Terminology

276 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 areas276 Architecture Fundamentals16 Distributed Systems24 Data Architecture23 Cloud Architecture16 Networking13 API & Integration Architecture15 Reliability & Resilience15 Observability13 Performance & Capacity Engineering12 Security Architecture18 Cost Architecture & FinOps11 Business Architecture9 Architecture Communication8 Enterprise Architecture8 Legacy Modernization8 AI-Era Architecture15 Software Architecture & Engineering18 Architecture Patterns15 Architecture Decision-Making11 The Architect's Meta-Skills8

Kind Any concept85 practice78 pattern51 case-study26 tool13 protocol12 metric11

276 terms shown.

Term	Kind	Topic	What it is
Abstraction	concept	Architecture Fundamentals	Exposing what a component does while hiding how it does it, so callers depend on the contract rather than the mechanism.
AI Gateway	pattern	AI-Era Architecture	A shared proxy in front of model providers that centralises routing, keys, quotas, caching, logging and safety policy.
Airbnb's Service-Oriented Migration	case-study	Legacy Modernization	Airbnb decomposed a large Rails monolith by first extracting a unified data-access layer, so that services were built on owned data rather than on shared database tables.
Alert Fatigue	concept	Observability	The desensitisation that follows from alerts that are frequent, non-actionable, or not tied to user impact — after which real alerts are missed too.
Anti-Corruption Layer ACL	pattern	Legacy Modernization	A translation layer that converts a legacy or external system's model into your own, so its concepts do not leak into your domain.
Anycast	concept	Networking	Advertising the same IP address from many locations, so the network routes each client to the topologically nearest one.
API Gateway	pattern	API & Integration	A single entry point in front of a set of services that handles authentication, rate limiting, routing and protocol translation.
Application Performance Monitoring APM	tool	Observability	Instrumentation inside the application that attributes latency and errors to specific code paths, queries and dependencies.
Application Portfolio Management APM, Application Rationalisation	practice	Enterprise Architecture	Maintaining an inventory of every application with its owner, cost, business value and technical health, and using it to decide what to invest in, replace or retire.
Architectural Driver	concept	Architecture Fundamentals	The small subset of requirements and constraints that actually shape the structure of the system.
Architecture Cost Model	practice	Cost & FinOps	A calculation, made during design, of what an architecture will cost to run at expected and at peak volume.
Architecture Decision Log ADR Log, Decision Register	practice	Architecture Communication	The ordered, immutable collection of a system's decision records, read as a history rather than as a specification.
Architecture Decision Record ADR	practice	Architecture Decision-Making	A short, immutable document capturing one architectural decision, its context, the alternatives, and its consequences.
Architecture Principle	practice	Architecture Fundamentals	A durable, agreed rule that constrains design decisions in advance, stated with its rationale and its implications.
Architecture Review Board ARB, Design Authority	practice	Enterprise Architecture	A forum that reviews significant designs against standards, risks and strategy before commitment.
Architecture Style	concept	Architecture Fundamentals	A named, coarse-grained way of organising a whole system, as distinct from a pattern that solves one recurring problem inside it.
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.
Auditability	concept	Security Architecture	The ability to reconstruct who did what, to which resource, when, and from where — reliably enough to be relied upon after the fact.
Authentication AuthN	concept	Security Architecture	Establishing who a principal is, to a defined level of confidence.
Authorization AuthZ	concept	Security Architecture	Deciding whether an authenticated principal may perform a specific action on a specific resource.
Autoscaling	pattern	Cloud Architecture	Adding and removing capacity automatically in response to a demand signal, to track load without paying for peak all the time.
Availability Calculation	concept	Reliability & Resilience	Deriving a system's availability from its components, remembering that dependencies in series multiply.
Availability Zone AZ	concept	Cloud Architecture	One or more physically separate data centres inside a cloud region, with independent power, cooling and network, connected by low-latency links.
Backend for Frontend BFF	pattern	Architecture Patterns	A separate, narrow backend per client experience, which aggregates and reshapes downstream services for exactly that client's needs.
Backpressure	concept	Distributed Systems	A mechanism by which a component under load tells its callers to slow down, rather than accepting work it cannot complete.
Backup Strategy 3-2-1 Rule	practice	Cloud Architecture	A plan for what is copied, how often, where to, how long it is kept, and — the part that decides whether it is real — how the restore is verified.
Backward Compatibility	concept	API & Integration	The property that a new version of a producer continues to work with clients written against the old version.
Blameless Postmortem	practice	Reliability & Resilience	An incident review that seeks the systemic conditions that made a failure possible, explicitly excluding individual fault.
Blast Radius	concept	Cloud Architecture	The set of things that break, or become reachable, when one component fails or is compromised.
Blast Radius Reduction	practice	Cloud Architecture	The set of deliberate partitions — accounts, regions, zones, cells, tenants, deployment stages — that bound how far any single failure or compromise can reach.
Bloom Filter	tool	Data Architecture	A compact probabilistic structure that answers "is this key definitely absent, or possibly present?" — no false negatives, tunable false positives.
Blue-Green Deployment	pattern	Software Architecture	Running two identical production environments and switching traffic from the old one to the new one in a single cut, with the old kept warm for rollback.
Booking.com's Experimentation Platform	case-study	Business Architecture	Booking.com runs over a thousand concurrent experiments and treats the ability to test any change safely as a platform capability rather than a product feature.
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.
Bulkhead	pattern	Distributed Systems	Partitioning resources so that exhaustion caused by one dependency or tenant cannot starve the others.
Business Capability	concept	Business Architecture	What a business does, expressed stably and independently of how it currently does it or who is responsible.
C4 Model	practice	Architecture Communication	A set of four nested diagram levels — context, container, component, code — that keeps each diagram at one consistent level of abstraction.
Cache Invalidation	concept	Data Architecture	The problem of removing or refreshing cached data when the underlying source changes, and the reason caching is harder than it looks.
Caching Strategy	pattern	Performance & Capacity	The chosen pattern for how a cache is populated, read and invalidated — cache-aside, read-through, write-through or write-behind.
Canary Release	pattern	Software Architecture	Routing a small fraction of traffic to a new version, watching its metrics, and expanding or rolling back based on what they show.
CAP Theorem Brewer's Theorem	concept	Distributed Systems	During a network partition a distributed system must choose between consistency and availability; it cannot have both.
Capability Map	practice	Enterprise Architecture	A structured view of everything a business does, used as the stable frame for mapping applications, investment, ownership and gaps.
Capacity Planning	practice	Reliability & Resilience	Deciding in advance how much capacity will be needed, given growth, seasonality and failure scenarios, and ensuring it can be there in time.
Capital One's Data Centre Exit	case-study	Enterprise Architecture	A major US bank closed all eight of its data centres and moved fully to public cloud, treating governance automation as the enabling technology rather than a constraint.
Cardinality	concept	Observability	The number of distinct time series produced by a metric, which is the product of the distinct values of all its labels — and the main driver of monitoring cost.
Cell-Based Architecture Cellular Architecture	pattern	Architecture Patterns	Partitioning a service into complete, independent copies of itself, each serving a subset of customers, so a failure is bounded to one cell.
Change Data Capture CDC	pattern	Data Architecture	Publishing a stream of a database's row-level changes by reading its replication log, without modifying the application that owns it.
Chaos Engineering	practice	Reliability & Resilience	Deliberately injecting failure into a system to discover, before an incident does, which of your resilience assumptions are false.
Chargeback and Showback	practice	Cost & FinOps	Attributing cloud cost to the teams that generate it — either informationally (showback) or by moving it onto their budget (chargeback).
CI/CD Continuous Integration, Continuous Delivery	practice	Software Architecture	Merging work continuously into a shared trunk with automated verification, and keeping every commit in a state that could be released.
Circuit Breaker	pattern	Distributed Systems	A proxy that stops calling a failing dependency after a failure threshold, failing fast instead, and periodically tests whether it has recovered.
Clean Architecture	pattern	Software Architecture	Concentric layers with a strict dependency rule — source code dependencies point only inwards, towards higher-level policy.
Cloud Pricing Models	concept	Cost & FinOps	The purchase options for cloud compute — on-demand, committed use, and spot — which differ by up to 90% for identical hardware.
Cognitive Load	concept	Software Architecture	The total amount a team must hold in its head to work effectively, and a real constraint on how many services or domains one team can own.
Cohesion	concept	Architecture Fundamentals	The degree to which everything inside one component belongs together and changes for the same reason.
Competing Consumers	pattern	Architecture Patterns	Multiple identical consumers reading from one queue, so throughput scales with consumer count and work is distributed automatically.
Compliance Framework SOC 2, ISO 27001, PCI DSS	practice	Security Architecture	A published set of control requirements an organisation is assessed against, which turns security posture into evidence somebody else will check.
Concurrency	concept	Performance & Capacity	The number of operations in progress at once — distinct from parallelism, which is how many are literally executing simultaneously.
Connection Pool	concept	Performance & Capacity	A fixed set of reusable database connections shared by an application's requests, and one of the most common hidden capacity ceilings.
Consistent Hashing	concept	Distributed Systems	A hashing scheme where adding or removing a node remaps only a small fraction of keys, instead of nearly all of them.