Screening call followed by interview with the manager and then three interviews with different teams and developers All interviews were virtual as video call or phone calls I didn’t get a feedback at the end of the process

I don't think WhatsApp is actively looking to add team members onboard. Maybe they want to hire engineers with a specialist salary as a tactic to save their costs and they open requisition and keep inviting people on site. I have a lot of reasons to prove this theory: Having a look at the history of the interviews here, you can come to conclusion that they bring the candidates on site and they don't provide any job offer, but instead, they re-post the requisition. I try to think positive. Any recruiter is welcome to do that but there is more to the story: I initially applied and they invited me for first interview but then, I was switching jobs already and not responded to the call. They approached me after 6 months when I had my job so I told myself that I would give this wave of interviews another try. My first interview was a screening. Second interview was a teleconference and very positive and productive. I received some tips about the in person interview. But when I attended the in person interview, it was far from expectation. I had a chat with four different individuals all in one to one format back to back. First chat was including general typical behavioural questions which were easy to respond. "How have you made changes in your job" etc. Second interview was with one of the coders. He was trying to verify and challenge my understanding of OS in general and asking questions on memory management on iOS, threading concept, Virtual Memory Management and SWP Files... Conversation started with "what happens when you press home screen on WhatsApp." I had background knowledge of OS from bachelors but I believe it was not necessary at all for this role. I answered questions in a higher than a specialist level. He neither agreed or disagreed with my responses. My third interview was the worst. One of those typical interviews that someone sits with you to ask pointless questions in order to prove you that you lack essential skills for the job so they can justify their freedom to decline you. So she was basically showing me a schedule for their staff and had blocks missing from schedule and she was asking me to suggest her what activities I should add to the schedule to have a seamless process. I have been trained on scheduling very well in past and in fact I had been a scheduling software trainer. The first step in scheduling is knowing the process of their jobs in detail. I tried to suggest some missing steps based on common sense. On a different paper she was showing me a test case and asking me to improve it. I tried my best to answer but there is no wrong or right unless you really do these jobs. My guide was thinking outside the box and answer these questions based on common sense but the process was such a cliche that I have seen from recruiters who want you to fail. The gray area was intentionally created, solely, to justify the way WhatsApp cherry picks the candidates based on their own personal choices and not necessarily interview process. My fourth interview was with one of their team members. Very nice chat and a lot of common feelings. I think my first out of four and the last were a "Yes". Second chat was a "Null" and third chat was a "Veto No". Good luck with your interviews but have a mind set that if you did not receive an offer, it is probably a norm there. It is not you. I have been an engineer and got a NO for their Specialist Role. No hard feelings! I had a job already and another job offer in hand while I was doing the interviews.