Terminology

2225 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 areas2225 Architecture Fundamentals77 Distributed Systems107 Data Architecture110 Cloud Architecture94 Networking88 API & Integration Architecture82 Reliability & Resilience75 Observability70 Performance & Capacity Engineering72 Security Architecture86 Cost Architecture & FinOps71 Business Architecture67 Architecture Communication67 Enterprise Architecture66 Legacy Modernization71 AI-Era Architecture74 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 Architecture69 Streaming & Real-Time Data69 Data Governance & Semantics74 Frontend & Experience Architecture66 Edge, Mobile & IoT68 Regulatory & Data Protection Architecture65 Assurance, Audit & Model Risk69

Kind Any concept801 practice736 pattern377 metric127 case-study77 tool62 protocol45

26 terms shown.

Term	Kind	Topic	What it is
Arrival Rate Model	concept	Performance Test Design	Driving a load test by requests arriving per second regardless of how the system responds, rather than by a fixed number of virtual users.
Assertion Strength What Coverage Does Not Measure, Mutation Score	concept	Mutation Testing	Whether a test would actually fail if the code were wrong - which coverage does not measure and mutation testing does, and which explains defects in fully-covered code.
Composition Accessibility Defect Assembled-Page Accessibility Defect, Integration-Level A11y Failure	concept	Accessibility Testing	An accessibility failure that exists only in the assembled page - focus order, landmark duplication, heading structure, announcement rate - and that every individually conformant component can pass its own che…
Configuration Corpus Parity Input Corpus Parity, Config Space Coverage	concept	Environment Parity	How closely the set of configurations a pre-production environment exercises resembles the set production actually carries - the parity dimension that decides whether a config-triggered latent bug is found by …
Consumer Contract	concept	Consumer-Driven Contracts	A machine-readable record of exactly which parts of a provider's response one consumer relies on, generated from that consumer's own tests.
Content-Channel Release Path Data Channel Deployment, Ungated Update Path	concept	Quality Gates	Any route by which an artefact reaches a running system without passing the gates that code passes - remote config, feature flags, rules tables, models, CDN rules, detection content - and which therefore carri…
Diagnostic Radius Failure Blast Radius, Signal Narrowness	concept	Test Pyramid Shapes	The number of distinct causes consistent with a test's failure - the property that actually separates the layers of a test suite and decides what a red build costs to investigate.
Emergent Failure Scale-Dependent Failure, Threshold Failure, Non-Linear Breakage	concept	Performance Test Design	A failure that exists only above a particular absolute scale because it depends on a fixed threshold rather than a ratio - which is why scaled-down environments validate code and not capacity.
End-to-End Test Cost Curve	concept	End-to-End Test Economics	How the cost of a broad end-to-end suite grows with its size while its marginal value falls, and where the two cross.
End-to-End Test Economics	concept	End-to-End Test Economics	The compounding maths that makes large end-to-end suites unaffordable and untrustworthy at scale.
Environment Parity	concept	Environment Parity	How closely a pre-production environment reproduces the properties of production that actually cause failures.
Fake Drift Virtualisation Divergence, Stale Mock	concept	Service Virtualisation	The divergence between a simulated dependency and the real one it stands in for - which makes tests pass while the real integration fails, producing confidence rather than caution.
Flake Rate Test Nondeterminism, Suite Trust Threshold, Intermittent Failure Rate	concept	Flaky Test Management	The proportion of test failures that are not caused by a real defect - a quantity with a sharp threshold, above which the suite stops being a signal and starts training the team to ignore failures.
Flaky Test	concept	Flaky Test Management	A test that passes and fails on unchanged code, destroying the signal value of the entire suite it belongs to.
Integration Test Boundary	concept	Integration Test Boundaries	The deliberate choice of what a test includes and what it stubs, which determines both what the test can detect and what it costs.
Production Parity Gap	concept	Environment Parity	The enumerated list of ways a pre-production environment differs from production, which is the list of defect classes it cannot catch.
Provenance Parity History Parity, Build-Path Parity	concept	Environment Parity	Similarity between environments in how they were built and changed over time - the parity dimension that decides whether a rehearsal transfers, and the one that manifests and version numbers cannot show.
Service Stub Fidelity	concept	Service Virtualisation	How faithfully a stand-in dependency reproduces the real one's behaviour — including its errors, latency and limits — which bounds what testing against it proves.
Steady-State Hypothesis	concept	Chaos as a Test	The measurable statement of normal behaviour that a chaos experiment predicts will hold while a fault is injected, without which the exercise is not a test.
Synthetic Data Fidelity	concept	Synthetic Data	How closely generated data reproduces the shape, distribution and awkwardness of the real thing, which decides what the data can validly be used for.
Test Double Boundary	concept	Integration Test Boundaries	The line inside a test between what is real and what is substituted, which determines exactly what the test can and cannot prove.
Test Strategy Altitude	concept	Testing & Quality Architecture	Deciding which risks are verified at which level, so that each layer tests something the layers below it structurally cannot.
Testability Design for Test	concept	Testing & Quality Architecture	The architectural property that determines what kinds of test are possible - which decides the shape of the suite far more than any testing discipline does.
Testability as a Design Property	concept	Test Architecture Strategy	How cheaply a system's behaviour can be observed and controlled, which is decided by architecture and largely fixed before any test is written.
Testing Trophy	concept	Test Pyramid Shapes	A distribution weighted towards integration tests rather than unit tests, appropriate where most of the risk lives at boundaries rather than in logic.
Traffic-Mix Skew Canary Population Bias, Assignment Bias	concept	Testing in Production	A canary or experiment arm receiving a population that differs systematically from the baseline - so the comparison measures who was routed rather than what changed.