HackerRank's entire interview process was quick, well-planned, and to the point. I applied for the Senior Frontend role. It went through a total of 8 rounds.

Initial Screening: I received a call from HRM regarding an opening at the company. After an initial chat, in a subsequent email, I was asked to pick a slot for an initial screening with one of the engineers.

The focus was mostly on Data Structures, Algorithms, and how well-versed one is with JavaScript & CSS. The interviewer was nice, polite, and calm. He explained the development work that was going on.

Onsite Round: I am not from Bengaluru, so I had to fly in.

There were a total of 5 rounds. The onsite interview was incredibly planned. A whole day's timetable was displayed on a big screen in a separate meeting room. Everyone was aware of what they were doing. All instructions were given, such as the CodePair link and Wi-Fi password, to avoid chaos. Also, the place was very cool, and I was told to wear anything that I was comfortable with.

1. CodePair Round with Engineering Manager: It started with a quick introduction. Basically, two questions needed to be solved on the HackerRank CodePair platform. The first one was really easy and felt like an icebreaker. The other question was of medium difficulty. The interviewer was helpful and humble. All test cases were supposed to be passed within the stipulated time period.

2. Advanced JS Round: This was conducted by a senior engineer from the frontend team. It covered JavaScript in depth. Questions were related to PWA, Service Workers, the use of lifecycle methods to design HOCs using IntersectionObserver, Maps, WeakMaps & their uses, performance-related questions, and the underlying implementation of two underscore methods. Questions about CSS & Animation were also included. The interviewer was very friendly and didn't make me feel uncomfortable when I couldn't answer.

3. Discussion with VP: This was more about work patterns, my previous organization's team structure, and processes. Questions focused on what excites me, especially in programming.

4. Discussion with FE Architect: The interviewer was looking for an understanding of the fundamentals of programming in this round. The focus was on design patterns, the underlying implementation of React APIs, performance, and UI use case implementations. The person had in-depth knowledge.

5. Culture Fit Round: Basically, they were testing the person by putting them in a situation. Emphasis was placed on the four core values, which are generally found in every correspondence email.

One day after the onsite interview, I received a take-home assignment that was supposed to be finished by the weekend. After the submission of the assignment, there was one more CodePair round with the CTO. Again, there were two complex problems to be solved on their CodePair platform in one hour. I solved three instead of two. The first problem was regarding string operations, which was quite easy. Then, another question was related to parsing a spreadsheet cell ID. The third problem was based on regex.

In short, there were a total of 8 rounds, but it did not take too long. The onsite interview experience was memorable.

For the onsite interview, if you were coming from a different city, you had to book air tickets yourself, which are obviously reimbursable regardless of your interview result. They also provided accommodation for one night in a good hotel nearby.

At the end, I received a jaw-dropping offer.

Questions were related to:

• PWA
• SW (Service Workers)
• Use of lifecycle methods to design Higher-Order Components (HOC) using IntersectionObserver
• Maps and WeakMaps and their uses
• Performance-related questions
• Underlying implementation of 2 underscore methods
• Questions about CSS and Animation