Architecture terms
The decisions that outlive the code that implements them
Software architecture is the set of decisions that are hard to reverse and expensive to get wrong. This category covers design patterns, structural patterns like microservices and event-driven systems, domain-driven design, scalability principles, and the trade-offs that shape how large systems are built and evolved over years. Good architecture does not happen by accident.
Consistent Hashing
A hashing technique used in distributed systems where adding or removing a node rebalances only a fraction of keys rather than remapping everything — essential for distributed caches, load balancers, and sharded databases.
2mo ago
architecture advanced
CRDTs — Conflict-Free Replicated Data Types
Data structures designed to be replicated across multiple nodes where concurrent updates are automatically merged without conflicts — no coordination or consensus required, enabling high availability with eventual consistency.
2mo ago
architecture advanced
Leader Election in Distributed Systems
A coordination protocol where distributed nodes agree on a single 'leader' that takes responsibility for a specific task — preventing multiple nodes from performing the same action simultaneously (duplicate work, split-brain).
2mo ago
architecture advanced
Raft Consensus Algorithm
A consensus algorithm designed to be understandable — Raft elects a leader who coordinates all writes, replicates log entries to followers, and ensures that committed entries are never lost even when servers fail.
2mo ago
architecture advanced
Vector Clocks — Distributed Causality
A vector clock is a data structure — one counter per node — that tracks causal ordering of events across distributed nodes without a shared clock, enabling detection of concurrent events and causal relationships.
2mo ago
architecture advanced
Aggregate Design Heuristics PHP 7.0+ Rules for sizing aggregates correctly — small aggregates with single-entity transactions, referencing other aggregates by ID, and designing boundaries around invariants not convenience.
2mo ago
architecture advanced
API Composition Pattern
An API layer aggregates parallel service calls into a single client response — reducing N round trips to 1 and improving perceived latency.
2mo ago
architecture advanced
Backends for Frontends (BFF) PHP 7.0+ A dedicated API layer per frontend client (mobile app, web app, third-party) — each BFF aggregates and transforms microservice data for its specific client's needs.
2mo ago
architecture advanced
Conformist Pattern
A context mapping relationship where the downstream team adopts the upstream team's model wholesale — accepting the upstream language rather than building a translation layer.
2mo ago
architecture advanced
Data Mesh Architecture
Decentralised data architecture where domain teams own and publish their data as products — replacing centralised data lakes that create engineering bottlenecks.
2mo ago
architecture advanced
Open Host Service & Published Language
A bounded context exposing a well-defined protocol (Published Language) for all downstream consumers — rather than custom point-to-point integrations for each.
2mo ago
architecture advanced
Ports & Adapters (PHP Worked Example) PHP 7.0+
Hexagonal Architecture in PHP — the application core exposes ports (interfaces), and adapters implement them for HTTP, CLI, databases, and external services.
2mo ago
architecture advanced
Read Model Projections Denormalised views of domain data built by processing event streams — the read side of CQRS, optimised for query performance rather than write consistency.
2mo ago
architecture advanced
Service Mesh Infrastructure layer handling service-to-service communication — mutual TLS, observability, retries, circuit breaking, and traffic shaping without application code changes.
2mo ago
architecture advanced
Shared Kernel
A DDD strategic pattern where two bounded contexts intentionally share a small subset of the domain model — requiring tight coordination between teams but reducing duplication.
2mo ago
architecture advanced
Sidecar Pattern
Deploying a helper container alongside the main application container in the same pod — extending functionality (logging, proxying, TLS) without modifying the application.
2mo ago
architecture advanced
Anti-Corruption Layer A translation layer between two systems with different models — preventing a legacy or external system's concepts and terminology from leaking into the domain model.
2mo ago
architecture advanced
Bounded Context (DDD) An explicit boundary within which a domain model and its ubiquitous language apply — the same term may mean different things in different contexts.
2mo ago
architecture advanced
Bulkhead Pattern Isolating system components into separate resource pools so a failure in one doesn't cascade and exhaust resources for others.
2mo ago
architecture advanced
CAP Theorem PHP 5.0+ A distributed system can guarantee only two of three simultaneously: Consistency, Availability, Partition Tolerance — driving fundamental design trade-offs.
2mo ago
architecture advanced