🧪 Software Testing Interview Questions and Answers (2025)
Basic Level Questions
What is software testing? ▶
Software testing is the process of evaluating a system or its components to find whether it meets the specified requirements and identify defects.
What are the different levels of testing? ▶
Common levels are Unit Testing, Integration Testing, System Testing, and Acceptance Testing.
What is the difference between verification and validation? ▶
Verification checks if the product is built correctly (according to specifications); validation checks if the right product is built (meets user needs).
What is a defect or bug? ▶
A defect or bug is a flaw or error in software that causes it to produce incorrect or unexpected results or behave in unintended ways.
What is the difference between functional and non-functional testing? ▶
Functional testing verifies specific functions or features work as expected; non-functional testing checks performance, usability, security, and other system attributes.
What is regression testing? ▶
Regression testing verifies that recent code changes have not adversely affected existing functionality.
What is test automation? ▶
Test automation uses software tools to execute pre-scripted tests automatically and compare results.
What is a test case? ▶
A test case defines a set of conditions, inputs, steps, and expected results used to verify a particular feature or functionality.
What is the difference between severity and priority in bugs? ▶
Severity indicates the impact of a bug on the system; priority determines how soon the bug should be fixed.
What is a test plan? ▶
A test plan is a detailed document outlining the scope, approach, resources, schedule, and activities planned for testing.
Intermediate Level Questions
What is the difference between black-box and white-box testing? ▶
Black-box testing focuses on testing software functionality without knowledge of internal code; white-box testing involves testing internal structures or workings of an application.
What are smoke and sanity testing? ▶
Smoke testing quickly checks basic functionality of a build; sanity testing verifies specific functionality after minor changes.
What is boundary value analysis? ▶
A test design technique focusing on values at the edges of input ranges to detect errors at boundaries.
Explain equivalence partitioning. ▶
Equivalence partitioning divides input data into partitions of equivalent values to test one representative from each partition.
What is continuous integration (CI) and its importance in testing? ▶
CI is the practice of automatically integrating and testing code frequently to catch issues early and improve software quality.
What is load testing? ▶
Load testing evaluates system performance under expected user loads to ensure stability and responsiveness.
What is stress testing? ▶
Stress testing checks system behavior under extreme or peak load conditions to identify breaking points.
How do you prioritize test cases? ▶
Prioritization is based on critical functionalities, risk areas, customer impact, and likelihood of defect occurrence.
What is test coverage? ▶
Test coverage measures the extent to which the source code or requirements are tested by a set of test cases.
What is defect life cycle? ▶
Defect life cycle describes the stages a defect goes through from discovery to closure, including states like New, Assigned, Fixed, Retested, and Closed.
Advanced Level Questions
What are the challenges of test automation? ▶
Challenges include selecting the right tools, maintaining test scripts with changing UI, test data management, and integrating with CI/CD pipelines efficiently.
What is a test strategy and how is it different from a test plan? ▶
Test strategy is a high-level document outlining the testing approach and standards; test plan is more detailed including scope, schedule, resources, and specific activities.
How do you measure the effectiveness of testing? ▶
By analyzing defect detection rate, test coverage, test execution metrics, user feedback, and post-release defect counts.
Explain risk-based testing. ▶
Risk-based testing focuses testing efforts on features and functionalities with higher risks of failure or impact.
How do you maintain and scale an automated test suite? ▶
By regularly reviewing and refactoring tests, modularizing test scripts, managing test data effectively, and using parallel execution and cloud testing platforms.
What are some common tools used in automation testing? ▶
Common tools include Selenium, JUnit, TestNG, Cucumber, Appium, Jenkins for CI/CD, and Postman for API testing.
Explain the concept of shift-left testing. ▶
Shift-left testing involves integrating testing early in the development lifecycle to detect defects sooner and reduce costs.
How do you test for security vulnerabilities? ▶
By conducting vulnerability scans, penetration testing, input validation testing, and reviewing authentication and authorization mechanisms.
What is test data management and why is it important? ▶
Test data management involves creating and maintaining data sets used for testing; it ensures test relevance, privacy compliance, and repeatability.
Explain performance testing and types. ▶
Performance testing measures system responsiveness and stability; types include load testing, stress testing, endurance testing, and spike testing.