Just finished the Pinterest coding interview process (SWE, mid-senior level, SF) and wanted to post actual signal since most threads are from 2023 or earlier.
The OA was on CodeSignal. Two problems, 70 minutes. First one was a graph traversal problem, genuinely medium difficulty. Nothing tricky about the constraints. Second was a variation on interval merging. If you've done any LeetCode prep at medium tier, you're not going to be blindsided.
They do NOT do a HackerRank-style timed auto-graded OA at the phone screen stage. The recruiter phone screen is separate and comes first. The coding OA comes after that, before the full loop.
For the technical phone screen, it was one 45-minute session with an engineer. They gave me a graph/BFS problem. Moderately hard medium. They cared a lot about me talking through the approach before writing anything. I started coding too fast and got a gentle redirect.
Things I noticed: They don't do system design at the phone screen level They do care about code quality, not just correctness. I had a minor bug, found it myself, explained the fix. Seemed fine. Expect Python or Java to be most natural; they can do Go/C++ but the interview templates seem Python-optimized
Overall the coding difficulty is a notch below Google's bar but a notch above a standard Series B startup. Solid medium consistently. I prepped with about 30 targeted mediums and felt ready. LC Hard felt unnecessary for this level.