Terminology

384 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 areas384 Architecture Fundamentals16 Distributed Systems73 Data Architecture71 Cloud Architecture17 Networking13 API & Integration Architecture17 Reliability & Resilience16 Observability14 Performance & Capacity Engineering13 Security Architecture18 Cost Architecture & FinOps12 Business Architecture9 Architecture Communication8 Enterprise Architecture8 Legacy Modernization11 AI-Era Architecture15 Software Architecture & Engineering19 Architecture Patterns15 Architecture Decision-Making11 The Architect's Meta-Skills8

Kind Any concept136 practice90 pattern81 case-study26 protocol19 tool19 metric13

90 terms shown.

Term	Kind	Topic	What it is
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.
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 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.
Backfill	practice	ETL & ELT	Re-running a pipeline over historical periods to populate new data or correct a past error, and the operation that proves whether a pipeline is well designed.
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.
Blameless Postmortem	practice	Reliability & Resilience	An incident review that seeks the systemic conditions that made a failure possible, explicitly excluding individual fault.
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.
Burn Rate Alerting	practice	SLO Monitoring	Paging when the error budget is being consumed fast enough to matter, rather than when a component crosses a threshold.
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.
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.
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.
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.
Constraint Thinking	practice	Meta-Skills	Designing for the budget, timeline, skills, regulations and existing estate that actually exist, rather than for the ones a textbook assumes.
Contract Testing	practice	API & Integration	Verifying that a provider satisfies the expectations each of its consumers actually relies on, without running all the services together.
Correlation ID	practice	Observability	A single identifier attached to one logical operation and included in every log line it produces, anywhere in the system.
Data Contract	practice	Data Governance	An explicit, versioned, enforced agreement between a data producer and its consumers about schema, semantics, quality and change policy.
Data Lineage	practice	Data Governance	A record of where each dataset came from, what transformed it, and what depends on it — traced at table and ideally column level.
Data Retention Policy	practice	Data Architecture	A defined rule for how long each class of data is kept, where, and what happens at the end of it.
Data-Flow Diagram DFD	practice	Architecture Communication	A diagram of how data moves between processes, stores and external entities, with trust boundaries drawn on it.
Decision-Making Under Uncertainty	practice	Meta-Skills	Choosing well when the information is incomplete — by bounding the downside and buying information, rather than by waiting for certainty.
Denormalisation	practice	Data Architecture	Deliberately duplicating data across records to make reads cheap, accepting the write-time cost of keeping copies in step.
Disaster Recovery DR	practice	Reliability & Resilience	The plan and capability for restoring service after an event that takes out a whole site, region or system.
Domain-Driven Design DDD	practice	Software Architecture	Modelling software around the business domain, with boundaries drawn where the language of the business changes.
Egress Path Analysis	practice	Network & Egress Costs	Tracing where data physically moves in an architecture, because transfer charges follow paths that appear nowhere on the diagram.
Encryption at Rest and in Transit	practice	Security Architecture	Protecting stored data from disclosure if the medium is obtained, and network data from disclosure if the path is observed — two different controls against two different threats.
Enterprise Integration Patterns EIP	practice	API & Integration	A catalogue of named, composable messaging patterns — router, translator, aggregator, splitter, filter, dead letter channel — that gives integration work a shared vocabulary.
Error Budget Policy	practice	Error Budgets	The written agreement about what happens when the error budget is exhausted, which is what turns an SLO from a number into a control.
Evolutionary Architecture	practice	Architecture Fundamentals	Designing for guided, incremental change rather than trying to get the structure right once, up front.
Failure Thinking	practice	Meta-Skills	Making "what happens when this fails?" a standing question applied to every component and every dependency in a design.
FinOps	practice	Cost & FinOps	The practice of giving engineering teams visibility into and accountability for the cost of what they build and run.
First-Principles Reasoning	practice	Meta-Skills	Reducing a problem to the physical, mathematical or economic facts it rests on, then reasoning up, rather than reasoning from analogy or convention.
Fitness Function	practice	Architecture Fundamentals	An automated check that an architectural characteristic still holds, run continuously rather than reviewed occasionally.
Game Day	practice	Reliability & Resilience	A scheduled exercise in which a failure is deliberately introduced and the team responds as though it were real, to test the system and the response together.
Graceful Degradation	practice	Distributed Systems	Continuing to deliver reduced but useful function when a dependency fails, instead of failing the whole request.
Health Check	practice	Observability	An endpoint the platform polls to decide whether an instance should be restarted or should receive traffic — two different questions needing two different checks.
Idempotent Pipeline	practice	ETL & ELT	A pipeline whose task can be re-run for the same input window any number of times and produce the same result.
Incident Command Incident Command System, ICS	practice	Reliability & Resilience	Assigning explicit roles during an incident — commander, operations lead, communications lead, scribe — so coordination does not compete with diagnosis.
Indexing Strategy	practice	Data Architecture	Choosing the set of indexes a table carries by working backwards from its actual queries, and accepting the write cost that each one adds.
Infrastructure as Code IaC	practice	Cloud Architecture	Defining infrastructure in version-controlled declarative files that a tool reconciles against the real environment.
Landing Zone	practice	Cloud Architecture	A pre-configured, governed cloud environment — accounts, networking, identity, logging, guardrails — into which workloads can be deployed safely.
Little's Law Applied to Pools	practice	Connection Pooling	Using L = λW to size connection and thread pools from measured throughput and latency rather than from a default.
LLM Evaluation Evals	practice	AI-Era Architecture	A repeatable measurement of whether an AI system's outputs are good enough, on cases that reflect the actual task.
Load Testing	practice	Performance & Capacity	Driving a system with realistic traffic at a target volume to verify it meets its performance targets before real users do.
Negotiation	practice	Architecture Communication	Reaching an agreement that both sides own, by trading on interests rather than arguing positions.
Normalisation Normal Forms	practice	Relational Modelling	Organising a schema so each fact is stored exactly once, removing the update anomalies that duplication creates.
OWASP Top Ten	practice	Security Architecture	A periodically updated consensus list of the most critical web application security risks, useful as a design-review checklist.
Parallel Run	practice	Legacy Modernization	Running the old and new systems side by side on the same inputs and comparing outputs, before the new one is trusted.
Pattern Recognition	practice	Meta-Skills	Recognising that a novel-looking problem is an instance of one you have seen before, and knowing which parts of the previous solution transfer.
Paved Road Golden Path	practice	Enterprise Architecture	A supported, opinionated default way to build and run a service, made easy enough that teams choose it rather than being required to.
Pipeline Orchestration	practice	ETL & ELT	Coordinating the execution of data tasks by dependency rather than by clock, with retries, backfill and observability built in.
Pragmatism	practice	Meta-Skills	Preferring the simplest architecture that satisfies the requirements, and treating additional structure as a cost that must be justified.
Presenting to Engineers	practice	Architecture Communication	Presenting a design at the level of mechanism, including the alternatives rejected and the parts you are still unsure about.
Presenting to Executives	practice	Architecture Communication	Leading with the decision and the business consequence, at a level of abstraction where technology names do not appear.