API Design
REST API design best practices — resource naming, HTTP methods, status codes, pagination, versioning, authentication, rate limiting.
Authentication & Authorization
Auth architecture — OAuth 2.0, OIDC, JWT, session tokens, RBAC vs ABAC, 2FA, SSO, and common auth vulnerabilities.
Caching Strategies
Cache patterns and eviction policies — cache-aside, read-through, write-through, write-behind, Redis, Memcached, and CDN caching.
Capacity Planning
Capacity planning for distributed systems — load forecasting, bottleneck analysis, Little's Law, back-of-the-envelope estimation, scaling strategies, and cost opt.
CDNs Explained
Content Delivery Networks — edge caching, origin shield, cache purging, Anycast routing, Cloudflare vs Fastly vs CloudFront.
Circuit Breaker Pattern
Circuit breaker pattern for resilient distributed systems — prevent cascading failures with closed/open/half-open states, thresholds, fallbacks, and real-world im.
Consensus Algorithms
Complete reference for distributed consensus algorithms — Raft, Paxos, and PBFT explained with leader election, log replication, safety guarantees, and real-world.
Data Replication Strategies
Database replication patterns — leader-follower, multi-leader, leaderless, synchronous vs asynchronous, conflict resolution, and failover strategies.
Database Indexing
Database indexes explained — B-Tree vs Hash vs GIN vs GiST, composite indexes, covering indexes, and index optimization.
Database Scaling
Database scaling strategies — read replicas, connection pooling, vertical vs horizontal, caching layers, denormalization.
Database Sharding
Database sharding strategies — horizontal partitioning, shard keys, consistent hashing, resharding, and cross-shard query handling.
Distributed Transactions
Distributed transactions guide — two-phase commit, Saga pattern, compensating transactions, eventual consistency patterns, and how to maintain data consistency ac.
Edge Computing Architecture
Edge computing architecture and patterns — CDNs, edge functions, IoT gateways, fog computing, data locality, and the trade-offs between edge and cloud processing.
Event-Driven Architecture
Event-driven architecture patterns — event sourcing, CQRS, pub/sub, event buses, dead letter queues, ordering guarantees, and when to choose events over request-r.
Fault Tolerance Patterns
Fault tolerance patterns for highly available systems — redundancy, retry with backoff, bulkheads, timeouts, failover, load shedding, graceful degradation, and ch.
GraphQL vs REST
GraphQL fundamentals — queries, mutations, subscriptions, resolvers, N+1 problem, DataLoader, and when GraphQL beats REST.
Idempotency Patterns
Idempotency patterns for distributed systems — exactly-once semantics, idempotency keys, deduplication strategies, HTTP idempotency, and database techniques to pr.
Logging Best Practices
Structured logging guide — JSON logging, log levels, correlation IDs, sampling strategies, sensitive data handling.
Message Queues
Message queues and event streaming — Kafka vs RabbitMQ vs SQS, pub/sub patterns, dead letter queues, exactly-once semantics.
Microservices Patterns
Microservices architecture — service discovery, API gateway, circuit breaker, saga, CQRS, event sourcing, Strangler Fig.
Monitoring & Observability
Observability stack — metrics, logs, traces, Prometheus, Grafana, OpenTelemetry, alerting strategies, SLOs, error budgets.
Rate Limiting
API rate limiting strategies — token bucket, leaky bucket, fixed window, sliding window log, distributed rate limiting with Redis.
REST API Best Practices
Advanced REST API patterns — HATEOAS, content negotiation, ETags, idempotency keys, batch operations, and hypermedia controls.
SQL vs NoSQL
Choosing between SQL and NoSQL — ACID vs BASE, relational vs document vs key-value vs graph, decision framework.
System Design Basics
Core system design concepts — scalability, availability, reliability, CAP theorem, consistency patterns, and fundamental trade-offs.