SQA Interview Questions
Common software quality assurance interview questions with clear, concise answers.
SQA interview questions
These questions come up in junior and mid-level QA interviews. Answer with a definition and a short real example — that's what interviewers listen for.
1. What is the difference between QA, QC and testing?
QA is process-focused and preventive — reviews, standards, Definition of Done. QC is product-focused and detective — inspecting what was built. Testing is the activity of executing software to find defects, and is part of QC.
2. Verification vs validation?
Verification asks "are we building it right?" (reviews, walkthroughs, static checks against the spec). Validation asks "are we building the right thing?" (running the software against real user needs, UAT).
3. What are the phases of the STLC?
Requirement analysis, test planning, test case design, environment setup, test execution and test closure. Each has entry and exit criteria.
4. What are entry and exit criteria? Give an example.
Conditions to start and finish a phase. Entry for execution: build deployed, smoke test passed, test cases reviewed. Exit: all critical tests passed, no open Critical/High bugs, product owner sign-off.
5. Name the seven testing principles.
Testing shows presence of defects; exhaustive testing is impossible; early testing; defect clustering; pesticide paradox; testing is context-dependent; absence-of-errors fallacy.
6. What is the difference between severity and priority?
Severity is the technical impact of a defect; priority is how urgently it should be fixed. A typo in the company name on the homepage is low severity but high priority; a crash in a rarely used admin report can be high severity but lower priority.
7. Explain the test pyramid.
Many fast unit tests at the base, fewer integration/API tests in the middle, and a small number of slow end-to-end UI tests at the top. It keeps suites fast and reliable.
8. What is risk-based testing?
Prioritising testing by likelihood × impact of failure, so the riskiest features (payments, data, security) get the deepest testing when time is limited.
9. What is a test plan and what does it contain?
A release-level document covering scope, out-of-scope items, approach, environments, entry/exit criteria, schedule, responsibilities, risks and deliverables.
10. What is a Requirements Traceability Matrix?
A table mapping each requirement to its test cases (and their status), proving coverage and showing which tests are affected when a requirement changes.
11. What is defect leakage?
The percentage of defects found in production out of all defects found. It measures how well testing protects users — lower is better.
12. What is shift-left testing?
Moving testing earlier: reviewing requirements, unit tests and TDD, automated checks on every pull request. Defects found earlier are cheaper to fix.
13. Functional vs non-functional testing?
Functional testing checks what the system does (features against requirements). Non-functional testing checks how well it does it — performance, security, usability, accessibility, compatibility.
14. What is UAT?
User Acceptance Testing — business users or the product owner confirm the system supports real workflows and is ready to release.
15. When would you stop testing?
When exit criteria are met: planned tests executed, critical tests passing, no open high-severity defects, risk accepted by stakeholders — or when the deadline forces a decision, in which case you report the remaining risk clearly.
16. A release is tomorrow and you found a critical bug today. What do you do?
Report it immediately with clear reproduction steps and impact, inform the product owner and lead, and help assess options — fix and retest, disable the feature behind a flag, or delay. The decision belongs to the stakeholders; your job is to make the risk clear.
17. How do you test when requirements are unclear?
Ask questions early, write down assumptions and get them confirmed, use exploratory testing and comparable products as oracles, and turn the answers into acceptance criteria.
18. What makes a good QA engineer?
Curiosity, attention to detail, clear communication, understanding of the user and the business, and enough technical skill to automate and read code. Good testers prevent bugs, not just find them.