Did the full Target SWE loop earlier this year. Going to write up the coding rounds specifically because the OA format surprised me and I couldn't find good info beforehand.
For senior SWE roles, at least in my experience (backend, Minneapolis HQ-aligned), the process was: A CodeSignal OA. Two problems, 90 minutes. Both were medium difficulty on the LeetCode scale. One was a pretty standard BFS/DFS traversal with a retail twist (think: find shortest path in a store floor plan grid). The other was more of a design-and-implement thing where you had to write a small class with a few methods. It wasn't hard but the time pressure was real if you're rusty. A live coding round during the final virtual onsite. This one was paired with an interviewer on CoderPad. The problem was medium-ish. They were clearly watching how I communicated while coding, not just whether I got to the right answer. I talked through my approach, hit a bug, caught it, fixed it. They nodded along. Nobody wants a silent coder who just types.
LeetCode hard? No. I did not see any DP graph-theory nightmares. That said, if you only grind hards and haven't touched mediums in months, you might fumble the OA on time. The questions felt like they were written by engineers who actually work at Target, not recycled from a bank of leetcode clones.
One thing I'll add: the OA had a time component where they track how long you spend on each part. I don't know how much weight that has but just be aware.
Overall coding difficulty: solidly medium. Not a cakewalk but not a grind-200-leets-or-die situation. Know your arrays, trees, hashmaps, and basic graph traversal cold.