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

2185 terms shown.

Term	Kind	Topic	What it is
Artifact Signing	practice	Supply Chain Security	Cryptographically signing build outputs so that deployment can verify what is being run was produced by the expected pipeline from the expected source.
Aspirational and Achievable SLO	practice	SLI, SLO & SLA	The distinction between the reliability a team wishes for and the reliability its current architecture and dependencies can actually deliver.
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.
Assumption Excavation	practice	First-Principles Reasoning	Deliberately surfacing the unstated beliefs behind a design or a requirement, to test which are constraints and which are merely habits.
Assumption Register	practice	Technical Constraints	The record of the numeric assumptions a design was sized against, monitored so the architecture announces when its own premises expire.
Assurance and Governance	concept	Assurance, Audit & Model Risk	Providing confidence that controls exist and operate — through automation and evidence rather than through review meetings.
Assurance Map	practice	Assurance, Audit & Model Risk	A single view of which risks are covered by which assurance activity, exposing both the gaps nobody is looking at and the duplication several parties are paying for.
At-Least-Once Delivery Redelivery Semantics, Duplicate-Tolerant Delivery	concept	Webhooks	The delivery guarantee that a message will arrive but may arrive more than once - the strongest practical guarantee across an unreliable boundary, which pushes the deduplication responsibility onto the receiver.
Atomic Commit Protocol	concept	Distributed Transactions	Any protocol ensuring that several participants reach the same decision to commit or abort — and a problem provably unsolvable with certainty in an asynchronous system with failures.
Attack Surface	concept	Threat Modelling	The complete set of points where an untrusted actor can interact with a system — and the quantity that reduction genuinely reduces risk.
Attack-Path Framing Path-Based Finding, Attack-Path Finding Format	practice	Communicating Threat Models	Writing each security finding as a reachable path from entry point to impact with the one change that removes it and the cost of that change, replacing severity scores that can be argued with instead of acted on.
Attestation Freshness Nonce-Bound Quote, Replay-Resistant Attestation	concept	Edge Security & Attestation	The property that a hardware attestation can only be used in the exchange that requested it - without which a captured measurement is a reusable bearer token for the whole fleet.
Attestation Transparency Log Verifiable Transparency, Published Measurement Log	pattern	Edge Security & Attestation	A public append-only log of every software measurement a fleet is allowed to run, checked by the client before it sends data, which removes the possibility of a build served to one user only.
Attribute History Strategy	concept	Slowly Changing Dimensions	The per-attribute decision about whether history is overwritten, versioned or kept alongside the current value, which is a business question rather than a technical one.
Audit Evidence	concept	Audit Evidence	Durable, tamper-resistant records demonstrating that a control operated as described, for every instance in the period under review.
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.
Authorization Code Flow with PKCE PKCE	protocol	OAuth 2.0 & OIDC	The OAuth flow recommended for all client types, in which an authorisation code is exchanged for tokens using a proof key that binds the exchange to the original requester.
Automated Accessibility Coverage	metric	Accessibility Testing	The proportion of accessibility criteria a tool can decide mechanically — around a third — and the explicit acknowledgement that the rest needs people.
Automated Governance	practice	Fitness Functions	Encoding architectural rules as executable checks in the build pipeline, so conformance is verified continuously rather than reviewed periodically.
Automated Release Verification	practice	Deployment Gates	A gate that compares the new version's live signals against the old one's and decides, on stated criteria, whether to continue or revert.
Automation Bias Deference to Automation, Rubber-Stamp Oversight	concept	Human-in-the-Loop Design	The well-documented tendency for people to defer to a system's output rather than assess it independently - which is why nominal human oversight provides no protection.
Automation Ratchet Residual Difficulty, Hard-Case Concentration	concept	Human in the Loop	The effect where improving automation makes the cases reaching humans systematically harder, so reviewer throughput falls and error rates rise even as the overall system improves.
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 Arithmetic	concept	Availability Mathematics	Multiplying dependency availabilities in series and combining redundant components in parallel to derive a system's achievable availability.
Availability Calculation	concept	Reliability & Resilience	Deriving a system's availability from its components, remembering that dependencies in series multiply.
Availability Composition	concept	Availability Mathematics	How the availability of a system follows from its dependencies — multiplying for serial dependencies and improving sharply for redundant ones.
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.
Availability Zone Independence	concept	Availability Zones	The property that a failure in one zone does not propagate to another, and the design work needed to actually benefit from it.
AWS S3 2017: The Blast Radius of a Typo S3 us-east-1 Outage	case-study	Failure Modes	A mistyped command during routine debugging removed far more capacity than intended, and the affected subsystems had not been restarted in years.
AWS: Shuffle Sharding Shuffle Sharding, Virtual Sharding	case-study	Cell-Based Architecture	Assigning each customer a random subset of workers rather than a fixed shard, so that one abusive tenant affects almost nobody else.
AWS: Static Stability Across Availability Zones Static Stability	case-study	Static Stability	AWS designs services to keep working with the capacity they already have when a zone fails, rather than needing the control plane to provision replacements.
B2B Integration	practice	Partner & B2B Integration	Integrating with partner organisations, where the technical problem is small and the versioning, onboarding and support problems are large.
Backend for Frontend BFF	pattern	Backend for Frontend	A dedicated backend per client experience, owned by the team that owns that client, so each surface gets exactly the payload it needs.
Backend for Frontend BFF	pattern	BFF for Experience	A dedicated backend per client experience, owned by the client team, that shapes and aggregates downstream services for that client's exact needs.
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.
Backfill	practice	Batch Orchestration	Reprocessing historical periods through a pipeline after fixing a defect or adding a field, at a scale the pipeline was not sized for.
Background Work on Mobile	concept	Push & Background Work	Work scheduled outside the foreground session, which mobile operating systems aggressively restrict to protect battery life.
Backhaul Cost per Device-Day Bytes per Device-Day, Per-Device Data Budget	metric	Constrained Protocols	The bytes a single device sends and receives in a day multiplied by the price of the link - the figure that converts a sampling decision into a line in the connectivity contract.
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.
Backpressure in Practice Flow Control, Push-Back	pattern	Backpressure & Flow Control	Signalling upstream to slow down so queues stay bounded, and what to do at boundaries where the producer cannot be slowed.
Backpressure in Streaming	concept	Streaming & Real-Time Data	A slow downstream stage signalling upstream to slow down, so that queues stay bounded instead of consuming memory until the job dies.
Backstage-Style Service Catalogue Software Catalogue, Service Registry	tool	Internal Developer Platform	A queryable inventory of every service, its owner, its dependencies, its documentation and its operational state.
Backup Restore Testing	practice	Backup Strategies	Periodically performing a full restore and measuring it, on the basis that an untested backup is a hypothesis rather than a capability.
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.
Bake Time	concept	Multi-Region Rollout	The deliberate wait between rollout steps, sized by how long the fault you are watching for takes to appear.
Bandwidth-Delay Product	concept	Network Performance	Bandwidth multiplied by round-trip time — the amount of data that must be in flight to keep a link fully utilised.
Base Image Currency	metric	Container Image Strategy	How far behind the fleet's running images are from their patched base, which is the number that decides how fast a critical vulnerability can be closed.
Base Layer Rebase Run Image Swap, Image Rebasing	pattern	Container Image Strategy	Replacing the operating-system layers underneath an already-built container image without re-running the application build, so a base-image fix reaches hundreds of services in minutes rather than waiting on ev…
Batch Orchestration Workflow Orchestration, DAG Scheduling	concept	Batch Orchestration	Running interdependent data jobs in the right order with retries, backfills and failure handling, expressed as a dependency graph rather than a schedule.
Beacon Survivorship RUM Survivorship Bias, Abandonment Bias	concept	Real User Monitoring	The bias in field performance data caused by users abandoning a page before the measurement beacon is sent - so the slowest sessions are excluded and the metric improves as the experience gets worse.
Behavioural Specification Gap Structure-Only Reference, Diagram-Level Standard	concept	Reference Architectures	The omission in a reference architecture that specifies components and call directions but not behaviour under failure - so every team that complies invents the same timeout and retry defaults and produces the…
Benefit Realisation Checkpoint Post-Implementation Benefit Review, Benefit Sign-Off Gate	practice	Outcome Measurement	A scheduled review after go-live at which the budget holder confirms whether the claimed benefit has appeared in a named line, so that a benefit which never arrives is distinguishable from one that did.
Best Effort Delivery	concept	Push & Background Work	The guarantee push notification services actually offer — which is none — and the design consequences of building on a channel that may silently drop.
BGP Border Gateway Protocol	protocol	Routing & BGP	The protocol by which autonomous systems advertise which address ranges they can reach, determining how traffic finds any destination on the internet.
BI Governance	practice	BI Governance	Keeping business intelligence trustworthy — through certified definitions and a semantic layer, without preventing analysts from working.
Bias and Fairness Control	practice	Bias & Fairness Controls	Measuring and constraining disparate outcomes across groups, where the definition of fairness must be chosen deliberately because the definitions are mutually incompatible.
Bidirectional Contract	pattern	Contract Tests	A contract verified from both sides — the consumer's expectations and the provider's actual behaviour — without either running the other's tests directly.