https://backendarchitect.com/ Clear guides to system design and backend engineering: a system design interview framework, caching strategies and rate limiting algorithms with code. en Mon, 28 Sep 2026 08:00:00 GMT https://backendarchitect.com/system-design-interview-framework/https://backendarchitect.com/system-design-interview-framework/Sun, 27 Sep 2026 08:00:00 GMTA step-by-step framework for system design interviews: clarifying requirements, estimates, APIs, data models, high-level design, deep dives and trade-offs. https://backendarchitect.com/caching-strategies/https://backendarchitect.com/caching-strategies/Sun, 27 Sep 2026 08:00:00 GMTCaching strategies and their trade-offs: cache-aside, read-through, write-through, write-back and write-around, plus eviction policies, TTLs and invalidation. https://backendarchitect.com/rate-limiting-algorithms/https://backendarchitect.com/rate-limiting-algorithms/Sun, 27 Sep 2026 08:00:00 GMTRate limiting algorithms compared: fixed window, sliding log, sliding window counter, token bucket and leaky bucket, with code and distributed design tips. https://backendarchitect.com/design-url-shortener/https://backendarchitect.com/design-url-shortener/Sun, 27 Sep 2026 08:00:00 GMTA URL shortener system design: requirements, capacity estimates, API, short-code generation, database choice, caching, analytics and scaling trade-offs. https://backendarchitect.com/sql-vs-nosql/https://backendarchitect.com/sql-vs-nosql/Sun, 27 Sep 2026 08:00:00 GMTSQL vs NoSQL explained: data models, consistency, scaling, query flexibility and when to use relational, document, key-value, wide-column or graph databases. https://backendarchitect.com/database-sharding/https://backendarchitect.com/database-sharding/Sun, 27 Sep 2026 08:00:00 GMTWhat database sharding is, when you need it, how to choose a shard key, range vs hash vs directory sharding, and the operational pain points to plan for. https://backendarchitect.com/consistent-hashing/https://backendarchitect.com/consistent-hashing/Sun, 27 Sep 2026 08:00:00 GMTHow consistent hashing works, why it beats modulo hashing when servers change, how virtual nodes balance load, and where it’s used in caches and databases. https://backendarchitect.com/kafka-vs-rabbitmq-vs-sqs/https://backendarchitect.com/kafka-vs-rabbitmq-vs-sqs/Sun, 27 Sep 2026 08:00:00 GMTKafka, RabbitMQ and Amazon SQS compared: log vs queue models, ordering, replay, throughput, delivery guarantees and operations, and when to use each. https://backendarchitect.com/cap-theorem-pacelc/https://backendarchitect.com/cap-theorem-pacelc/Sun, 27 Sep 2026 08:00:00 GMTThe CAP theorem and its extension PACELC explained: consistency, availability and partition tolerance, what the trade-offs mean in practice and common myths. https://backendarchitect.com/idempotency-keys/https://backendarchitect.com/idempotency-keys/Sun, 27 Sep 2026 08:00:00 GMTHow idempotency keys make retries safe: why duplicate requests happen, how to store and check keys, handling concurrent requests, expiry and common mistakes. https://backendarchitect.com/microservices-vs-monolith/https://backendarchitect.com/microservices-vs-monolith/Sun, 27 Sep 2026 08:00:00 GMTMicroservices or a monolith? The real costs and benefits of each, the modular monolith middle ground, and a practical framework for deciding and migrating. https://backendarchitect.com/load-balancing-algorithms/https://backendarchitect.com/load-balancing-algorithms/Sun, 27 Sep 2026 08:00:00 GMTLoad balancing algorithms compared: round robin, weighted, least connections, least response time, IP hash and consistent hashing, L4 vs L7 and health checks. https://backendarchitect.com/btree-vs-lsm-tree/https://backendarchitect.com/btree-vs-lsm-tree/Sun, 27 Sep 2026 08:00:00 GMTHow B-tree and LSM-tree storage engines work, why one favours reads and the other writes, write and read amplification, compaction and which databases use each. https://backendarchitect.com/design-notification-system/https://backendarchitect.com/design-notification-system/Sun, 27 Sep 2026 08:00:00 GMTHow to design a notification system for push, email and SMS at scale: requirements, architecture, queues, templates, preferences, retries and deduplication. https://backendarchitect.com/event-sourcing-cqrs/https://backendarchitect.com/event-sourcing-cqrs/Sun, 27 Sep 2026 08:00:00 GMTEvent sourcing and CQRS explained: storing events instead of state, separate read and write models, audit trails and replay, costs and when to use them. https://backendarchitect.com/design-chat-system/https://backendarchitect.com/design-chat-system/Mon, 28 Sep 2026 08:00:00 GMTHow to design a chat app: WebSockets, message flow and ordering, storage, group chat fan-out, presence, offline delivery and multi-device sync. https://backendarchitect.com/design-news-feed/https://backendarchitect.com/design-news-feed/Mon, 28 Sep 2026 08:00:00 GMTHow to design a social news feed: fan-out on write vs read, the celebrity problem, feed caches, ranking, cursor pagination and media delivery. https://backendarchitect.com/back-of-envelope-estimation/https://backendarchitect.com/back-of-envelope-estimation/Mon, 28 Sep 2026 08:00:00 GMTHow to do back-of-the-envelope estimates for system design: useful numbers, QPS, storage and bandwidth maths, latency orders of magnitude and a worked example. https://backendarchitect.com/database-indexing/https://backendarchitect.com/database-indexing/Mon, 28 Sep 2026 08:00:00 GMTHow database indexes work: B-tree and other types, composite and covering indexes, why queries ignore indexes, the write cost and checking with EXPLAIN. https://backendarchitect.com/database-replication/https://backendarchitect.com/database-replication/Mon, 28 Sep 2026 08:00:00 GMTDatabase replication explained: leader-follower, multi-leader and leaderless designs, sync vs async, replication lag, failover, quorums and conflict resolution. https://backendarchitect.com/transaction-isolation-levels/https://backendarchitect.com/transaction-isolation-levels/Mon, 28 Sep 2026 08:00:00 GMTACID and isolation levels explained: dirty reads, lost updates, write skew and phantoms, what each level prevents, database defaults and practical fixes. https://backendarchitect.com/rest-vs-grpc-vs-graphql/https://backendarchitect.com/rest-vs-grpc-vs-graphql/Mon, 28 Sep 2026 08:00:00 GMTREST vs gRPC vs GraphQL compared: how each works, performance, contracts, caching, streaming, tooling and browser support, and when each API style fits best. https://backendarchitect.com/cdn-explained/https://backendarchitect.com/cdn-explained/Mon, 28 Sep 2026 08:00:00 GMTHow CDNs work: edge locations, request routing, cache keys, Cache-Control headers, invalidation, origin shielding, security features and edge compute. https://backendarchitect.com/distributed-locks/https://backendarchitect.com/distributed-locks/Mon, 28 Sep 2026 08:00:00 GMTHow distributed locks and leases work, why process pauses break naive locks, fencing tokens, Redis, ZooKeeper, etcd and database locks, and alternatives. https://backendarchitect.com/saga-pattern/https://backendarchitect.com/saga-pattern/Mon, 28 Sep 2026 08:00:00 GMTThe saga pattern explained: local transactions and compensating actions, choreography vs orchestration, the outbox pattern and isolation pitfalls.