Easy Learn
A complete, beginner-to-production tutorial on the correlation ID — a short, unique, opaque string (usually a UUID like 7f3a9e21-4b6d-4c2a-9f11-8e2d5c7a10bb) attached to a request at the moment it enters a system and then propagated unchanged through every service, message queue, database call and log line that touches it, so a single…
A complete, beginner-to-production tutorial on service versioning — the practice of labelling distinct editions of an API or service so that old and new clients can both keep working while the service itself evolves. Opens with the toy-robot-and-remote analogy (an old remote that only knows “walk” is exactly the same…
A beginner-to-production field guide to the modular monolith: a single deployable application internally organised into clearly bounded modules, each owning its own business capability, its own data, and its own public interface. Covers the full evolution from Big Ball of Mud through layered enterprise architecture, the 2011–2015 microservices wave, the…
A beginner-friendly, production-grade tutorial that explains the modular monolith pattern from first principles and answers the single most common architecture-interview question — why experienced teams often choose a modular monolith over jumping straight to microservices. Opens with the house analogy (Big Ball of Mud monolith = one giant room; modular…
A beginner-to-production field guide to the Domain Events pattern in microservices: what a domain event is (a past-tense fact like OrderPlaced, PaymentReceived), how it differs from commands and queries, why it powers loose coupling in event-driven architecture, and the full supporting cast — aggregate roots, message brokers (Kafka, RabbitMQ, EventBridge,…
A ground-up, from-zero-to-production tutorial that compares SQL (relational) and NoSQL databases side by side. Starts with the shop-notebook analogy and a short history — Codd’s 1970 relational paper, Oracle (1979), MySQL and PostgreSQL, the ANSI SQL standard (1986), Google’s Bigtable (2006), Amazon’s Dynamo (2007), the rise of MongoDB, Cassandra, Redis…
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…