Performance Bottlenecks

ADO.NET connection pooling and pool exhaustion

Explains physical connection reuse, pool partitioning, short ownership, exhaustion causes, diagnostics, and why increasing the pool is not the first fix.

ASP.NET Core output caching vs HTTP response caching

Compares server-controlled output caching with HTTP cache semantics and defines safe keys, variation, invalidation, identity, and multi-instance behavior.

Build a JPA projection query with optional filters

Builds a bounded dynamic query that returns a read model, applies only supplied predicates, and uses deterministic ordering.

Cache API responses versus domain objects

Compares caching response-shaped read models with caching domain entities or raw database objects.

Choose a TTL and expiration strategy for cached data

Explains how TTL choices balance freshness, load reduction, user expectations, and operational safety.

Coalesce concurrent Java loads for the same key

Implements single-flight request coalescing so one load runs per key while unrelated keys remain concurrent.

Distributed Caching & Redis

Redis, cache-aside, invalidation, sessions, stampedes, and cache operations.

A practical backend track covering distributed caching with Redis, cache-aside reads, TTLs, invalidation, key scope, stale data, sessions, stampedes, Redis outages, locks, rate limiting, memory pressure, and production observability.