Hello,
I've interviewed for a Senior Software Engineer position at Bloomberg a couple of weeks ago.

Recruiter call with usual content of these calls, what the interview process consits of etc..

Phone interview:
Some chat about previous work and current company.
https://leetcode.com/problems/number-of-islands/
Followed up by https://leetcode.com/problems/unique-paths-ii/
I got through both of these fairly quickly as I've trained a lot of LC problems, communicated well and expressed my thought process, debugged by reading code and use an example before saying I was done and/or running the code. I then ran those and apart from a very very minor mistake, result was correct right away.

About 2 hours later I got an email from the recruiter saying congrats the team wants to move to onsite.
Interviewer was really great, smart and chill.

Virtual Onsite:
About two weeks after the phone interview came the onsite.
I had two tech interviews that day, and if I pass I would have manager and HR interviews the next day.

Onsite tech 1:
Two interviewers join, from the two teams I was interviewing for.
Had a fairly pleasant chat about my work, and theirs, a couple of questions like difference between frameworks, some software engineering discussions, Why Bloomberg etc..
Last 30 mins they asked me a variation of (https://leetcode.com/problems/two-sum/), I believe the difficulty of the modified version of that problem is LC 'medium'.
Again asked some clarifying questions (duplicates, negative numbers etc..), stated the brute force solution and its runtime, then suggested a faster better solution, coded it, found and fixed some bugs, the interviewer spotted a bug and told me he has identified an issue, but before telling me it I was going through my code with an example and found it myself, which was positive point.
The interviewers asked me if I had any questions, I did, we talked for a few mins then they left and two other interviewers joined for the second round.

Onsite tech 2:
Two other interviewers joined, also had some tech discussions, about tools we use for monitoring and observability in my work, and stuff like that. Then came time for the coding question, they asked me a coding question relative to the programming language that was needed for the position (and my most proficient prog language), I recognized the pattern and suggested a plan for the code solution, it was a bit tricky, as even though I use this language daily and have been for years, it's a paradigm that isn't that usual to find in code bases or use etc..
It took me about 30 mins to finish it up, had to run twice or so, interviewers gave very minor hints, but the solution worked at the end and gave correct result. (code wasn't very elegant, but it was a tricky question)
At the end, they asked me if I had any questions, talked a bit and that was it.

About two hours later I get an email saying team didn't want to move on, had a call with the recruiter a few days later for feedback.
Feedback was ok, and fair. And was told that the second onsite tech interview took me a bit more to solve than what other accepted candidates took. Was told that the team I was applying for is very picky; I can apply for another position.

Tips and takeaways:

• Do company tagged problems (Learn the problem solving pattern and not only the specific solution to the problem)
• Read discussion posts about the company here on LC and on Glassdoor (Gives lots of insights on the process, problems to train on, questions to prepare etc..)
• Have the feedback call after rejection, lots of insights on areas to improve that are in your blind spot, that can also help with interviews at other companies.
• Write clean code for your solutions, split to functions, and use clear names for functions and variables.

And finally don't let rejection get to you, sometimes it really depends on luck, and companies are very picky and need you to have the perfect clean coded solution fairly quickly.