The interview process was long and challenging. It was important to think out loud, propose multiple solutions, justify a single choice, and be able to give the time and space complexity for the solutions.

I'd suggest listening closely to the suggestions of your interviewers, considering the efficiency of your solutions (think memoization, virtualization), and being explicit about the challenges, base cases, edge cases, and bottlenecks of the problem.

I'd also suggest explicitly giving test cases for the coding challenges (e.g., console.log(myFunction(1, 2), 4)).

There were several points where I could have exited the interview process if I had performed poorly.

At the end of each interview, I could discuss the position with the interviewers and ask questions. My recruiter and I touched base frequently to ensure I understood everything and to debrief each interview.

Specifically, my interview steps were:

1. HIGH LEVEL INTERVIEW WITH RECRUITER (30 min, Zoom) [EXIT POINT 1. Recruiter checked in with hiring managers.]
2. LIVE CODING TECHNICAL SCREENING (1 hour, Zoom and Coderpad) [EXIT POINT 2.]
3. FRONTEND SYSTEM DESIGN (1 hour, Zoom and Excalidraw)
4. REACT LIVE CODING (1 hour, Zoom and Codepad) [EXIT POINT 3.]
5. LIVE CODING (AGAIN) (1 hour, Zoom and Codepad)
6. HIRING MANAGER INTERVIEW (1 hour, Zoom) [EXIT POINT 4.]

At this point, I was told that they were interested in hiring me, and I conducted placement interviews with the managers of two prospective teams. We agreed on the team that I was more suited for, but I was informed that if I had not been a good fit for either team, they would have explored other options.

They sent a formal offer which was exactly as I had discussed with the recruiter, and I accepted.

As I mentioned before, it was a very long process. I ended up taking 3 months to complete everything, mostly due to my busy schedule and wanting to leave time for preparation.

All in all, my recruiters were amazingly helpful, gave great tips, and were very clear about the offer from the beginning. All of the interviewers were patient, clear, and open to the questions I posed.

1. HIGH LEVEL INTERVIEW WITH RECRUITER (30 min, Zoom) I gave an overview of my background, experiences, and a previous project I had worked on in some technical detail, and why the position was interesting to me.

2. LIVE CODING TECHNICAL SCREENING (1 hour, Zoom and Coderpad) Two relatively easy (leetcode easy/medium) questions were to be solved with JS or TS. One was a typical string manipulation question which required no particular algorithmic knowledge, and the other was a problem where knowing graphs was particularly helpful. I was allowed to do MDN searches or ask for help where necessary.

3. FRONTEND SYSTEM DESIGN (1 hour, Zoom and Excalidraw) The task was to architect a solution for a frontend app (no need to discuss typical system design topics like load balancers, etc.). The idea was to determine a basic design and user flow/UX for the application described. The major considerations were application performance, user interactions, frontend-backend interactions (what endpoints and what kind of data and why), data structures/state, and any libraries or techniques I would use. It was important to identify performance bottlenecks and their solutions (DOM rendering, lazy loading, caching, etc.).

4. REACT LIVE CODING (1 hour, Zoom and Codepad) A basic React problem. I needed to parse some data and display it in an existing app. It was important to be intimately familiar with React, to know my way around React hooks, and think about the efficiency and readability of my code. I'd advise being particularly diligent concerning performance optimizations. Again, I was allowed to consult MDN, React docs, etc. TS or JS is fine. At one point, my computer started lagging, and I had to quit the call and restart my computer. The interviewer was completely understanding and gave me some extra time.

5. LIVE CODING (AGAIN) (1 hour, Zoom and Codepad) A harder problem (leetcode medium/hard) to be solved with JS or TS. The problem involved string manipulation and pattern matching and could be solved in a variety of ways, including 2 pointers, dynamic programming, depth-first search, recursion, etc. As I went along, the interviewer added more criteria, so it was important to be able to be flexible.

6. HIRING MANAGER INTERVIEW (1 hour, Zoom) Two interviews in one: one part was a traditional interview describing my experience and why I wanted to work for Datadog and what I wanted to do at Datadog. The other part was the presentation of a project that I had worked on in the past. They wanted to see that I had a sense of ownership of the project, that I had experience working across teams, that I was capable of leading a team and being the point person for implementing a technically challenging solution. They wanted to know how I navigated the difficulties of heading a project. I prepared a diagram ahead of time using Excalidraw to explain the technical aspects and architecture to make things go a bit smoother.