Implement cd(current_dir, new_dir) returning the absolute path, then add symbolic links
cd('/foo/bar', 'baz') is easy. cd('/foo/../', './baz') is where the OpenAI screen actually starts, and the symlink follow-up is where it ends. The stack solution plus the loop-guard most candidates forget.
Updated Sep 2026 · Grounded in real Forward Deployed Engineer interview loops and written to a senior-engineer editorial bar.
cd('/foo/bar', 'baz') is easy. cd('/foo/../', './baz') is where the OpenAI screen actually starts, and the symlink follow-up is where it ends. The stack solution plus the loop-guard most candidates forget.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
