The Tech Interview Behind the Scenes: Angel Petrov
The Tech Interview Behind the Scenes is an HRLabs series.
Let’s take a look behind the scenes of the technical interview process from the interviewers' perspective.
Our goal is to provide candidates with valuable tips and recommendations directly from professionals who conduct interviews for various technical roles.
“Whatever you’re learning, approach it with understanding – simply memorising a term or definition is far from enough.” advises Angel Petrov, Technical Product Manager @Broadcom.
Tell us more about your career path.
It all began in the fall of the distant 2008… It sounds like a fairytale, but it’s true that I didn’t even realize how these 16 years flew by, filled with many challenging projects, successes, and, of course, failures.
For 16 years now, I’ve been navigating the IT field, with the majority of my experience tied to Quality Assurance. For more than 13 years, I’ve been learning, and at some point, teaching the intricacies of being a good QA. Out of those 13 years, I spent around 10 years building and managing QA teams, actively participating in interviews and recruitment, training, and supporting the career growth of many people I had the pleasure to meet and work with.
For over 5 years, I taught at Swift Academy, where I aimed to pass on my knowledge and experience to people looking to retrain and enter the tech world.
I’ve participated in over 500 interviews, both for positions in Bulgaria and for roles in the international offices of the companies I’ve worked for. The truth is, with every interview, you get better at “reading” the person across from you.
I have experience in testing, primarily as part of product companies, where deep knowledge of the product being developed is essential.
For almost the past 3 years, I’ve been working as a Product Manager and have come to realize how valuable my experience as a QA Manager and QA Lead has been.
What I’ve learned over all these years is that a good leader is always there to help and, together with their team, is ready to go through all challenges to achieve the ultimate goal. It’s crucial that all the knowledge and skills we gain are shared and used to help newcomers learn and, why not, even surpass us.
As a candidate, have you had any strange interviews? What about interviews that impressed you?
Given the large number of interviews I’ve conducted, I’ve come across all sorts of peculiarities. I’ve been part of unusual interviews, as well as ones where candidates performed brilliantly but later disappointed in a work environment.
Overall, to conduct an interview effectively and efficiently, you need not only solid preparation but also a bit of luck and a sixth sense to guide you. The whole process is truly a science!
I’ve also been on the other side of the table as a candidate, and I know how strange it can feel. The entire process is very important, and it’s not enough to simply evaluate a candidate’s technical and personal skills; the interviewer must also be able to clearly explain the essence of the position being applied for.
Let me use a cliché – "overqualified."
It’s crucial not only for the interviewer to recognize when a candidate is technically suitable for a position but also for the candidate to understand what will be expected of them and the tasks they’ll be performing to avoid disappointment later on.
What skills and qualities do you look for in a candidate? How can a candidate stand out during the interview?
First and foremost, I look for candidates who have the technical skills required for the level they’re applying for.
Another quality that’s extremely important to me is how much of a team player the person is. I value this quality immensely because, for me, the saying “a united team can move mountains” holds true. In tough situations and complex challenges, teamwork has always been what got me through.
I also always look for curiosity and openness to new knowledge in candidates. None of us were born knowing everything, which is why we need to keep learning and developing every day. But to do so, we need a dose of curiosity – the drive to seek answers and solutions even to the most complicated problems.
What questions do you typically ask in technical interviews? Do you have specific tasks or problems that you often use to assess candidates?
I’ve never gone into an interview with a pre-planned script or a fixed list of tasks and questions – at least not after my first 2-3 interviews. Instead, I have a large pool of tasks to choose from depending on the candidate and how the interview progresses.
It’s also crucial to constantly update and create new tasks. Experience has taught me that right after interviews, people often share the questions and tasks they were given, quoting them in detail.
My favorite approach, which I always apply, is to verify every answer to a theoretical question with a task or case study. This helps me assess whether the theoretical knowledge is backed by understanding or simply memorized.
I’ve also assigned projects with deadlines, which include writing tests based on business requirements, testing tasks, and bug-finding challenges. I evaluate not only how the candidate completes the task but also their reasoning and presentation. For instance, did they write the tests in Excel or use a Test Case Management tool with a free trial registration?
As I mentioned, providing the correct answer isn't always sufficient – demonstrating the thought process behind it is equally important.
How important are good communication skills for a candidate? How do they impact the overall interview?
As someone working in Quality Assurance, this is one of the most important qualities every candidate should possess. QA specialists must act as mediators between what the client wants and the actual implementation that developers have delivered as functionality.
Sometimes, these discussions can be quite complex, and the ability to communicate effectively and present solid arguments is essential. If I were to answer this question directly and clearly, the answer is yes – it is crucial for candidates to have strong communication skills.
How important is cultural fit when making a hiring decision? How do you assess whether a candidate will fit well into the team?
My personal experience shows that a company’s culture is incredibly important! It’s the “spice” that makes a company unique and different.
This applies equally to the individual teams within the same company, where what I call micro-cultures are formed. When a new person is hired, they inevitably go through several stages of integration, both into the micro-culture and the specific company culture.
Introducing someone with completely opposite personality traits into this environment often makes the integration process quite challenging and, in many cases, impossible.
In this context, I’ve had situations during interviews where a candidate performed flawlessly in their technical tasks and questions but was still not hired.
What are the most common mistakes candidates make during an interview? What advice would you give candidates on how to prepare for an interview?
The most common mistakes I’ve encountered often stem from excessive theoretical preparation.
Sounds strange, doesn’t it?
The truth is that people focus on learning concepts like Priority and Severity and can “recite” them textbook-style, but when challenged to apply them in practice, it turns out they haven’t grasped the essence. Whatever you’re learning, approach it with understanding – simply memorizing a term or definition is far from enough.
For more experienced candidates I’ve interviewed, I often come across the “comparative analysis trap.” Every answer is filtered through the lens of what they’re currently doing at their current employer. The truth is, no matter how well a specific approach works in a given environment, product, or task, it doesn’t necessarily mean it will yield positive results in a different context or setting.
My advice is to step out of your comfort zone and think outside the box, where the “box” might represent your current period, employer, tasks, experience, and so on.
What advice would you give to candidates who want to improve their technical skills? Are there any resources you would recommend?
Reading, reading, and more reading! To everyone who’s attended my courses, I’ve always emphasized that every article they read will provide them with new knowledge.
For those new to testing, I recommend crowdsourced testing platforms. There are several of these that help beginners gain experience while also earning a little money. One particularly useful platform for beginners is W3Schools Online Web Tutorials, where they can learn the basics of SQL, HTML, CSS, and more.
We are an internet-driven society with an abundance of information around us – all we need is self-discipline, determination, and perseverance.
As an instructor who has trained over 400 students, I’ve always maintained that after completing a course, it’s better not to immediately dive into the next one. Instead, build on the knowledge gained during the course with additional materials and reading.
Many people rush from course to course, thinking that the more certifications they have on their CV, the better their chances of being hired. In my opinion, enrolling in course after course, especially for those without prior experience in the field, can be counterproductive. The sheer amount of new information can become overwhelming and create confusion instead of clarity.
Share more about the best (or worst) interviews you've conducted.
One of the worst interviews I’ve ever been part of was when I was in the role of interviewer.
There were several of us as technical leads conducting interviews together since we had open positions in our teams. During one of these interviews, a colleague was presenting technical tasks to the candidate in an extremely unclear way, putting us in an awkward position.
Imagine applying for a job and being interviewed by the company’s leaders, who are presenting incorrect or poorly worded technical tasks. It was one of the most unpleasant interviews I’ve experienced, but also one of the most instructive.
To avoid embarrassing ourselves in front of the candidate, we had to clarify the technical task at one point, while trying not to undermine our colleague. After the interview, we gave them constructive feedback, and thankfully, it didn’t happen again. We hope the candidate didn’t notice the awkwardness of the situation we inadvertently put them in.
How do you evaluate a candidate during an interview—based solely on their theoretical knowledge, or is their approach to solving a problem/task more important to you? What other factors do you consider when making a decision?
The evaluation process itself is quite complex and involves a degree of subjectivity.
One of the important factors is how technically prepared the candidate is, but that alone is not enough. Sometimes, technically skilled candidates, when faced with a more complex problem to solve, struggle and can’t always find a way out of the situation.
A major factor is how a person handles an atypical task – one that occurs rarely and doesn't have a pre-determined set of correct solutions. In such a situation, character, intuition, and analytical thinking are crucial, as they help to provide potential solutions to the problem, even if it’s unclear whether they are the right ones.
Another key factor is whether the candidate will fit into the team culture, as well as the company culture.
Share a funny story from your experience as an interviewer :)
One of the funniest situations I can share is related to an interview with a candidate for the position of QA Engineer.
As with every interview, we start with a few routine questions to break the ice and reduce the tension for the candidates.
I asked the candidate to share what his previous experience was and what projects he was working on at his current employer. He told me that he had been a QA for 5 years, but was hesitant to mention what he worked on and what experience he had, quoting: "so you won’t laugh at me." My automatic response was that whatever happens during the interview stays between us. This calmed the candidate, and he shared with me that he tested adult content websites.
Immediately after that, he looked at me and said:
"You understand, I test them manually, and it's quite stressful!"
After that answer, it was truly a challenge for me to hold back from laughing and continue the interview, but professionalism was my duty.
For the curious, I didn’t hire him as he lacked the necessary experience.