ok so i just finished j&j's online assessment (oa) for a software engineer role on their consumer health tech side. sharing because i found almost nothing useful when i searched for this before going in.
platform: hackerrank. they gave me a 5-day window to complete it, with 90 minutes once started. i did it on a tuesday afternoon which felt less stressful than cramming it into the weekend.
structure: 2 coding problems. that's it. no mcq, no debugging questions, no sql. just the two problems.
difficulty: both were medium in my assessment. not easy, but not hard either. problem 1 was essentially an array manipulation problem. find the subarray meeting some condition. standard sliding window territory. problem 2 was graph-related. bfs or dfs would both work. i went dfs because it felt more natural, worked fine.
no dynamic programming or tree problems showed up for me. i don't know if the problem set varies between candidates or not.
time: i finished both in about 55 minutes and used the remaining time to check edge cases. test cases included some nulls and empty inputs so definitely run through those.
what i'd do differently: i second-guessed myself on the graph problem and wasted 10 minutes switching approaches before going back to my first instinct. if your first read of the problem suggests a direction, try it before pivoting.
did i pass: yes, i got a recruiter call scheduled. the oa result came back in 4 business days. i was anxious the whole time but it worked out.
one thing worth noting: j&j sends a prep email before the oa that says 'be comfortable with data structures and algorithms at a mid-level'. that's accurate. they're not trying to weed you out with impossible problems on the oa. the harder filtering happens in the live panel.
if you're a new grad or early-career engineer, this should feel doable if you've done a couple weeks of solid leetcode prep focused on mediums. don't spiral on it.