A ground-up, no-jargon field guide to relational (SQL) and non-relational (NoSQL) databases — how each family works internally, why NoSQL was invented, and exactly how to decide which one your project actually needs. Covers all 20 sections: introduction and history (Codd’s relational model, Bigtable 2004, Dynamo 2007, the 2009 NoSQL…

A complete, beginner-to-advanced field guide to the four main types of NoSQL databases — Key-Value, Document, Column-Family, and Graph — explaining in plain English why NoSQL exists, how each family stores and moves data internally, and how to choose the right one for a real production system. Starts with a…

A complete beginner-to-production guide to key-value stores: the simplest, fastest kind of database, how it works internally from the hash table upward, how it scales to billions of lookups per second, and how to use it well in real systems. Covers 19 sections including introduction and history (Berkeley DB, Bigtable,…

A complete beginner-to-production guide to service choreography: what it is, how it differs from orchestration, and how independent microservices coordinate a full business process through events, an event bus, and the Saga pattern. Covers 22 topics including core concepts (event, broker, pub/sub, autonomy, decoupling, idempotency, event sourcing, eventual consistency, command…

A complete, beginner-friendly chronicle of the Saga pattern — how independent microservices keep a long, multi-step business promise together and gracefully undo it when one chapter of the story goes wrong. Starts with the wedding-planning analogy, then traces the pattern from its 1987 origin in the Garcia-Molina and Salem paper…

A first-principles, beginner-friendly guide to why traditional ACID transactions and the Two-Phase Commit protocol do not survive the jump from a single monolithic database to many independent microservice databases — and exactly how modern systems stay consistent using the Saga pattern (choreography and orchestration), the Outbox pattern, idempotency, and eventual…

A complete, book-quality guide to the Strangler Fig Pattern for legacy modernisation — coined by Martin Fowler in 2004 and now the de-facto way to migrate a monolith to microservices without a risky big-bang rewrite. Nineteen chapters cover history, motivation, core vocabulary (legacy system, facade, seam, anti-corruption layer), architecture, the…

A complete, beginner-friendly guide to service discovery — how hundreds of moving, restarting, scaling microservices find each other without anyone hand-writing an address book. Traces history from 1990s hardcoded IPs through AWS, the microservices boom, Netflix Eureka, HashiCorp Consul, Kubernetes DNS-based discovery, and the modern service-mesh era. Covers vocabulary, architecture,…

A complete, beginner-friendly guide to compensating transactions — the technique that lets microservices stay consistent when a step fails halfway through, from the 1987 Saga paper to modern orchestrators like AWS Step Functions, Temporal, Camunda, and Azure Durable Functions. Opens with the broken-toy order analogy (money taken, delivery slot booked,…

A complete, beginner-friendly guide to inter-service communication — the set of techniques, protocols, and patterns that let independently deployed microservices work together as one coherent application. Opens with the school-staff analogy (class teacher, librarian, canteen worker, sports coach, principal — none of whom can do everything alone) and the restaurant-kitchen…