Software Engineer (L4) Interview Experience

I answered this at a pretty high level. The whole call felt more like they were trying to understand me as a person and what motivates me than score me on anything, so I kept it top level and fit-focused.

I gave a very cursory overview rather than a chronological deep dive. They were not probing hard on impact, ownership, or technical depth yet. It was more just making sure my background matched the team and level.

Are you authorized to work here, are you open to relocation, and are we aligned on level and role details?

I just confirmed the basics like work authorization, relocation openness, and the level I was interviewing for. It really was a checklist call more than anything else.

Complete the Google Hiring Assessment questionnaire.

It was a hundred-plus question async questionnaire. I treated it as a consistency test more than anything else. My prep was basically to keep my answers consistent across similar or inverted questions, and not sit in the middle on every scale.

I started with the fundamentals I knew, and when I mentioned I remembered sorting was n log n but could not fully recall why, he pushed there on purpose. We rebuilt it from first principles together and talked through big O and common algorithms. It felt like he was trying to get to the edge of what I actually understood in real time, so I stayed collaborative and reasoned out loud instead of trying to bluff.

I treated it as an algorithms problem distributed across workers. I talked through splitting the data, sorting partitions independently, and then merging across workers, and I also layered in a little real-world production thinking around scaling because I think that signals seniority. The prompt itself was very open-ended, so the important part was structuring the approach clearly.

I focused more on requirements than code. I clarified the exact input format, what invalid input should do, and which edge cases I would guard against before writing much syntax. He seemed much more interested in whether I scoped the function cleanly and set sensible checks than in the implementation itself.

The question needed a decent amount of clarification, so I whiteboarded edge cases with the interviewer first. Once we constrained it to lowercase letters, the core insight was that it came down to character frequencies, specifically whether the frequency multiset matched across the two strings regardless of which letters the counts were attached to. I also volunteered time and space complexity as I discussed approaches, so I was not really pushed on that at the end.

It was basically the cheapest K stops style graph problem but translated into train-schedule language with more variables, so the first step was clarifying the requirements. We aligned that the real goal was getting from A to B arriving as early as possible, not just minimizing stops. I modeled it as a Dijkstra-style shortest path problem, gave time and space complexity up front, and then spent the rest of the round coding because the setup itself was already pretty dense.