Top 29 Software Testing Interview Questions And Answers

Question 1

Name some performance testing steps

Accepted Answer

Some of the performance testing steps are:

* Identify the testing environment
* Identify performance metrics
* Plan and design performance tests
* Configure the test environment
* Implement your test design
* Execute tests
* Analyze, report, retest

Question 2

What is _Mocking_?

Accepted Answer

**Mocking** is primarily used in unit testing. An object under test may have dependencies on other (complex) objects. To isolate the behavior of the object you want to replace the other objects by mocks that simulate the behavior of the real objects. This is useful if the real objects are impractical to incorporate into the unit test.

In short, **mocking **is creating objects that simulate the behavior of real objects.

Question 3

How to unit test an object with _database_ queries?

Accepted Answer

* If your objects are tightly coupled to your data layer, it is difficult to do proper unit testing. Your objects should be _persistent ignorant_. You should have a _data access layer_, that you would make requests to, that would return objects. 
* Then _mock_ out your calls to the database. This way, you can leave that DB dependants part out of your unit tests, test them in isolation or write _integration tests_.

Question 4

What is Load Testing?

Accepted Answer

**Load testing** measures system performance as the workload increases. That workload could mean concurrent users or transactions.The system is monitored to measure response time and system staying power as workload increases. That workload falls within the parameters of normal working conditions.

Question 5

Name the difference between _Acceptance Test_ and _Functional Test_

Accepted Answer

* **Functional testing**: This is a _verification_ activity; _did we build a correctly working product?_ Does the software meet the business requirements? A functional test verifies that the product actually works as you (the developer) think it does.

* **Acceptance testing**: This is a _validation_ activity; _did we build the right thing?_ Is this what the customer really needs? Acceptance tests verify the product actually solves the problem it was made to solve. This can best be done by the user (customer), for instance performing his/her tasks that the software assists with.

Question 6

What is profiling?

Accepted Answer

**Profiling **measures how long various parts of the code take to run. Profilers are implemented a lot like debuggers too, except that rather than allowing you to stop the program and poke around, they simply let it run and keep track of how much time gets spent in every part of the program.

This is particularly useful if you have some code that is running slower than you need it to run, as you can figure out exactly where all the time is going, and concentrate your efforts on fixing just that bottleneck.

Question 7

What is the difference between load and stress testing?

Accepted Answer

A **load test** is usually conducted to understand the behaviour of the system under a specific expected load. This load can be the *expected concurrent number of users* on the application performing a specific number of transactions within the set duration. This test will give out the response times of all the important business critical transactions.

A **stress testing** instead is performed to understand the upper limits of capacity within the system. This kind of test is done to determine the system's robustness in terms of *extreme load* and helps application administrators to determine if the system will perform sufficiently if the current load goes well above the expected maximum.

Question 8

Name some Performance Testing best practices

Accepted Answer

* Test as early as possible in development. 
* Conduct multiple performance tests to ensure consistent findings and determine metrics averages.
* Test the individual software units separately as well as together
* Baseline measurements provide a starting point for determining success or failure
* Performance tests are best conducted in test environments that are as close to the production systems as possible
* Isolate the performance test environment from the environment used for quality assurance testing
* Keep the test environment as consistent as possible
* Calculating averages will deliver actionable metrics. There is value in tracking outliers also. Those extreme measurements could reveal possible failures.

Question 9

What is Endurance Testing?

Accepted Answer

**Endurance testing** — also known as soak testing — is an evaluation of how software performs with a normal workload over an extended amount of time. The goal of endurance testing is to check for system problems such as memory leaks. (A memory leak occurs when a system fails to release discarded memory. The memory leak can impair system performance or cause it to fail.)

Question 10

Explain the purpose of Scalability testing

Accepted Answer

**Scalability testing** is used to determine if software is effectively handling increasing workloads. This can be determined by gradually adding to the user load or data volume while monitoring system performance. Also, the workload may stay at the same level while resources such as CPUs and memory are changed.

Top 29 Software Testing Interview Questions

How to unit test an object with database queries?

What is Load Testing?

Name the difference between Acceptance Test and Functional Test

What is Mocking?

Name some performance testing steps

What is profiling?

What is the difference between load and stress testing?

What is Endurance Testing?

What do I lose by adopting TDD? What are the disadvantages of Test Driven Development?

What is the fundamental value of Unit Tests vs Integration Tests?

Is writing Unit Tests worth it for already exciting functionality?

Name most common problems observed in performance testing

What is a reasonable Code Coverage `%` for unit tests (and why)?

Name some Performance Testing metrics to measure

What is Stress Testing?

Explain the purpose of Scalability testing

Name some Performance Testing best practices

Name some types of performance testing for software

Name some performance testing mistakes

What is Spike Testing?

What is Unit test, Integration Test, Smoke test, Regression Test and what are the differences between them?

What's the difference between Faking, Mocking, and Stubbing?

What are best practices for Unit Testing methods that use cache heavily?

Can Unit Testing be successfully added into an existing production project? If so, how and is it worth it?

Explain some load testing metrics

How to interpret load/stress test metrics?

Why would you conduct Volume Testing?

Is Unit Testing worth the effort?

Could you name some common Performance Testing fallacies?

Top 29 Software Testing Interview Questions

How to unit test an object with database queries?

What is Load Testing?

Name the difference between Acceptance Test and Functional Test

What is Mocking?

Name some performance testing steps

What is profiling?

What is the difference between load and stress testing?

What is Endurance Testing?

What do I lose by adopting TDD? What are the disadvantages of Test Driven Development?

What is the fundamental value of Unit Tests vs Integration Tests?

Is writing Unit Tests worth it for already exciting functionality?

Name most common problems observed in performance testing

What is a reasonable Code Coverage % for unit tests (and why)?

Name some Performance Testing metrics to measure

What is Stress Testing?

Explain the purpose of Scalability testing

Name some Performance Testing best practices

Name some types of performance testing for software

Name some performance testing mistakes

What is Spike Testing?

What is Unit test, Integration Test, Smoke test, Regression Test and what are the differences between them?

What's the difference between Faking, Mocking, and Stubbing?

What are best practices for Unit Testing methods that use cache heavily?

Can Unit Testing be successfully added into an existing production project? If so, how and is it worth it?

Explain some load testing metrics

How to interpret load/stress test metrics?

Why would you conduct Volume Testing?

Is Unit Testing worth the effort?

Could you name some common Performance Testing fallacies?

What is a reasonable Code Coverage `%` for unit tests (and why)?