Preparation for SDET Interview
By: Baldev Bhaliya
Tags: Interview Preparation, QA, Sdet, Automation Testing, Automation

As we know SDET interviews are not less than developers interview. As in IT industry SDET are getting more popularity, as they can code & do functional testing. Here I am going through how anyone can prepare for SDET interview.

1 Get Company/Product knowledge: First & foremost, you must know about what product they are dealing in, what domain they are working on.

- Go through their applications and try to understand what kind of automation they need, what kind of functionality issues can come & what could be different challenges.

- If its new domain than research on how to do automation in that domain e.g like audio, video or real time applications

2 SDET Capability: So before starting, what is expected from SDET or we can say what is the role of SDET?

SDET’s are tester with coding skill. We always see in developers profile full-stack developer, similarly SDET’s are full stack QA. Expectations from SDET, they can do functional testing, automate same workflow’s or API’s & if require they will perform Load testing.

As you understand it is very critical role in terms of skills & technology. Now coming to point, SDET interviews are mostly based on functional testing, logical thinking, automation framework & performance if required.

A. Functional Testing: Interviewee will try to rate you based on how do you think & what different test scenario you can think of. This includes positive, negative or any corner cases you can list down.

This will be scenario based, where interviewee will give scenario which might have API’s or dealing in concurrent environment like multithreading or any UI based applications. Also, once you list down all scenario, interviewee might ask you, how you replicate this scenario in actual environment? for e.g. Replicate scenario where product in cart will expire after 21 days. For this you will prepare data in DB for particular user & try to replicate that scenario with that user.

B. Data structure & Algorithm: This is general approach to find out how person think to solve any problem. For SDET, this won’t be typical dev type but similar to that.

H ere interviewee will ask questions like finding duplicates from array, unique chars in string or reverse a string. Point to be noted interviewee expect multiple approach from basic level to expert level. Solve it using basic flow & interviewee will more add complexity. Interviewee will check how much you fight to solve it, how you think to solve this problem. You might not able to solve it, but what different approach you have tried is more important.

C. Automation Framework: Typical question what framework you have used. This is your time to show off ;) Prepare yourself for this question before any interview & get ready for cross questions. So, any Automation framework should support at least following:

a. Can we run on different Environment without any change in Code?

b. How reporting will be useful?

c. Can we execute testcases parallel?

d. How testcases are independent of each other?

e. Can we support different browsers/mobiles/Android/iOS?

f. How it will be integrated with CI/CD?

Following different questions you can prepare for interview. Use Google or any other medium to get answer of it.

- How to reduce execution time? By parallel execution.

- How you will do parallel execution? TestNG approach

- Most common issues faced during UI automation? staleElementException, NoSuchElementFoundException, ElementNotClickable

- How to solve above issues? Just google it out & try yourself

- How do u automate on different size/version devices? By different capabilities in config files

- How do u debug any failure in UI automation? By taking screenshots or recording request & response at the same time & sharing it in reports.

- How Appium works internally? Read about Appium engine, they expose API’s accessible using drivers & connect to any device via command tools.

Different types of framework:

a. Linear Automation Framework: Used for small applications

b. Modular Driven Framework: Create test scripts module wise by breaking down the whole application into smaller modules

c. Behaviour Driven framework: Natural language to create test specifications on this behaviour driven testing

d. Data-Driven Framework: Test Data is read from the external files like Excel and they are loaded into the variables inside the Test Script

e. Keyword-Driven Framework: Automation test scripts performed are based on the keywords specified in the excel sheet of the project.

f. Hybrid Testing Framework: Combine the benefits of Keyword Driven and Data-Driven frameworks

Page Object Model is not a framework, you can talk about Page Object as design patterns if talking about UI automation.

3 Added skillset: As I mentioned SDET are full stack QA. It is plus point to have good expertise in Performance testing, security testing, leading a team, specific achievement like blogger or Presented in any summit. Also, when we add this in our resumes do expect question around it. Do read about JMeter or any other performance tools. Also, go through different proxy tools like charles or BurpSuite for app testing.

Please NOTE, do not mention in resume if you haven’t worked on Performance or security testing.

4 Never give up mentality: Every problem will have different solutions. If you solve a problem in a minute or 2 then interviewee might think he has read it somewhere else. So again he might ask you different problems.

Try try you will succeed this is the attitude interviewee looking out for. Never give up on anything easily, try to think from every aspects. Point here is interviewee try to look how many ways you can solve problem, even if you are not able to solve it, what different approaches you have tried.

5 Be clear & confident: After every answer ask interviewee did u satisfied with answer or do you want something else. Sometime it may happens that interviewee’s expectations is something else & what you answered is something else.

No one knows everything, if you don’t know something say u don’t know but don’t bluff anything. You can talk about side things if needed but bluffing will put you into trouble.

6 Mock interviews: This is important as candidate get nervous sometime in interview.

It will be good practice to get interviewed by friend/colleague before actual interview.

7 Coding Skills: SDET should have very good expertise in any of programming language used in automation. There will be rounds where interviewee ask about programming language questions.

8 Online Test: Nowadays, every company is getting too many profiles. They can not review each & every profile. What they do is ask candidate to give online test & they put benchmark for every test. Once you clear it they go through your resume & if they find good they will call you for interview. There are multiple platforms which provides this facility like HackerRank.

Signup today & start solving at least 1 problem a day from such platforms. It will increase your confidence in online test.

9 Levelling: SDET’s also have different level. If you are junior then expectations will be little bit less but as you go higher expectations will be higher.

They might compare candidate with their best employee while levelling.

Take some time before scheduling any interview as preparation will take some time.

Conclusion: SDET are full-stack QA, who knows everything about product testing. SDET knows functional, automation, performance & even security testing. Cracking interview is not simple but with proper guidance & preparation anyone can crack it.

Good Luck & ALL THE BEST ! ! !