Experience: 6.5 years
Position: E4/E5
Location: London, UK
Interview Date: Feb-March 2022
Result: Awaiting

I got a call from Recruiter of Meta during the month of December. As I was not looking actively, I asked her for 15 day preparation before appearing for the screening rounds.
Finally, in second week of January, I appeared for Technical Screening.

[Wont reveal the exact questions but tags around it]
Screening Round - (45 minutes)

1. LC medium related to BFS Tree traversal. I was able to solve it with optimal solution. There is also a follow up Hard question but he didnt ask that.
2. LC medium related to Array and Probablity. I was stuck once but was able to solve it without hint.

Result: Passed. Both the questions were from FB tagged Top 100 questions.

After that, I had a call with recruiter who explained me the next steps. She advised for 4 weeks of preparation so we scheduled the rounds during Feb 16-23

OnSite Technical: (45 minutes)

1. LC medium. Problem related to String, Stack, Arithmetic Ops. Was able to solve it but then got follow up question to solve in O(1) space. After some thought, I was able to tell the solution but dint code in interest of time.

2. Problem with relevant tags: DFS, Union Find, Flood Fill, 2D Arrays, Matrix. I would say it was a bit harder version of LC medium hence this was LC hard category but I was able to solve it. 1 utility function was not coded(pretty trivial) but the round went well.

From my perspective, this round went well.

OnSite Technical: (45 minutes)

1. LC Hard related to Numbers and String Manipulation with some tweaks. Interviewer asked to check if I had covered all the edge cases. As this problem tends to have multiple edge cases, I wrote down the edge cases first and then started coding. Was able to solve it. Not aware if I missed any edge case.
2. LC medium related to Tree and LCA (again with different scenario wrapped around it), once you decoded the question, the answer was pretty straight forward.
   Not aware from interviewer's perspective but I was able to solve both and had 5 minutes remaining where I asked a couple of questions related to work culture and all.

Design Round: (45 minutes)
I think I messed up a bit here. The problem statement came from the common topic but I had not prepared. Also, the interviewer was not interested in overall design. He just wanted me to focus on one specific module/service and how would I design it. He was not interested in Load Balancers, APIs, and overall architecture.
I believe I had a pretty mediocre round.

Behavioral Round(s):

I had 2 behavioral rounds. One was just for interviewer's practice I guess. It was not graded which I came to know later. These rounds went well from my perspective. This was the most unprepared round that I gave.

After a week, I received an email from recruiter and the next day we had a call. She explained me that they received my feedback but I needed to give a follow-up behavioral round. As they were not able to get signal from the behavioral rounds.

Follow Up Behavioral Round 3 (45 minutes)
I gave the final behavioral round in second week of March. As I had a week's time, I prepared the common leadership questions pretty well.
This round went extremely well. The interview even discussed the possiblity and process of relocation, the work culture. How the work differs from India and UK etc.

Since this round, I am waiting for results. My recruiter contacted me this week(last week of March 2022) and informed me, that she will get update next week.

I just want to say that, unlike all the posts I see here, which aspire us to study and prepare daily, I gave the rounds intuitively. I hardly solved 80 Easy, 100 Medium questions and 20 Hard questions on LC. My prepartion was only from screening rounds to OnSite rounds. I always believed in my intuitive approach to solve a question.

But I am happy I was able to face the OnSite technicals pretty well and the Behavioral rounds also went well. My only concern is the Design round. Hopefully, I would get the result soon.

Does anyone know what the FB follow-up round means? And where I would be in the interview process? Or have I already been rejected and just waiting for the feedback to come that way? I have no idea.
Thank you LC community, my 90% preparation for technicals was from LC and 10% from youtube.