Did the Mars online assessment this week for a software engineer role on their digital team. Posting fresh because I searched forever and found almost nothing recent.
Platform: HackerRank. Two hours, two problems.
Problem 1 String/array manipulation. Not a classic LeetCode problem I recognized but the pattern was similar to medium-difficulty prefix sum or frequency map questions. Honestly probably LeetCode medium if I had to classify it. Completed in about 30 minutes.
Problem 2 This one was more domain-flavored. Something about inventory or order processing (they make it feel relevant to their business). Algorithmically it was two nested loops with a potential optimization to bring it down to O(n log n). I got a correct solution but not the optimal one within time and it still passed all test cases because their test data wasn't large enough to expose the quadratic complexity.
Time pressure Two hours for two problems felt reasonable. I wasn't scrambling at the end. But I know people who said they ran out of time, so maybe practice under a clock if you're the type to over-explain your code comments.
What I wasn't expecting No SQL section. No system design. No behavioral. Just coding. I expected maybe some multiple choice but nope. Pure algorithm problems.
After the OA Got an email five business days later that I was moving to the phone screen. They didn't give feedback on my OA score, which is normal.
Overall: harder than what I expected from a CPG company but easier than anything I've done for Big Tech. If you've been grinding Leetcode mediums you should be fine. Hards not required.