Theodo Fullstack Engineer Interview Questions
& Process

The process has 6 steps in total, each getting harder than the previous one. First, an online technical test (on programming), second HR, third logical puzzle, then TDD test, then an on-site technical test with CTO, finally a test with the CEO (not technical).

The interview process was quite extensive. It started with an initial HR conversation where I was told no preparation was necessary, but then they advised me to be more concise in discussing my background. After passing this, I completed a coding assessment that heavily featured LeetCode-style Data Structures and Algorithms (DSA) questions. I managed to solve two out of three, with the third being a Dynamic Programming (DP) problem. Following that, I participated in a TDD pair-programming exercise, a behavioral interview with the Agile Coach, and a math logic test. In the final round, the CTO reviewed my DSA answers and questioned my inability to solve the DP problem. I explained that my focus was on web development, leaving less time for advanced algorithmic topics like DP. The CTO mentioned the role doesn't involve algorithms but wanted to gauge my knowledge breadth. I then explained the logic behind DP and, with some guidance, solved it using pseudo-code. Despite this, I was rejected due to my non-Computer Science background, with an invitation to reapply after gaining 6 months of FullStack commercial experience. Throughout the process, the Agile Coach provided feedback at each stage, mostly positive, with constructive advice on being more pragmatic, which I feel I improved upon. The rejection felt arbitrary, especially since I was upfront about being a self-taught career switcher with a STEM Master's and was initially assured they welcome diverse backgrounds. The CTO's decision was based on concerns about my background and the required support, overriding the positive feedback from other interviewers. I was disappointed as I had a tour and was assigned a buddy. I shared my feedback on the assessment process, suggesting I was set up for failure, which wasn't well-received. Submitting my DSA assessment four weeks prior to the CTO interview made the rejection based on it and my credentials unexpected, as I had passed that stage. It appears there's a misalignment between the Agile coaches' and CTO's hiring metrics for junior roles. I'm sharing this in case the process has changed.

The interview process was really well put together and fun. It was all online and had a few different stages. First, there was a 30-minute behavioral chat with HR about why I'd want to join a fast-paced company. Then, a 65-minute Codility test online with three coding problems in JS or Python, starting easy and getting harder. After that, a 3-hour virtual on-site with three parts: a 60-minute logic interview where I had to solve 3 riddles, a 60-minute pair-programming session with an engineer on a simple task using TDD, and a 45-minute culture fit interview that felt more like a conversation. Finally, a 60-minute culture fit chat with the CTO, which was more about the big picture. I got a good vibe from the company overall, but ended up taking another offer that felt like a better match.