Crawler Log Folder
A easy-tier problem at 72% community acceptance, tagged with Array, String, Stack. Reported in interviews at Mercari and 3 others.
Crawler Log Folder is an easy problem that shows up across multiple companies including Mercari, ZS Associates, Flipkart, and Atlassian. You're tracking a file system crawler's position as it receives commands to navigate folders. It sounds trivial but trips people up because they overthink the data structure or mishandle the root edge case. With a 71.6% acceptance rate, most candidates pass, but the ones who blank or second-guess themselves burn interview time. If this hits your live assessment and you freeze on the trick, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Crawler Log Folder"
Crawler Log Folder is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoderThe problem wants you to simulate a file system navigator. You get a list of commands: go to parent folder '..', stay put '.', or enter a subfolder. Track the depth (how many folders deep you are). The catch isn't the algorithm, it's the implementation. Most candidates reach for a stack or a counter, and both work, but a counter is cleaner since you only care about depth, not the actual path. The real pitfall is the root boundary: you can't go above the root, so every '..' needs a guard. Since 71.6% of submissions pass, the problem isn't hard, but if you've never seen it and you're tired during the real OA, you might muddle the logic. That's where the hedge matters most. This appears alongside Array, String, and Stack topics, though honestly you don't need a stack at all.
Pattern tags
You know the problem.
Make sure you actually pass it.
Crawler Log Folder recycles across companies for a reason. It's easy-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Crawler Log Folder interview FAQ
How hard is Crawler Log Folder really?+
It's easy. 71.6% acceptance. The concept is simple: count depth. But 'easy' on LeetCode doesn't mean bulletproof in a live OA. The root boundary and the string parsing are where careless mistakes hide. If you're tired or rushing, you slip. That's the real risk.
Why does ZS Associates ask this?+
ZS is one of four companies in the data asking this. They and Atlassian, Flipkart, and Mercari all report it. File system or file-like navigation logic is common in backend and systems work. It's a soft check for your ability to handle state and edge cases cleanly.
Do I need a stack?+
No. A counter works perfectly. You only care about depth, not the actual folder names. A stack is overkill and slower. The topics mention Stack, but that's a red herring. Keep it simple: track depth, increment on folder entry, decrement on '..' (but not below 0).
What's the edge case that breaks people?+
The root folder. If you're at depth 0 and you see '..', you stay at depth 0, you don't go negative. Every candidate nods along until they test it. Then they panic and add a conditional check they should've written first.
Is this still being asked at FAANG-adjacent companies?+
Yes. Mercari, ZS, Flipkart, and Atlassian all report it. It's not a flashy problem, but that's exactly why it shows up. Companies want to see if you can code something straightforward without fuss under pressure.
Want the actual problem statement? View "Crawler Log Folder" on LeetCode →