Software Testing Interview Questions for E-commerce &amp; consumer tech Companies

Automation Basics for Manual TestersEasy

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Add, remove, update quantity, price and tax calculation, coupon codes, stock limits, cart persistence after login and checkout navigation.

What is a bug bash and how do you run one?

Bug Life Cycle and JiraMedium

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A bug bash is a short, time-boxed session where people from across the team, including developers, product and support, test the product together to find as many issues as possible before a release. To run one, share a build, scope and test accounts, assign focus areas, give a simple bug template and a shared board, then triage findings at the end. It brings fresh eyes and finds usability issues formal tests miss.

How do you do cross-browser testing and choose which browsers to cover?

Testing TypesMedium

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Use analytics to pick browsers and versions that most real users have, plus the ones listed in the requirement, usually the latest two versions of major desktop and mobile browsers. Run the main flows on each and check layout, fonts, forms, date pickers, file upload and JavaScript errors in the console. Use responsive mode for screen sizes, and real devices or a cloud device lab for mobile browsers.

Why are hard-coded sleeps bad in automated tests?

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A fixed sleep, such as waiting five seconds, is either too long, which makes the suite slow when the page loads in one second, or too short, which makes the test fail when the server is slow. Both waste time and cause flaky results. Instead, wait for a real condition: an element to appear, a network response to finish or a loading spinner to disappear. Modern tools do much of this automatically.

What is defect clustering?

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The observation that a small number of modules contain most defects, so testing should focus on those areas.

SQL: find duplicate emails.

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SELECT email, COUNT(*) FROM users GROUP BY email HAVING COUNT(*) > 1;

How do you test a mobile app when the device storage is almost full?

Mobile TestingMedium

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Fill the device storage close to the limit, then install or update the app and confirm a clear message if it cannot proceed. Inside the app, try downloads, photo capture, caching and saving drafts. The app should show a helpful error, not crash or corrupt data. Also check what happens to the local database when a write fails, and whether the app recovers after space is freed.

Write test cases for a signup form.

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Mandatory fields, email format, password rules, duplicate email, terms checkbox, captcha, confirmation email and field length limits.

A manager wants to cut QA time in half. How do you explain the value of testing?

Manual Testing BasicsHard

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Use data, not opinion. Show defects caught before release by severity, production incidents and their cost, and defect leakage trends. Explain what risk increases if testing is cut, then offer options: risk-based testing of critical flows, more automation for regression, and developers owning unit tests. Agree on which risks the business accepts in writing. This turns the discussion into a trade-off decision instead of a conflict.

Release is tomorrow and you can't test everything. What now?

STLC and Test PlanningHard

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Risk-based testing: cover critical user flows, recent changes and high-defect areas first. Clearly communicate the untested risks and get stakeholder sign-off.

What is compatibility testing?

Testing TypesMedium

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Checking the application works across browsers, devices, operating systems, screen sizes and network conditions.

What is test monitoring and control?

STLC and Test PlanningMedium

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Test monitoring compares actual testing progress with the plan, using metrics like test cases executed, pass rate, open defects and effort spent. Test control is the action taken when monitoring shows a gap, such as re-prioritising tests, adding testers, changing the schedule or tightening entry criteria. For example, if half the time has passed but only a quarter of cases are executed, the lead must act and inform stakeholders.

How would you choose a device matrix for testing an app in India?

Mobile TestingHard

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Use the app's analytics, or market data if it is a new app, to find the top devices, OS versions and screen sizes. In India, cover a strong share of budget and mid-range Android phones with low RAM, a few manufacturers' custom Android skins, the two or three latest Android versions, and recent iPhones if iOS is supported. Add a tablet if relevant. Review the matrix each quarter and use a cloud device lab for wider coverage.

What is installation and upgrade testing?

Testing TypesMedium

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Installation testing checks that software installs correctly on supported systems: fresh install, custom paths, low disk space, missing prerequisites and clean uninstall. Upgrade testing checks moving from an older version to the new one: user data and settings must be kept, database migrations must run, and the app must work after the upgrade. Also test skipping versions, such as 1.2 to 1.5, and what happens if the upgrade is interrupted.

How do you test form accessibility, including labels and error messages?

Accessibility & Usability TestingMedium

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Check that every field has a visible label tied to it, so clicking the label focuses the field and a screen reader announces it. Required fields must be indicated in text, not only by colour or an asterisk without explanation. Submit with errors and check that messages are specific, appear next to the field, are announced by the screen reader and focus moves to the first error. Also check autocomplete for name, email and address.

The sprint ends tomorrow and two stories are still in testing. What do you do?

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Tell the Scrum Master and product owner today, not at the review. Focus testing on the acceptance criteria and the riskiest paths of the story with the most value, and ask a developer to help with test data or simple checks. If a story cannot be finished with quality, it should be carried over, not marked done with untested parts. Raise the cause in the retrospective, such as late handover.

What is a test oracle?

Automation Basics for Manual TestersHard

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A test oracle is the source you use to decide whether a test result is correct, that is, the expected result. It can be a requirement document, a user story, an older version of the system, a calculation in a spreadsheet, a domain expert or common sense. For example, when testing a tax calculator, the official tax slab table is the oracle. Without a reliable oracle, you cannot say a test passed or failed.

What is contract testing?

Testing TypesHard

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Contract testing checks that a service provider and its consumers agree on the API format, such as request fields, response fields and status codes, without running a full end-to-end environment. The consumer defines what it expects, and the provider's build verifies it still meets that contract. It catches breaking changes early in microservice systems, where full integration environments are slow and fragile.

What is a flaky test and what usually causes it?

Automation Basics for Manual TestersMedium

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A flaky test passes and fails on the same code without any change. Common causes are timing problems such as fixed sleeps or missing waits, tests depending on each other or on shared data, unstable locators, animations, third-party services, test order in parallel runs and environment issues like slow servers. Flaky tests destroy trust in the suite, so teams quarantine them, find the root cause and fix it rather than adding retries forever.

Your team wants to use an AI tool to generate test cases and automation scripts. What benefits and risks do you point out?

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AI assistants can draft test cases from requirements, suggest edge cases, generate first versions of scripts and test data, and some tools self-heal locators when the page changes. Risks are confident but wrong output, tests that assert the wrong behaviour, hidden locator changes that mask real bugs and leaking confidential data into external tools. Treat AI output like a junior's draft: review it, run it and keep human judgement on what matters.

What is the V-model?

Automation Basics for Manual TestersHard

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A development model where each development phase has a matching testing phase, such as requirements with acceptance tests and design with integration tests.

How do you decide which automated tests run on every pull request and which run nightly?

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Pull request checks must be fast, usually under ten to fifteen minutes, and highly reliable, so they include unit tests, API tests for changed services and a small UI smoke set of critical flows. The full UI regression, cross-browser runs, long data-driven suites and performance checks run nightly or before release. Tag tests by suite, measure run times and flakiness, and move tests between suites based on value and speed.

Your test repository has many duplicate and outdated test cases. How do you clean it up?

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Export the cases and group them by module and requirement. Mark duplicates, merge them into one well-written case, and retire cases for removed features. Check which cases have not been executed or failed in months and confirm whether they are still valid. Link the remaining cases to requirements so gaps are visible. Do it module by module with peer review, and set a rule that every story update also updates its test cases.

Product is running an A/B test on the checkout button. What does QA need to verify?

Testing TypesMedium

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QA does not decide which version wins, but makes sure the experiment is trustworthy. Verify both variants work end to end, users are split in the agreed ratio, each user sees the same variant consistently across sessions, and analytics events fire correctly for each group. Also check that turning the experiment off returns everyone to the default. A broken tracking event can make the whole experiment's result wrong.

Write test cases for an ATM withdrawal.

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Valid card and PIN, wrong PIN, three failed attempts, amount above balance, amount above daily limit, invalid denomination, machine out of cash, network failure and receipt printing.

Write test cases for a one-to-one chat feature.

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Send and receive text messages and check order and timestamps. Test sent, delivered and read status. Send emojis, long messages, links and attachments within and over the size limit. Check messages sent while offline are queued and delivered on reconnect. Verify blocking a user stops messages. Test notifications when the app is in background. Check chat history after reinstall or on a second device, and that deleted messages disappear for both users if supported.

What is mobile app testing and what extra checks does it need?

Mobile TestingMedium

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Test on real devices and OS versions, interrupts such as calls, battery, network changes, gestures, permissions and app store guidelines.

A page loads slowly only for some users. How do you investigate as a manual tester?

Performance and Security BasicsMedium

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Collect details from affected users: location, device, browser, network and time. Try to reproduce with similar conditions using browser network throttling. Use the browser developer tools network tab to find slow requests, large files or failing calls, and compare with a fast user. Check whether those users have more data, like a long order history. Share the slow request, timing and conditions in the bug for the developers.

What is a blocker bug?

Bug Life Cycle and JiraMedium

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A defect that stops testing or release of a feature because no workaround exists, so it is highest priority.

How do you handle a product owner who keeps adding scope in the middle of a sprint?

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Model answer: Situation: our product owner added two small changes to a story mid-sprint, which pushed testing to the last day. Task: protect quality without being rigid. Action: I showed the extra test effort in stand-up and asked the Scrum Master to help decide what to swap out. Result: one change moved to the next sprint, and the team agreed new requests go through the backlog.

What do testers look for during a requirement review?

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Check that each requirement is clear, complete, consistent and testable. Look for vague words like fast or user-friendly, missing error handling, undefined limits, conflicting rules and missing roles or states. For each requirement ask how you would test it and what the expected result is. Record questions in a review log and get answers from the business analyst before writing test cases, so ambiguity does not turn into defects later.

What is error guessing?

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Using experience to guess where defects likely hide, such as empty fields, special characters or unexpected sequences, and designing tests for them.

What are transaction isolation levels and what is a dirty read?

Database TestingHard

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Isolation levels control how much one transaction can see of another's uncommitted work. Common levels are Read Uncommitted, Read Committed, Repeatable Read and Serializable. A dirty read is reading data another transaction changed but has not committed; if it rolls back, you acted on data that never existed. Testers check isolation using two database sessions: update without committing in one and query in the other to see what is visible.

How do you test API error handling for invalid input?

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Send requests with missing required fields, wrong data types, values beyond limits, invalid formats such as a bad email, unknown fields and an empty or malformed JSON body. The API should return a 4xx code such as 400 or 422, a clear error message that names the field, and no stack trace or database details. Also check that nothing was partly saved in the database after the failed request.

Explain SQL joins briefly.

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INNER returns matching rows, LEFT keeps all left rows, RIGHT keeps all right rows and FULL keeps all rows from both tables.

A requirement says the page should load fast. How do you turn it into a test case?

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The word fast is not testable, so ask the product owner for a measurable target, for example the page loads within 3 seconds on a 4G network for 95 percent of requests. Agree on the conditions: device, network, data size and whether it is first load or cached. Then write the test with those conditions and expected time. Record the agreed number in the story so the expected result is not open to opinion.

What is the difference between a walkthrough and an inspection?