When a recruiter contacts you, they first prepare a first interview that can disqualify you from the process. You can schedule this interview whenever you want; I requested a month for preparation.

The first interview consists of two LeetCode-style problems of Easy difficulty (covering node trees, double pointers, arrays, strings) that you solve collaboratively with the interviewer. You have 40 minutes to solve them, and as you finish one, you move on to the next. The interviewer usually offers help if you get stuck.

If the feedback is positive, you will meet with the recruiter again, who will explain the next steps. This phase consists of four 1-hour interviews. All interviews have a similar structure, including the first phase's interview. There's a 10-minute introduction between you and your interviewer, followed by approximately 40 minutes of technical testing and 10 minutes for questions.

The first interview of the second phase is identical to the phase 1 interview. It involves one or two LeetCode problems, where I was advised to review medium-high difficulty ones, although in my case, it was an easy-medium level. In my situation, it was a single exercise where halfway through, the interviewer introduced a change that made it slightly more complex.

The second interview consists of an HTML and CSS test with React. It's a small project with pre-built utilities (for formatting and similar tasks); the interviewer can guide you on using these utilities. You need to demonstrate basic HTML and CSS knowledge (paying attention to accessibility and semantics), along with some React knowledge, hooks, etc.

The third interview is a system design interview, where your knowledge of everything that makes up a Frontend view is paramount. It includes some UX, networking knowledge, and product design.

For the last interview, you are asked to prepare a project you've previously worked on and explain technical details using the STAR framework for approximately 15 minutes. Afterward, the interviewer will ask you specific questions about that project for 10 to 15 minutes. The final 10 minutes of the technical test are dedicated to questions based on Datadog's values (e.g., "Tell me about a time you received tough feedback?").

The recruiter will provide feedback on the test. If it's positive, they will put you in touch with the managers of teams seeking profiles for your position. You'll have relaxed, pressure-free conversations with them, as you've already demonstrated you're a good fit for Datadog, and they want to ensure you find a comfortable place within the company.

In my case, there were two such sessions before an offer was made, which came after a visit to the Madrid office.

LeetCode easy: arrays, double pointers, strings, node trees.