Round 1: Machine coding
1.5 hrs

1. Handle multiple communication request types (Email, SMS, Soundbox, etc.).
2. Different request types have different mandatory input fields (e.g., Email: sender, receiver, subject, message; SMS: mobile number, message)
3. Providers can support one or multiple channels; multiple providers per channel allowed.
4. Each provider can have multiple accounts, segregated for better handling (e.g., critical OTP communication).
5. Randomly select one active provider from eligible providers for each request.

Round 2: PS/DS
1)https://leetcode.com/problems/remove-k-digits/description/
2)https://codeforces.com/problemset/problem/1037/D

Round 3: HLD
Design Instagram
Note: For feed publishing and fetching, Interviewer didn't agree with Message queue approach as it is not scalable for billions of users.

Round 4: HM
Project discussion

Verdict: Selected

Compensation: https://leetcode.com/discuss/post/6592499/phonepe-backend-sde-3-yoe-offer-by-anony-cpxy/