Short HLD trade-offs between monoliths and microservices.
Pattern notes: when to use fixed-size vs variable-size sliding windows.
Notes on load balancing strategies and when to use sticky sessions.
Find pair summing to target using a hashmap; common interview pattern.
Short HLD notes for a cache layer: eviction, TTL, and cache coherency trade-offs.
Quick notes on hash table basics, collision handling and use-cases.
