Software Testing Interview Questions (300+) Guide

How to Use This Guide

Questions are grouped by topic with counts. Learn the concept behind each group from the matching lesson, then answer aloud in 60 seconds with one example.

Manual Testing (100)

• What is testing? Why is it needed? Error vs defect vs failure?
• Explain STLC phases and entry/exit criteria with examples.
• Write test cases for login, lift, pen, ATM, WhatsApp.
• Severity vs priority with two real examples each way.
• What is RTM? Draw a mini matrix for checkout.

Selenium (50)

• WebDriver architecture; locators priority order.
• Absolute vs relative XPath; write 5 real XPaths.
• Handle dropdown, alert, frame, multi-window with code.
• Implicit vs explicit vs fluent waits; why sleep is banned.
• Explain your POM framework end to end.

API Testing (40)

• GET vs POST vs PUT vs PATCH; status code families.
• How do you test auth? 401 vs 403 with examples.
• Postman variables, scripts, Newman runs.
• Validate schema, pagination, rate limits.

Java + TestNG/JUnit (60)

• OOP pillars with test-framework examples.
• TestNG annotations order; groups; DataProvider; parallel runs.
• JUnit 5 lifecycle; parameterized tests; assertThrows.
• Mockito: @Mock vs @InjectMocks; when/verify; why mock?

SQL and Database (20)

• JOINs with an orders example; find orphans and duplicates.
• How do you verify an API write in the DB?
• Constraints, transactions, migration checks.

Performance, Agile, Scenario (40)

• Load vs stress vs endurance; p95 and throughput.
• Build a JMeter plan in 5 steps; interpret the report.
• Scrum ceremonies for testers; Definition of Done.
• Scenarios: payment deducted but order failed; OTP not received; site slow only on Mondays.

Key Points

• Always answer with concept plus example plus your project.
• End each answer with how you automated or prevented it.
• Keep a GitHub repo to show, not just tell.