PhonePe

Role: SDE (2 - 5 Years Experienced)

College: Not Specified

Interview Date: Not Specified

Interview Type: Not Specified

Result: Not Specified

Difficulty: Not Specified

Rounds: 4 rounds

Topics Asked: Machine Coding (Low-Level Design, Eviction Strategy), Data Structures, Algorithms, System Design (High-Level Design, Microservices, Scalability, API Failures), CS Fundamentals (OOPs, OS, DBMS, Computer Networks)

Experience:

This PhonePe interview experience for an SDE with 2-5 years of experience involved four rounds.

Round 1 was a Machine Coding Round. The task was to "implement the multilevel cache design." This involved a system with L1 to Ln levels, storing Key-Value pairs (both String type). Key configurations included the maximum number of cache levels (starting with 1 and growing), and a fixed capacity for each level (though capacities could differ per level). Read operations start from L1, moving to the next level if the key is not found, and writing the value to L1 if found at any level. Write operations start from L1; if a level is full, a key-value pair is evicted and written to the next level, potentially adding a new level if the last one is full. Deletes involve removing the given key from all levels where it's present. The eviction strategy needed to be pluggable.

Round 2 was a DS Algo Round, where two problems were asked. Details of the specific problems were not provided in the snippet.

Round 3 was a Design Round focused on System Design. The problem was to "Design a flight aggregator system." This required a high-level design covering how the aggregator would obtain data from different airlines, store it in its database, and allow users to search and book flights. Specific considerations included segregating the system into different microservices, handling high traffic on the search API, showing connecting flights if no direct ones are available, and managing booking across different airlines and API failures.

Round 4 was a HR/Technical Round. While not detailed in this specific experience, other experiences indicate this round often includes behavioral questions, project discussions, and sometimes technical questions on past experience or general CS fundamentals like OOPs, OS, DBMS, and Computer Networks.