Terminology

791 terms, tools, patterns and metrics an architect is expected to use precisely. Each one gets a short explanation of what it is, and — where it matters — what it is commonly confused with. Search filters as you type; the column headers sort.

All areas791 Architecture Fundamentals38 Distributed Systems73 Data Architecture71 Cloud Architecture55 Networking51 API & Integration Architecture45 Reliability & Resilience40 Observability33 Performance & Capacity Engineering34 Security Architecture50 Cost Architecture & FinOps30 Business Architecture28 Architecture Communication27 Enterprise Architecture27 Legacy Modernization27 AI-Era Architecture34 Software Architecture & Engineering37 Architecture Patterns34 Architecture Decision-Making30 The Architect's Meta-Skills27

Kind Any concept292 practice240 pattern133 metric36 protocol32 tool32 case-study26

791 terms shown.

Term	Kind	Topic	What it is
Split Brain	concept	Distributed Systems	A partition in which two halves of a cluster each believe they are authoritative, and both accept writes.
Split Vote	concept	Leader Election	An election in which no candidate obtains a majority, so the term ends with no leader and the process must repeat.
Spotify's Squad Model and Its Retrospective	case-study	Business Architecture	The widely-copied Spotify model of squads, tribes, chapters and guilds was a snapshot that did not work as documented even at Spotify — a caution about importing organisational design.
SQL vs NoSQL	concept	Architecture Decision-Making	A choice driven by access patterns, consistency requirements and query flexibility — not by data volume, which is the reason usually given.
Stakeholder Analysis	practice	Business Architecture	Identifying who is affected by an architecture, what each of them needs from it, and how much influence they have over whether it proceeds.
Standards Lifecycle	practice	Technology Standards	Managing technology standards through explicit states with review dates, so the standard set reflects current reality rather than past decisions.
Star Schema	pattern	Data Warehousing	A dimensional model with one central fact table of measurements surrounded by denormalised dimension tables describing them.
Stateful Packet Filtering	concept	Firewalls & Security Groups	Filtering that tracks connection state, so return traffic for an allowed outbound connection is permitted automatically.
Static Stability	concept	Reliability & Resilience	The property that a system keeps working on its existing state when its control plane or dependencies are unavailable, rather than needing them to keep running.
Step-Up Authentication	pattern	Authentication	Requiring stronger proof of identity at the moment a consequential action is attempted, rather than applying maximum friction to every session.
Storage Lifecycle Policy	practice	Storage Costs	Automated rules that move objects between storage classes as they age, matching cost to the declining probability that data will be read.
Storage Tiering	practice	Cost & FinOps	Moving data between access tiers as it cools, so rarely-read data is not paying hot-storage prices.
Strangler Facade	pattern	Strangler Fig	The routing layer in front of a legacy system that decides, per capability, whether a request goes to the old implementation or the new one.
Strangler Fig Strangler Pattern	pattern	Architecture Patterns	Replacing a legacy system incrementally by routing individual capabilities to new implementations behind a facade, until nothing routes to the old system.
Strategic Sourcing Decision	practice	Build vs Buy	A build-versus-buy decision framed around competitive differentiation and organisational capacity rather than a comparison of visible costs.
Stream-Table Duality	concept	Streaming Data	The equivalence between a stream of changes and a table of current state — each can be derived from the other.
Stress Test	practice	Stress Testing	Driving load beyond expected capacity to observe how the system behaves at and past its breaking point.
STRIDE	practice	Threat Modelling	A mnemonic for six threat categories — spoofing, tampering, repudiation, information disclosure, denial of service, elevation of privilege — walked across each component and data flow.
Stripe's API Versioning	case-study	API & Integration	Stripe pins each account to the API version current when it integrated and transforms requests and responses between versions internally, so integrations never break and the core stays modern.
Strong vs Eventual Consistency	concept	Architecture Decision-Making	A per-operation decision, not a per-system one: whether this specific read must reflect every completed write.
Structured Logging	practice	Observability	Emitting log entries as machine-parseable key-value records rather than as formatted prose.
Style versus Pattern	concept	Architecture Styles	The distinction between a system-wide organising structure and a reusable solution to a recurring problem within it.
Subject Naming Strategy	concept	Schema Registry	How schemas are keyed in a registry — per topic, per record type, or both — which determines whether one topic may carry several event types.
Subnet	concept	Networking	A subdivision of a network's address range, used as the unit of routing and, in cloud, of availability-zone placement.
Subnet Sizing	practice	Subnetting	Choosing subnet prefix lengths with enough headroom, given that subnets cannot be resized and cloud providers reserve several addresses in each.
Surrogate Key Synthetic Key	concept	Relational Modelling	A system-generated identifier with no business meaning, used as the primary key instead of a naturally occurring business value.
Sustainable On-Call	practice	On-Call	An on-call arrangement whose alert volume, rotation size and compensation allow it to continue indefinitely without degrading the people in it.
Symptom-Based Alerting	concept	Alerting	Alerting on degradation the user experiences rather than on the internal conditions that might cause it.
Synchronous vs Asynchronous Communication	concept	Architecture Decision-Making	Whether the caller waits for the callee's answer — decided by whether the caller's outcome depends on it, not by latency or taste.
Synchronous vs Asynchronous Replication	concept	Replication	Whether a write is acknowledged only after a replica has it, trading write latency against the amount of data a failure can lose.
System Context Boundary	concept	Context Diagrams	The line separating what a project owns and can change from what it must integrate with and accept as given.
Systems Thinking	practice	Meta-Skills	Reasoning about a system in terms of the interactions and feedback loops between its parts, rather than the parts individually.
Tabletop Exercise	practice	Game Days	A discussion-based walkthrough of a hypothetical incident that tests procedures and decision-making without touching any system.
Tagging Strategy	practice	Cloud Governance	A defined, enforced set of metadata labels applied to every resource, without which cost allocation, ownership and lifecycle automation are all impossible.
Tail Latency p99, p999	metric	Performance & Capacity	The latency experienced by the slowest small percentage of requests, which is what users and dependent services actually feel.
Tail-Based Sampling	pattern	Sampling	Deciding whether to retain a trace after it completes, so that slow and failed traces are kept while routine successful ones are discarded.
Tamper-Evident Log	pattern	Auditability	An audit log constructed so that any modification or deletion of past entries is detectable, typically by chaining entries cryptographically.
Target Tracking Scaling	pattern	Autoscaling	An autoscaling policy that adds or removes capacity to hold a chosen metric near a target value, like a thermostat, rather than reacting to threshold breaches.
TCP Handshake	protocol	TCP/IP	The three-way SYN / SYN-ACK / ACK exchange that establishes a TCP connection, costing one round trip before any data moves.
TCP/IP	protocol	Networking	The layered protocol suite underneath essentially all application traffic — IP routes packets, TCP turns them into a reliable ordered stream.
Team Interaction Mode	concept	Team Topologies	The defined way two teams work together — collaborating, consuming a service, or facilitating — chosen deliberately and expected to change over time.
Team Topologies	concept	Conway's Law	A model of four team types and three interaction modes used to design an organisation deliberately for a target architecture and flow of change.
Technical Debt	concept	Software Architecture	The future cost incurred by choosing an expedient implementation now instead of the better one.
Technical Depth Calibration	practice	Presenting to Engineers	Matching the level of detail and the mode of engagement to an engineering audience, which needs reasoning and the opportunity to disagree.
Technical Leadership	concept	Technical Leadership	Setting technical direction and raising the capability of others through credibility and clarity rather than through positional authority.
Technical Proposal Design Doc, RFC	practice	Architecture Communication	A written argument for a course of action, circulated for review before the work starts, structured so that disagreement surfaces early and cheaply.
Technical Proposal Structure	practice	Technical Proposals	An arrangement for a written design proposal that lets reviewers engage with the decision rather than reconstructing the problem.
Technology Evaluation Criteria	practice	Technology Selection	A standing set of dimensions for assessing a candidate technology, ensuring that operability and longevity are weighed alongside capability.
Technology Radar	practice	Enterprise Architecture	A published, periodically-reviewed view of which technologies are endorsed, tolerated, being trialled, or to be avoided.
Technology Stack Standardisation	practice	Technology Architecture	Converging on a supported set of platforms, languages and tools to reduce operational surface, while allowing justified exceptions.
Telemetry Cost Management	practice	Telemetry Cost	Controlling observability spend through sampling, retention tiering and cardinality limits without losing diagnostic capability.
Telemetry Sampling	practice	Observability	Keeping a subset of traces or events to bound observability cost, chosen so the ones that matter survive.
Telemetry Spend Ratio	metric	Observability Cost	Observability cost as a proportion of the infrastructure it observes, used as a tripwire for a category that grows silently.
Temporal Coupling	concept	Coupling	A dependency in which one component requires another to be available at the same moment, so the availability of both is required for either to work.
Terraform State IaC State File	concept	Infrastructure as Code	The file mapping declared resources to real infrastructure, without which the tool cannot tell what it already created — and which becomes critical infrastructure in its own right.
Test Pyramid	practice	Software Architecture	A distribution of tests weighted towards many fast unit tests, fewer integration tests, and very few slow end-to-end tests.
Testing Strategy Shape	concept	Testing Strategies	The distribution of tests across levels, chosen so that feedback is fast where it can be and confidence is real where it must be.
Theory of Constraints	concept	Constraint Thinking	The principle that a system's throughput is set by a single binding constraint, so improvement anywhere else produces nothing.
Thread Pool Isolation	pattern	Bulkheads & Isolation	Giving each downstream dependency its own pool of threads or permits, so one slow dependency cannot consume the capacity needed to serve everything else.
Threat Modelling	practice	Security Architecture	A structured exercise that identifies what can go wrong with a design, before it is built, by walking the system's trust boundaries.