How to Hire a Software Tester

For this month’s post, I’m doing something a little different! Usually my posts are aimed at software testers who want to improve their skills and improve their thinking about what to test. But this month, I want address the people who hire the software testers!

Making the right hiring decisions is crucial. Being saddled with an ineffective tester is often worse than having no tester, for the following reasons:
• They may fail to automate any tests, meaning that all testing will be manual and will be a huge bottleneck to releasing software
• They may automate their tests poorly, resulting in flaky tests that no one trusts and that require tons of maintenance
• They may fail to grasp technical concepts, meaning that other team members will have to waste time explaining those concepts to them again and again
• They may be inept at creating test strategies, resulting in the wrong things tested and the right things not tested at all

So, to avoid hiring an ineffective tester, I recommend that you look for the following ten skills:

Able to find bugs
If the tester can’t find bugs, there’s really no reason to employ them. Any developer on the team can do “happy-path” testing and put together automated tests for their code. What sets testers apart from the others is their ability to think of things to test that the developers might miss: negative tests, strange edge cases, interactions between features, and so on. To determine whether a candidate can find bugs, give them a buggy application and ask them to find and report on the bugs. You will be surprised how many “experienced” testers can’t do it! And these are the people you will not want to hire.

Makes good decisions about what to test
A tester that can’t prioritize what should be tested will not be an effective worker on your team. Testers should be able to determine what should go in a smoke test, what areas of an application should have regular regression tests, when it’s the right time to search for an elusive bug, and when it’s time to save the search for later. To determine whether your candidate can think strategically, present them with an example application or system and ask them to design a test plan for it. One easy example is a soda vending machine. While your candidate may not know the mechanisms involved in delivering the soda, they should be able to identify the different tasks of the machine and come up with systematic ways to to test them.

Understands API testing
If your application uses APIs at all- and most modern applications do- you’ll want to make sure that your candidate understands how to test them. I continue to be surprised at how many testers still don’t understand how to test APIs (a problem that could be easily solved by taking my Postman course or reading my new book) when they are so prevalent today. A poorly developed and tested API can result in serious security holes and a poor user experience. To make sure that your candidate knows how to execute API tests, give them a sample API to test. See if they are capable of creating both positive and negative test scenarios.

Communicates clearly
A tester who can find bugs, but can’t explain to anyone how to reproduce them is not going to be particularly helpful. Software testers need to be excellent communicators. To check if your candidate is a clear communicator, ask them to explain a complicated bug they’ve found in their current position. This actually accomplishes two things: it verifies that they actually find bugs in their current position, and it also gives you a sense of how the candidate explains a complicated situation. If you can’t follow along with their explanation, this might not be the right tester for you.

Writes good test automation
According to Robert C. Martin, the author of the widely-respected book Clean Code, test code is just as important as production code. This is because test code is used to validate that changes in production haven’t broken anything. If the test code is unreliable, then all changes to production code have to be manually tested in addition to being tested with automation, which slows the entire development process down. Because of this, you want a software tester who writes clean automated tests: common tasks should be separated out into methods or classes, and the code should be well-organized. To check whether the candidate can write good test automation, ask them to write some automated tests for a simple application. Then ask them to run the tests for you and explain why they wrote the tests they did, and why they organized the code the way they did.

Understands databases
Whether you use relational databases like SQL Server or non-relational databases like Mongo DB, you’ll want your candidate to be able to interact with the databases to get the information they need for testing. If you use relational databases, ask them to write a simple query or a join. For non-relational databases, you can ask them how they would get a specific record from the database.

Understands the challenges of mobile testing
If you have a mobile application, or if your application has a mobile version, you’ll want to make sure that the candidate understands the the challenges of mobile testing. Ask them what those challenges are; you should hear things like differences in screen size, operating system, version, carrier, and so on. If your application is primarily mobile, you’ll also want to make sure that your candidate has experience with mobile automated testing.

Understands the basics of security and performance testing
Even if you have security and performance test teams at your organization, you’ll still want to make sure that your candidate understands some basic security concepts like privilege escalation and IDOR, and some simple performance concepts like measuring page load times and API response times. For smaller companies that don’t have security and performance test teams, understanding these basics is even more important.

Understands the importance of visual and accessibility testing
The candidate should be able to identify some reasons why visual automated testing might be needed. For example, ordinary UI test automation does not validate that an image is appearing correctly in a browser, but a visual testing tool can do that. They should also understand that accessibility is an important aspect of web applications today; they should be able to give you some examples of accessibility needs, such as the ability to zoom in on text, use a screen reader, and view videos with captions.

Can be an advocate for quality on your team
Finally, you will want a candidate who is able to speak up when the situation calls for it. A tester who can find bugs, but who can’t advocate for those bugs to be fixed, will not be much help to your team. In today’s Agile software teams, the tester acts as more of a quality coach, helping all the team members to think like testers, do exploratory testing, and contribute to the automation code.

A poor software tester can be a drag on the entire team, but a good software tester can spur the team on to new heights of quality and productivity! With these skills in mind, you will be able to hire testers you will be grateful to work with.