Just finished the BlackRock OA and phone screen for a software engineering role (NYC, 2026). Documenting everything because I was searching for this info for days and found almost nothing recent.
Online Assessment (HackerRank)
90 minutes, 2 coding problems. Not particularly hard by Leetcode standards but you need to actually code them correctly, not just wave at the solution.
Problem 1: array manipulation. Think sliding window or prefix sums. Medium difficulty. Test cases were not tricky, just make sure your edge cases are clean.
Problem 2: graph traversal with a financial flavor. Something like: given a directed graph of asset dependencies, find all assets that would be affected if a given asset fails. BFS/DFS, nothing exotic. The framing was domain-flavored but the algorithm was standard.
Language choice was open. I used Python. Seemed fine.
Phone Screen (with an engineer, ~45 min)
One coding problem, shared via CoderPad. Medium Leetcode, string manipulation. Interviewer was chill and let me talk through my approach before coding. No trick questions, no obscure data structure knowledge required.
They asked a few follow-up questions after I got it working: time complexity, how I'd handle scaling, one minor edge case I'd missed. Pretty standard.
Note on difficulty: BlackRock is not trying to replicate the FAANG gauntlet. The bar felt closer to "can you code clearly and explain your thinking" rather than "can you solve Leetcode Hard under pressure." That said, don't underprepare. Sloppy code or wrong complexity answers will still knock you out.
Prep I'd actually recommend: 20-30 Leetcode mediums with clean code, practice talking out loud (seriously, the CoderPad interviewer is listening the whole time), and read a bit about financial data structures if you can. Knowing what a time series is versus a snapshot helped me in the debrief.
Waiting on results now. Fingers crossed.