System Design

RPC framework architecture: IDL/contracts, serialization, transport, multiplexing, discovery, load balancing, timeouts, retries, observability, and compatibility.

Fixed/sliding windows, token and leaky buckets, distributed rate-limit state, fairness, burst handling, local/global layers, and failure behavior.

Public API contracts, authentication, authorization, idempotency, versioning, errors, pagination, quotas, signatures, observability, and backwards compatibility.

Deadline propagation, timeout budgets, retry safety, exponential backoff/jitter, retry storms, idempotency, hedging, and observability.

Stable error taxonomy, machine-readable codes, retryability, user-facing messages, wrapping/context, cross-service mapping, and observability.

A general model for thread, connection, object, and worker pools: lifecycle, sizing, queue bounds, validation, fairness, and overload behavior.

Cache layers, cache-aside/read-through/write-through/write-back, consistency races, invalidation, stampedes, penetration, hot keys, TTL, and source-of-truth recovery.