Core CS Concepts
Operating Systems, Networking, and DBMS/NoSQL fundamentals — the theory questions that show up in every SDE 2 interview loop, alongside DSA and system design.
Operating Systems
Process vs thread, scheduling algorithms, memory management, paging, deadlocks, synchronization, IPC
Networking
OSI/TCP-IP model, TCP vs UDP, handshake, HTTP versions, DNS resolution, load balancing, CDN
DBMS & NoSQL
ACID vs BASE, normalization, indexes, isolation levels, SQL vs NoSQL, NoSQL data modeling questions
// How Core CS Questions Show Up
Interviewers often open with 2-3 quick theory questions (e.g. 'difference between process and thread', 'TCP vs UDP') before moving to coding — used as a warm-up filter.
'Why did you choose eventual consistency here?' or 'How would a hash index help this query?' — CS fundamentals justify your system design trade-offs.
'Your API is slow under load — what could cause it?' expects context-switching, connection pool exhaustion, lock contention, or index-related answers.
Given at SDE 2 level: 'design the schema for X in MongoDB/Cassandra' — tests whether you understand denormalization trade-offs, not just syntax.