Terminology

2185 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 areas2185 Architecture Fundamentals77 Distributed Systems107 Data Architecture110 Cloud Architecture89 Networking88 API & Integration Architecture82 Reliability & Resilience75 Observability70 Performance & Capacity Engineering72 Security Architecture81 Cost Architecture & FinOps66 Business Architecture67 Architecture Communication67 Enterprise Architecture66 Legacy Modernization66 AI-Era Architecture69 Software Architecture & Engineering71 Architecture Patterns71 Architecture Decision-Making63 The Architect's Meta-Skills61 Delivery & Release Engineering66 Platform Engineering & Developer Experience70 Testing & Quality Architecture66 Data Platform Architecture64 Streaming & Real-Time Data69 Data Governance & Semantics69 Frontend & Experience Architecture66 Edge, Mobile & IoT68 Regulatory & Data Protection Architecture65 Assurance, Audit & Model Risk64

Kind Any concept785 practice729 pattern362 metric125 case-study77 tool62 protocol45

63 terms shown.

Term	Kind	Topic	What it is
Access Pattern Driven Modelling	practice	SQL vs NoSQL	Designing the data model from the queries the application must serve, rather than from an abstract normalised representation of the entities.
ADR Lifecycle	practice	Decision Practice	The states an architecture decision record moves through — proposed, accepted, superseded, deprecated — and the discipline that keeps the set trustworthy.
Amazon Prime Video: Serverless Back to a Monolith Prime Video Audio/Video Monitoring	case-study	Monolith vs Microservices	A distributed serverless pipeline was consolidated into a single process, reducing cost by over 90% — for one component, for specific reasons that do not generalise.
Architecture Decision Record ADR	practice	Architecture Decision-Making	A short, immutable document capturing one architectural decision, its context, the alternatives, and its consequences.
Architecture Decision Record Practice	practice	Decision Practice	The habits that make decision records useful six months later — writing at decision time, recording rejected options, and never editing history.
Architecture Trade-off Analysis Method ATAM	practice	Architecture Decision-Making	A structured evaluation that scores an architecture against prioritised quality-attribute scenarios and identifies the points where those attributes conflict.
Build vs Buy	concept	Architecture Decision-Making	The choice between developing a capability in-house and acquiring it, decided on differentiation and total cost rather than on feature lists.
Build-vs-Buy Total Cost	practice	Build vs Buy	Comparing a purchased solution against building one on the full lifetime cost, including the maintenance and opportunity costs that estimates omit.
Centralisation Trade-off	concept	Centralised vs Distributed	The exchange between consistency and control gained by centralising a capability and the autonomy and speed retained by distributing it.
Centralised versus Distributed	concept	Centralised vs Distributed	Whether a capability should be one shared thing or many independent ones — a recurring decision whose answer changes with organisation size.
Complexity Budget	concept	Reliability vs Complexity	The idea that an organisation can operate only a bounded amount of complexity, so each resilience mechanism must justify its share.
Consistency Choices	practice	Strong vs Eventual Consistency	Deciding, per operation, the weakest consistency guarantee that is still correct — rather than choosing one model for a system.
Consistency Level Selection	practice	Strong vs Eventual Consistency	Choosing the consistency guarantee per operation rather than per system, matching the cost of coordination to the business consequence of staleness.
Correlated Region Failure Shared-Fate Region Dependency, Region Failure Correlation	concept	Single vs Multi-Region	The shared dependencies that make two regions fail together, which is why multiplying regions multiplies cost but adds far less availability than independence arithmetic predicts.
Cost Per Transaction	metric	Performance vs Cost	Infrastructure cost divided by business volume, which reveals efficiency trends that absolute spend conceals.
Decision Context Capture	practice	Architecture Decision Records	Recording the situation, constraints and forces that made a decision reasonable, so that later readers can judge whether it still applies.
Decision Debt Unrecorded Decision Backlog, Undocumented Choice Accumulation	concept	Decision Practice	The accumulated set of choices a system embodies but nobody wrote down, which turns every later change into an archaeology exercise and makes safe modification depend on individual memory.
Decision Granularity One Decision Per Record, Record Scope	practice	Architecture Decision Records	How much a single decision record covers, chosen so a later change can replace exactly the part that has become wrong instead of invalidating a document that is mostly still correct.
Decision Half-Life	metric	Architecture Decision Records	The observed time it takes for half a set of architecture decision records to be superseded, read as a diagnosis of how the records are written rather than of how unstable the system is.
Decision Rights Decision Ownership, Accountable Decider	practice	Architecture Decision-Making	An explicit statement of who decides what, so that consultation is bounded and decisions do not wait for a consensus nobody required.
Decision Trigger Revisit Condition, Pre-Agreed Threshold	practice	Managed vs Self-Managed	A number or condition agreed in advance that would cause a decision to be revisited - which converts a permanent choice into a monitored one and prevents both premature change and indefinite drift.
Decision Under Uncertainty	practice	Deciding Under Uncertainty	Choosing when the information needed to be confident is unavailable, using the cost of being wrong rather than waiting for certainty.
Deliberate Technical Debt	practice	Delivery vs Maintainability	A consciously chosen shortcut, recorded with its cost and a repayment trigger, as distinct from debt incurred by carelessness.
Delivery versus Maintainability	concept	Delivery vs Maintainability	Shipping faster now by accepting future cost — a legitimate trade when it is deliberate, recorded and repaid.
Differentiation Test	practice	Build vs Buy	The question of whether a capability is a source of competitive advantage, used as the primary filter in build-versus-buy decisions.
Execution Model Fit	concept	Serverless vs Containers	Matching a workload's traffic shape, duration and state requirements to the execution model that suits it, rather than choosing one model for everything.
Exit Cost Switching Cost, Cost of Exit	metric	Build vs Buy	The engineering effort and elapsed time required to move off a vendor, which sets both the real price of lock-in and the team's negotiating position at renewal.
Expensive-to-Change Core	concept	Delivery vs Maintainability	The small part of a system whose shape is copied into stored data and into other people's code, where a shortcut cannot be repaid locally - so deliberate debt belongs everywhere else.
Extraction Payback Period	metric	Monolith vs Microservices	The time it takes for the coordination cost a service extraction removes to repay the one-off extraction cost plus the permanent cost of running one more deployable - which is usually never unless the module h…
False-Decline Cost Cost of the False Positive, Friction Loss	metric	Security vs Usability	The value lost to legitimate customers rejected or deterred by a control - invisible in fraud metrics, frequently larger than the losses prevented, and the number that turns a values argument into arithmetic.
Friction Budget	concept	Security vs Usability	The limited amount of security friction users will absorb before they work around it, making usability a security property rather than its opponent.
Fully-Loaded Comparison Total Cost Comparison, People-Inclusive TCO, Loaded Build-vs-Buy	practice	Managed vs Self-Managed	Comparing options with engineering time, operational burden and opportunity cost included rather than infrastructure and licence prices alone - which usually reverses the apparent answer at small and medium scale.
Latency Revenue Elasticity	metric	Performance vs Cost	The measured change in a business outcome per unit of added or removed latency, which turns "faster is better" into an amount of money and tells you when to stop buying milliseconds.
Managed versus Self-Managed	practice	Managed vs Self-Managed	Whether to run a component yourself — a decision that should default to managed and require a specific articulated reason to deviate.
Monolith vs Microservices	concept	Architecture Decision-Making	A trade of deployment independence against distributed-systems complexity, decided by team topology far more often than by technology.
One-Way Door Irreversible Decision, Type 1 Decision, Foreclosed Option	concept	Reversibility	A decision whose reversal is prohibitively expensive or impossible, which is where analytical effort belongs - as distinct from the reversible majority, where deliberation typically costs more than being wrong.
One-Way Door Decision Type 1 Decision, Irreversible Decision	concept	Reversibility	A decision that is very costly or impossible to reverse, warranting deliberation proportionate to that permanence.
Operated Reliability Realised Availability	concept	Reliability vs Complexity	The availability a system actually achieves in the hands of the team running it - as distinct from the availability its topology implies.
Operational Burden Assessment	practice	Managed vs Self-Managed	Quantifying the ongoing engineering effort a self-managed component requires, so it can be compared honestly with a managed service's price.
Performance versus Cost	concept	Performance vs Cost	The trade between latency and spend — where headroom is the mechanism and high utilisation is the false economy.
Query Surface Volatility	concept	SQL vs NoSQL	How fast a product invents query shapes it did not have before - the workload fact that decides whether a purpose-built physical layout or a general query planner is the cheaper bet.
Recorded Assumption Named Assumption with Trigger, Invisible-to-Monitored	practice	Deciding Under Uncertainty	Writing down the assumption a decision rests on, with the condition that would invalidate it - which converts an invisible dependency into a monitored one.
Region Selection Criteria	practice	Single vs Multi-Region	The factors determining where workloads run, in which data residency and latency usually dominate cost.
Region Strategy	practice	Single vs Multi-Region	How many regions, where, and in what topology — driven by residency, latency and availability requirements rather than by ambition.
Reliability versus Complexity	concept	Reliability vs Complexity	Mechanisms added for reliability introduce their own failure modes — so past a point, more machinery makes a system less reliable.
Request-Reply and Fire-and-Forget	concept	Sync vs Async	The two interaction shapes available between components, differing in whether the caller waits for a result and therefore in whether availability compounds.
Reversible Decision Two-Way Door	concept	Architecture Decision-Making	A choice that can be undone cheaply, and which therefore deserves far less deliberation than an irreversible one.
Scenario-Based Comparison Concrete Scenario Evaluation, Cash Out the Qualities	practice	Trade-off Analysis Methods	Comparing design options against specific described situations rather than against abstract qualities - which forces vague terms to be cashed out and turns a discussion into a decision.
Security versus Usability	concept	Security vs Usability	Controls that impose too much friction get circumvented — so the usable control is frequently the more secure one.
Sensitivity Analysis What-Would-Change-The-Answer Analysis	practice	Trade-off Analysis Methods	Identifying which assumption, if wrong, would change the decision - which tells you what to measure early and what to design to change cheaply.
Spike and Prototype	practice	Deciding Under Uncertainty	A time-boxed experiment run to reduce uncertainty about a specific question, producing evidence rather than a component.
Spotify: Trading Kafka Operations for a Managed Service Spotify Event Delivery	case-study	Managed vs Self-Managed	Spotify moved its event delivery backbone from self-managed Kafka to a managed pub/sub service, choosing to buy back operational capacity rather than deepen expertise.
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.
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.
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.
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 Selection	practice	Technology Selection	Choosing a technology on the basis of fit, operability and organisational capacity — with a strong prior toward what you already run well.
Trade-off Analysis Methods	practice	Trade-off Analysis Methods	Structured ways to compare architectural options — valuable for making reasoning explicit, dangerous when they produce false precision.
Trigger Condition Revisit Trigger, Decision Tripwire, Monitorable Assumption	practice	Deciding Under Uncertainty	A specific, observable condition recorded alongside a decision that indicates it should be reconsidered - converting a point-in-time judgement into a monitorable position.
Two-Way Door	concept	Reversibility	A decision that can be undone cheaply, and which therefore warrants a fast decision by the people closest to the work rather than extensive analysis.