Went through Dropbox recruiting this spring (2026) for a mid-level SWE role. Here's the full picture on the coding rounds.
First touch is a HackerRank OA, 90 minutes, two problems. When I did it the first problem was a medium-level array manipulation (sliding window variant), second was a harder tree/graph problem that probably maps to LC medium-hard. Not hard to distinguish which is the "filter" problem vs which is the stretch.
After OA there's a phone screen coding round, 45-60 min with a live interviewer. Mine was on CoderPad. Problem was graph-traversal adjacent, specifically something about finding connected components given a certain constraint. I'd describe it as solidly LC medium. The interviewer talked through it with me, nudged when I went down a dead end, and asked about time and space complexity at each step.
If you make it to onsite, there are two coding rounds. One felt more "pure" algorithms (tree-based), the other was more practical: given a data structure representing file paths, implement some operations on it. That second one felt closer to real engineering, which I liked. Still LeetCode-able, but not in a formulaic way.
Difficulty overall: if you can solve LC mediums cleanly in 25-30 minutes you're in good shape. Hards aren't required, but being comfortable with graph problems specifically (BFS/DFS, connected components, shortest path flavors) seems to matter here given their domain.
One thing I noticed: they cared a lot about clean code, not just getting to an answer. My interviewer explicitly said Dropbox values readability. So don't just dump a working solution, talk about how you'd refactor it.