Cypress Interview Questions and Answers

Sample questions

A few questions from each level with the correct answer and an explanation.

Cypress · Junior

1. Where do Cypress tests run?
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   Correct answer: Inside the browser, next to the app under test

   Cypress runs test code in the same browser run loop as the app, with a Node.js process alongside for tasks like files and network proxying. That's why it can read app state directly.

2. Which command opens the interactive Cypress app?
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   Correct answer: npx cypress open

   cypress open launches the app where you pick a browser and spec and watch tests run. cypress run runs tests headlessly, as in CI.

3. Which command runs all Cypress tests headlessly, e.g. in CI?
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   Correct answer: npx cypress run

   cypress run runs every spec in the terminal, records failure screenshots, and returns a non-zero exit code on failures.

4. Where is the main Cypress configuration usually defined?
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   Correct answer: In cypress.config.ts or cypress.config.js

   The config file sets baseUrl, spec patterns, viewport, timeouts, retries and Node event handlers via defineConfig.

Cypress · Middle

1. In Cypress 12+, what is the difference between queries and action commands?
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   Correct answer: Queries like get are retried; actions like click run once

   Queries re-run until assertions pass. Actions such as .click() or .type() aren't retried, though they wait for actionability first.

2. In cy.get('.list').find('li').should('have.length', 3), what is retried?
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   Correct answer: The whole chain of queries before the assertion

   Since Cypress 12, a failing assertion re-runs the chain of linked queries, so newly rendered elements are found.

3. What does .its('length') do?
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   Correct answer: Gets a property of the subject, with retrying

   .its() is a query, so cy.get('li').its('length').should('be.gt', 2) retries. .invoke() calls a method on the subject.

4. How do you check the body a form sends to the API?
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   Correct answer: Intercept it and assert interception.request.body

   This catches frontend bugs like wrong field names or types that a stubbed backend would accept silently.

Cypress · Senior

1. What is the main architectural trade-off of Cypress running inside the browser?
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   Correct answer: Direct access to the app, but limits like one tab and same-origin rules

   Running in the browser gives time travel, app access and reliable waits. The cost is single-tab control, origin limits and JavaScript-only tests.

2. When would you choose Cypress over Playwright for a team?
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   Correct answer: When the team values its interactive runner and the app fits its limits

   Cypress shines for single-app JS teams wanting fast feedback in the app runner. Multi-tab, multi-origin or multi-language needs favour Playwright.

3. Why does Cypress need cy.origin for SSO flows while Playwright doesn't?
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   Correct answer: Cypress runs inside one origin's page and must switch context explicitly

   Playwright drives the browser from outside, so origins don't matter. Cypress runs in the page, so other origins need a separate execution context.

4. What is the most common root cause of flaky Cypress tests in large suites?
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   Correct answer: Shared state and timing assumptions, like fixed waits or leaked data

   Most flakes trace to tests depending on each other, on real timing, or on shared backend data. Fix the cause; retries only hide it.