okay so I just finished the coding round and I'm still kind of shaky so bear with me. posting while it's fresh.
I applied for a new grad / junior role and got scheduled for a technical phone screen. it was 60 minutes, one interviewer, and they use CoderPad or something similar, shared live coding environment.
the problem: it started as what felt like a medium-difficulty array/hash problem. clean input, well-specified, not trying to trick you. the first 20 minutes were fine. then they asked me to extend it: add an efficient lookup, then handle a stream of updates. by the end it had evolved into something that touched caching and time complexity pretty meaningfully.
I wouldn't call it a LeetCode hard but it wasn't a warm-up either. more like a medium that keeps going. the pacing matters a lot because they're watching whether you can think through the evolution, not just solve the first thing.
thing I noticed: they let me think out loud without interrupting much. I filled silences by narrating my reasoning. seemed appreciated.
they also asked one short question at the end: 'walk me through a past project that had a performance constraint.' not behavioral exactly, just like... grounding you in real experience. maybe 5 minutes.
I don't know if I passed yet, waiting on feedback, but the round itself felt fair. the interviewer was patient and gave a small hint when I got stuck. not all companies do that.
if you're prepping for Mistral AI's coding interview specifically: medium difficulty is the right bar, but focus on problems that can be extended or have follow-up constraints. and practice explaining your choices as you code, not after.