OCI | SMTS | Interview experience | Oracle

YOE: 5
Applied on job portal and recruiter reached out to me.

Screening round:
    - Discussion on the current project (40 mins)
    - Problem solving : https://leetcode.com/problems/avoid-flood-in-the-city/description/ (30 mins)


4 Loops interviews were scheduled back to back after 2-3 days

Round 1: Problem solving
    1. Remove Binary trees leaves step by step from left to right until the whole tree becomes empty
    -

Input: root = [1,2,3,4,5]
Output: [[4,5,3],[2],[1]]
    2. https://leetcode.com/problems/remove-k-digits/description/


Round 2: Design a chat application similar to whatsapp/slack (1 hr)
    - 1B users, 10M DAU
    - Discussion on API Design, DB choices, guaranteed message delivery


Round 3: Hiring manager (45 mins)
    - Deep dive into the current project, work experience and some follow-ups.
    - Behavioural questions
        1. Most critical bug
        2. What have done to increase the productiivity of the team

Round 4: Problem solving and distributed systems (1hr 15 mins)
    1. Some question on binary search similar to: https://leetcode.com/problems/koko-eating-bananas/description/
    2. Question on stack similar to finding the next greater element
    - Distributes system questions.
      - SQL vs NoSQL
      - DB indexing
      - Scalability at each layer

Update:
Verdict: Rejected as I was unable to provide the working solution for 1st problem in round 1