| ADR | Architecture Decision Record — a short document capturing a significant architectural decision, its context, and its consequences |
| ATAM | Architecture Tradeoff Analysis Method — a structured SEI methodology for evaluating architectural decisions against quality attributes |
| Atomic Design | Brad Frost's design system methodology organizing components into atoms, molecules, organisms, templates, and pages |
| BFF | Backend for Frontend — a dedicated backend service shaped specifically for one UI client (web, mobile), owned by the frontend team |
| Bounded Context | DDD concept: an explicit boundary within which a specific domain model and ubiquitous language applies consistently |
| C4 Model | Simon Brown's four-level architecture documentation model: Context, Container, Component, and Code |
| CLS | Cumulative Layout Shift — Core Web Vital measuring visual stability; target ≤ 0.1 |
| CRDT | Conflict-free Replicated Data Type — a data structure enabling conflict-free concurrent updates in distributed systems (Yjs, Automerge) |
| CSP | Content Security Policy — HTTP response header that instructs browsers to restrict sources of executable scripts and other resources |
| CSR | Client-Side Rendering — HTML rendered by JavaScript in the browser; no server-rendered HTML |
| Conway's Law | Organizations design systems that mirror their own communication structure |
| DDD | Domain-Driven Design — an approach to software development that models software around the business domain |
| DACI | Driver, Approver, Contributors, Informed — a decision-making framework clarifying roles in a decision |
| FCP | First Contentful Paint — time until the first content element is painted in the browser |
| FSD | Feature-Sliced Design — a framework-agnostic frontend codebase organization methodology with six hierarchical layers |
| Fitness Function | An automated test that verifies an architectural property of the system (no circular dependencies, bundle size under budget) |
| GraphQL | A query language for APIs and a runtime for executing queries with your data |
| INP | Interaction to Next Paint — Core Web Vital measuring input responsiveness; target ≤ 200ms |
| ISR | Incremental Static Regeneration — Next.js rendering pattern that serves a cached static page while regenerating it in the background |
| iSAQB | International Software Architecture Qualification Board — German-origin certification body for software architects |
| LCP | Largest Contentful Paint — Core Web Vital measuring loading performance; target ≤ 2.5s |
| MFE | Micro-Frontend — an independently developed and deployed frontend application module; extends microservices model to the UI |
| MQTT | Message Queuing Telemetry Transport — lightweight pub/sub protocol for IoT device communication |
| NFR | Non-Functional Requirement — quality attributes such as performance, security, scalability, and accessibility |
| OCPP | Open Charge Point Protocol — industry standard protocol for EV charging station communication |
| OT | Operational Transformation — algorithm enabling real-time collaborative editing (used by Google Docs) |
| PKCE | Proof Key for Code Exchange — OAuth 2.1 security extension mandatory for all authorization code flows |
| Ports and Adapters | Also called Hexagonal Architecture: ports are interfaces, adapters are implementations — the application core depends on ports only |
| Progressive Enhancement | Building web experiences in layers: functional HTML, then CSS, then JavaScript — each layer optional |
| RADIO | Requirements, Architecture, Data, Interface, Optimizations — frontend system design interview framework |
| RFC | Request for Comments — a document proposing a significant technical change, circulated for team input before a decision is made |
| RSC | React Server Components — React components that execute on the server and send minimal HTML/JSON to the browser |
| SBI | Situation, Behavior, Impact — structured feedback framework |
| SPA | Single-Page Application — a web application loading one HTML page and updating dynamically via JavaScript |
| SRI | Subresource Integrity — a browser mechanism to verify that fetched resources have not been tampered with, using cryptographic hashes |
| SSE | Server-Sent Events — a web standard for unidirectional server-to-client streaming over HTTP |
| SSG | Static Site Generation — pre-rendering all pages to HTML at build time; served from CDN |
| SSR | Server-Side Rendering — rendering the full HTML of a page on the server per request |
| STAR-L | Situation, Task, Action, Result, Learnings — behavioral interview framework with added learning dimension |
| Strangler Fig | A software migration pattern that incrementally replaces a legacy system route-by-route without a big-bang rewrite |
| Tech Radar | A visual tool (popularized by ThoughtWorks) classifying technologies into ADOPT, TRIAL, ASSESS, and HOLD rings |
| tRPC | TypeScript Remote Procedure Call — end-to-end type-safe API layer for full-stack TypeScript applications |
| TTFB | Time to First Byte — the time from a browser request until the first byte of the server response is received |
| Ubiquitous Language | DDD concept: a shared vocabulary used consistently by developers and domain experts within a Bounded Context |
| Virtualization | Rendering only the visible items in a long list (windowing) — used for lists of hundreds or thousands of items |
| WCAG | Web Content Accessibility Guidelines — international standard for web accessibility; version 2.2 is the current target |
| XSS | Cross-Site Scripting — a category of injection attack where malicious scripts are injected into web pages viewed by other users |