Question 1

What is the difference between an explicit wait and a fixed sleep?

Accepted Answer

An explicit wait ends as soon as a condition is true; a sleep always waits the full time. Condition-based waiting is the single most important stability technique in test automation. 'Wait for what you expect, not for time' is the rule interviewers want to hear.

Question 2

Which locator is the most stable for a submit button over time?

Accepted Answer

A role or test-id locator, e.g. getByRole('button', { name: 'Save' }). Prefer locators tied to meaning: role + accessible name, label, or a dedicated data-testid. Avoid anything tied to layout or styling.

Question 3

Why must every automated test be able to run alone, in any order?

Accepted Answer

Because parallel runs and filtered runs change the order, so hidden dependencies cause random failures. Independent tests = each test creates its own starting state (usually in beforeEach). The practical check: run any single test alone, it must pass.

Question 4

A feature is used once a year, takes 2 minutes to check manually, and its UI changes often. Should you automate it?

Accepted Answer

No. The maintenance cost outweighs the value; keep it as a manual check. What to automate: stable, repeated, high-value flows (login, checkout, regression paths). What not to: rare, cheap-to-check, fast-changing scenarios.

Question 5

Your test clicks 'Delete' and then immediately asserts the row count dropped, but the app shows a confirm dialog first. The test fails. What is the actual bug?

Accepted Answer

The test does not follow the real user flow, it must confirm the dialog before asserting. When a test fails, first ask whether the test's assumptions match the real app flow. Many 'flaky' tests are simply wrong about what the app does.

Question 6

What makes a good automated regression suite?

Accepted Answer

Fast, reliable and focused on the flows that matter most to the business. Judge a regression suite by trust and signal: when it is green you feel safe to release, and when it is red there is a real problem.

QA Automation Engineer Interview Preparation

What is the difference between an explicit wait and a fixed sleep?

Full checkout flow

Search with no results