Paytm Interview Experience [SDE-2] (F2F)

Round 0: Online Assessment (HackerRank)

• Duration: 63 minutes
• Format:
  • 2 Coding Questions (Easy–Medium level):
    1. Find the number of common subsequences which are substrings of one of the strings.
    2. Find the maximum even sum from a given list of numbers.
  • 6 MCQs on DSA concepts and problem-solving techniques.

Result: Selected for next round.

Round 1: Technical + System Design (F2F)

• Project Discussion:
  Deep dive into my last project, tech stack used, and reasoning behind the choices.

• System Design Discussion:

  • Problem statement: Design a service similar to ClearTrip with premium members features.
  • Topics covered: load balancing algorithms, auto-scaling, DB sharding, health monitoring, and scaling thresholds.

• LLD (Low-Level Design):

  • Task: Implement a calculateETA feature based on vehicle type.
  • Discussion on which design patterns to use and how the service class structure would look.

Outcome: Selected for next round.

Round 2: High-Level Design (F2F)

• Introduction: Strengths and weaknesses discussion.

• HLD Discussion:

  • Task: Design Paytm Risk Management Service (distributed system) on whiteboard.

• Database Focus:
  Schema design and query performance optimization.

• Interview Experience:
  The interviewer was less cooperative; expectations were unclear.
  Unlike most candidates (who faced a DSA-focused 1st round), both my rounds were system design heavy.

Outcome: Rejected.

Takeaway

• The process heavily depends on the interviewer.
• Some candidates face more DSA-focused rounds, while others (like me) get deep system design rounds.