Did PIMCO's coding interview earlier this year as part of a new-grad-adjacent process (I'm a career changer, so I was targeting something between entry and mid-level). Wanted to document the OA format because I couldn't find much specific info when I was preparing.
Format: The initial online assessment was on HackerRank. Two problems, 90 minutes total, no proctoring or video, just the usual code editor.
Problem 1 was what I'd call easy-medium. String parsing with some edge cases. I finished in about 25 minutes and spent another 10 cleaning up and testing.
Problem 2 was solidly medium. Array manipulation, involved tracking state across a traversal. I got to a working brute force pretty fast but the test cases had time-sensitive inputs, so I had to optimize. Ended up with an O(n log n) solution after rethinking the data structure. Passed all visible test cases, not sure about hidden ones.
Nothing financial domain specific. No fixed income math, no algorithm that only makes sense in the context of portfolio management. Just DSA.
After the OA: recruiter reached out within 48 hours to schedule the technical phone screen. So they move relatively quickly.
Prep that helped: I did maybe three weeks of LeetCode medium problems before this, focusing on arrays, strings, hash maps, and trees. I didn't touch DP at all and it didn't come up. For the role I was targeting (more backend infrastructure than quant/analytics) they seemed to care more about clean code and optimization than exotic algorithm knowledge.
One small thing: they did have a brief non-technical component at the start of the HackerRank assessment. A few multiple choice questions about how you'd handle a team situation. Not hard but worth knowing it's there so you don't panic and think you got the wrong link.