Things to note before you attend interview for Performance Testing role

Based on my experience as a Interviewer, i would like to share few things which the interviewee must follow/know before attending the interviews for Performance tester role.Couple of things which i felt its really missing in many interview candidates is what i have compiled and provided below. I feel that the below skills are mandatory for any performance tester for 1-2 years of experience.

1. Understand that LoadRunner/Silk Performer knowledge is not everything. Its just a tool which enables us to do better performance testing.

2. Be good in Performance testing terminologies - Types of tests and its objectives,various Performance metrics,monitors,etc. The differences/changes required in scheduling each type of tests should be known.Irrespective of whether you have the responsibility for deciding the test strategy , always know when and why to conduct each of the tests.

3. First, be clear on the objective of conducting performance test for any application. I mean set your own objective that you (along with the team) need to make the system to meet its performance objective. Plan realistic tests accordingly as per the business understanding and try your best to identify various load situations that make the system to fail and work as a team to resolve those bottlenecks. Its not enough to conduct some load tests and say that application doesn't meets it Throughput SLA or response time SLA.How you identify and isolate the bottleneck is more important. What and How you observe and interpret during the test is very important.

4. As a Performance tester, you should know the basic relationship between Hits , Response time , Throughput, etc. This forms the basic for the bottleneck analysis. Increase in response time is not a bottleneck you have identified, its the symptom for some bottleneck. Its a must to identify the hidden bottleneck rather than thinking that's its out of scope of your testing. Its your responsibility to run various isolation tests to gather observations about system performance and provide your suggestions to the DB admins and system admins. Dont forget that its your responsibility to get those people involved to help you out in isolating the issues. I agree that, its a team effort but the sole leader here is the Performance tester who need to coordinate all the other members to get the bottleneck identified. Always think that they are going to help you rather than thinking that you are helping them. That thought makes lot of difference in the ownership you have and the responsibilities you hold.

5. If you are an expert in a specific performance test tool, rank your competency appropriately. Explain what you know and what you don't know. State the reasons for what you don't know and why couldn't use\know that. All the organizations will not look for tool expert who knows everything about a specific tool. Having the tool knowledge is important, but that's not everything. So, be frank enough to tell what you know and what you don't know. How much you are conceptually good is what matters in most of the cases.

6. Atleast in Performance Testing/Engineering field, i definitely feel that a good performance engineer should have referred lot of books/articles/white papers if he/she is really looking for a way to conduct more effective performance tests. Talk about how it made a difference in you/your project.

7. On the whole, the performance tester should include the tool knowledge(1 or 2 tools),knowledge and experience for doing performance requirements analysis to set performance SLAs, Test environment creation details , Bottleneck analysis skills, Basic knowledge about the technology used in the applications and basic knowledge about the OS , Server software & hardware details. (I have just stated the core required skills).

Hope it helps you to relook at your skills and identify the gaps before you attend your next interview.