

Question 34

What is the difference between a Jenkins freestyle job and a pipeline?

Accepted Answer

Freestyle jobs are configured through the UI and are hard to version or review. Pipelines are defined as code in a Jenkinsfile stored in the repo, support stages, parallelism and conditions, and are the recommended approach.

Question 35

How do you run test suites in parallel in Jenkins?

Accepted Answer

In a declarative pipeline I put a parallel block inside a stage, with one nested stage per suite or browser, optionally on different agents. failFast true aborts the others if one fails.

Question 36

How do you use credentials securely in a Jenkins pipeline?

Accepted Answer

Store them in the Jenkins credentials store and bind them in the pipeline with withCredentials or the credentials() helper in environment. Jenkins masks the values in console logs.

Question 37

How do you add build parameters and choose agents in a Jenkinsfile?

Accepted Answer

The parameters directive defines inputs like choice or string, read via params.NAME. The agent directive picks where it runs: any, a label, or a Docker image.

Question 38

Write a Dockerfile to run your test suite.

Accepted Answer

Start from an official image with the runtime and browsers, copy dependency manifests first to use layer caching, install dependencies, then copy the source and set the test command.

Question 39

What is the difference between a Docker image and a container?

Accepted Answer

An image is a read-only template with the filesystem and config needed to run something. A container is a running (or stopped) instance of an image with its own writable layer.

Question 40

How do you run Selenium Grid with Docker Compose?

Accepted Answer

Define a selenium/hub service and browser node services that point to the hub via SE_EVENT_BUS environment variables, then run docker compose up. Tests use RemoteWebDriver against http://localhost:4444.

Question 41

How do you make tests wait until services in Docker Compose are ready?

Accepted Answer

Add a healthcheck to each dependency and use depends_on with condition: service_healthy so the test container starts only when they are ready. depends_on alone only waits for the container to start, not for the app to be ready.

Question 42

Explain Pods, Deployments and Services in Kubernetes.

Accepted Answer

A Pod is the smallest unit, one or more containers sharing network and storage. A Deployment manages replicated Pods and rolling updates, and a Service gives a stable network name and load balancing in front of those Pods.

Question 43

How would you run automated tests inside Kubernetes?

Accepted Answer

Package tests as a container image and run them as a Kubernetes Job, optionally an Indexed Job where each pod runs one shard. Results are pushed to object storage or a results service because pods are ephemeral.

Question 44

Which kubectl commands help you debug an environment where tests fail?

Accepted Answer

kubectl get pods to check status and restarts, kubectl describe pod for events like image pull or OOM errors, kubectl logs (with --previous for crashed containers) for app logs, and kubectl port-forward to reach a service locally.

Question 45

How do you merge reports from sharded test runs?

Accepted Answer

Each shard uploads its raw results as an artifact, and a final job downloads them all and merges them. In Playwright I use the blob reporter on shards and npx playwright merge-reports to build one HTML report.

Question 46

Why is JUnit XML output important in CI?

Accepted Answer

JUnit XML is the common format almost every CI tool understands, so it lets Jenkins, GitLab, Azure DevOps or GitHub test reporters show pass/fail counts, trends and failed test details regardless of language.

Question 47

How do you cache dependencies and browsers in GitHub Actions?

Accepted Answer

setup-node, setup-java and setup-python have a built-in cache option keyed on the lock file. For other folders, such as Playwright browsers, actions/cache with a key including the tool version works.

Question 48

What are blue-green and canary deployments, and how do tests fit in?

Accepted Answer

Blue-green runs two identical environments and switches traffic to the new one after it passes smoke tests, allowing instant rollback. Canary sends a small percentage of traffic to the new version and widens it while metrics stay healthy.

Question 49

What is the difference between continuous delivery and continuous deployment?

Accepted Answer

In continuous delivery every change is automatically built, tested and kept releasable, but production release needs a manual approval. In continuous deployment, every change that passes the pipeline goes to production automatically.

Question 50

How would you find which commit introduced a regression using Git?

Accepted Answer

git bisect does a binary search through history: I mark a known bad and a known good commit, and Git checks out midpoints for me to test until it finds the first bad commit. With git bisect run and a test script, it is fully automated.

Interview Questions

01What is CI/CD and where does test automation fit?BeginnerCI/CD Fundamentals

02What Git commands do you use daily as an automation engineer?BeginnerGit

03What branching strategies have you worked with?BeginnerGit

04What is the difference between git merge and git rebase?BeginnerGit

05How do you resolve a merge conflict?BeginnerGit

06What stages are in a typical pipeline and which tests run where?BeginnerCI/CD Fundamentals

07How do you trigger test pipelines?BeginnerGitHub Actions

08Write a GitHub Actions workflow to run Playwright tests.IntermediateGitHub Actions

09Write a Jenkins declarative pipeline for running tests.IntermediateJenkins

10Why and how do you run tests in Docker?IntermediateDocker & Environments

11How do you speed up a slow test suite in CI with sharding?IntermediateGitHub Actions

12How do you publish test reports and artifacts in CI?IntermediateReporting & Quality Gates

13How do you manage secrets like passwords and API tokens in pipelines?IntermediateDocker & Environments

14How do you run tests across browsers or environments in CI?IntermediateGitHub Actions

15When would you use git revert, git reset and git cherry-pick?IntermediateGit