I was first approached on LinkedIn and invited to interview for a Data Engineer position in Paris.

The first round (1-hour phone call) involved speaking with a recruiter about my prior experiences, what I’m looking for in my next job, and my interest in the company and role. To prepare, I researched their website to understand their business model and formulate insightful questions.

The second round (1-hour Zoom meeting) was with the manager and the technical leader of the hiring team. It was a two-way interview: they sought to understand my current work, side projects, and interests, while explaining the team's current and future projects and their ideal candidate profile. I, in turn, asked more in-depth questions about their business and technical aspects (stack, vision). To prepare, I reviewed resources from their engineering blog and YouTube talks, which helped me ask engineering-oriented questions during the interview.

Following this, I received a take-home exercise: implementing autocompletion using from-scratch data structures and algorithms, with some follow-up questions on scaling. I focused on submitting a clean solution, including well-documented code and a README file detailing my thought process and design choices.

After submitting, the recruiter contacted me, informing me that we were moving to the final step.

The third round (2-hour Zoom meeting) was with two team members. The interview consisted of:

• 45 minutes reviewing my submission, where I explained specific parts (code, design, choices).
• 45 minutes working on a system design question related to the take-home exercise (how to scale my implementation).
• The remaining time was a discussion where I asked questions about the team, their work, and the role's fit.

I received an offer the following week.

Note: After each interview, I had a brief call with the recruiter for mutual feedback and to set expectations for the next round.

The entire process took a month and was well-designed to allow candidates to prove themselves and filter for those willing to invest the time and energy. The interviewers were very friendly, and the HR members were helpful throughout. Honestly, it was one of my best interview experiences in Paris and definitely worth the time invested.

To help you prepare for your interviews:

• Business: There are many resources (website, client talks, etc.) to help you understand the business and get a glimpse of how it translates to engineering.
• Engineering: You can start by reading the engineering blog posts. This will help expand your knowledge of the solution and how it has evolved over time (by aggregating the different information you will gather).
• Coding: Focus on clean code principles (mainly SOLID) and design patterns, as well as OOP principles.
• System Design: The "System Design Primer" is your friend here. This will be extremely helpful if you haven't done it before.