Terminology

2205 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 areas2205 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 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 concept794 practice734 pattern368 metric125 case-study77 tool62 protocol45

2205 terms shown.

Term	Kind	Topic	What it is
Seam Identification	practice	Strangler Fig	Locating the places in a legacy system where behaviour can be intercepted and redirected, which determines whether an incremental migration is feasible at all.
Seasonality-Aware Threshold Same-Weekday Baseline, Seasonal Band	practice	Data Quality Dimensions	Setting a data quality alarm against the comparable period rather than the previous one, so that a business's own weekly and monthly rhythm does not generate alerts nobody can act on.
Second-System Effect	concept	Trade-off Fundamentals	The tendency for a replacement system to accumulate every capability the first one lacked, producing something more complex than either the old system or the problem requires.
Secret Zero Bootstrapping Problem	concept	Secrets Management	The credential a workload needs in order to authenticate to the secret manager — the one secret that cannot itself be stored in the secret manager.
Secret Zero Problem	concept	Secrets Management	The credential a workload needs in order to authenticate to the secret manager, which cannot itself be stored in the secret manager.
Secrets Management	practice	Security Architecture	Storing, distributing, rotating and auditing credentials so that they never live in code, images or configuration files.
Sector Cloud Rules	concept	Sector Cloud Rules	Sector-specific rules governing cloud use — outsourcing notification, audit rights, concentration risk and exit — which shape provider and service choices.
Secure Aggregation Private Aggregation, Cohort-Level Aggregation	protocol	Privacy-Enhancing Technologies	A cryptographic protocol that lets a server learn only the sum of many clients' model updates and never any single client's update, which is what makes an on-device training claim survive scrutiny.
Secure API Design	practice	Secure API Design	Building an interface where the safe path is the default and the unsafe one requires deliberate effort.
Secure Boot Chain	protocol	Edge Security & Attestation	Each boot stage verifying the signature of the next before executing it, anchored in immutable hardware, so only authorised software runs.
Security Design Review	practice	Security Design Review	A structured examination of an architecture's security properties before it is built, focused on trust boundaries and threat paths rather than on a checklist.
Security Group Firewall Rules, NSG	tool	Networking	A stateful, instance-level firewall that allows specified traffic and denies everything else by default.
Security Group Sprawl	concept	Network Security	The accumulation of firewall and security group rules that nobody can safely remove, producing a permissive posture nobody chose.
Security Incident Response	practice	Security Incident Response	Responding to a compromise — where the architecture determines whether you can detect it, contain it, and prove what happened.
Security Testing in the Pipeline Shift-Left Security, SAST/DAST/SCA	practice	Security Testing in the Pipeline	Automated security analysis embedded in the build, chosen and tuned so that findings are actionable rather than overwhelming.
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.
Segment-Isolated Serving Outlier Tenant Path, Heavy-User Isolation	pattern	Tail Latency	Giving a consistently slow population its own path - pool, precomputed view, or query strategy - rather than optimising the shared path to accommodate it.
Segregation of Duties SoD, Separation of Duties	concept	Segregation of Duties	Ensuring no single individual can both initiate and approve a sensitive action, so that fraud or error requires collusion.
Selective Reliability Partial Reliability, Deadline-Aware Delivery	concept	Pipes and Filters	Retransmitting only what is still useful and discarding what has expired - because for time-sensitive data, late delivery consumes capacity without providing value.
Selector Dependency Label Contract, Implicit Platform Dependency	concept	Cluster Architecture	A production dependency that exists only as a string matching a label or annotation, so it is invisible to code search and to release notes, and a platform upgrade that renames the label silently removes it.
Self-Service Provisioning	practice	Self-Service Provisioning	A developer obtaining infrastructure through an automated interface bound by policy, with no ticket and no human approval in the path.
Self-Service versus Governed	concept	Self-Service vs Governed	Balancing analyst autonomy against consistency — resolved by tiers and enforced definitions rather than by restricting access.
Semantic Cache	pattern	AI-Era Architecture	Caching model responses keyed by the meaning of the request rather than by its exact text, so near-duplicate questions are served without a model call.
Semantic Chunking	practice	Chunking & Retrieval	Splitting documents along their meaning and structure rather than at fixed character counts, because retrieval quality is bounded by chunk quality.
Semantic Coupling Meaning Drift, Invisible Event Coupling	concept	Publish/Subscribe	Dependence on what an event or field means rather than on its shape - the coupling that survives every schema check, breaks nothing when violated, and is the hardest failure to detect in an event-driven system.
Semantic Diffing of API Schemas	practice	Backward Compatibility	Comparing the published contract between builds and failing the build on a breaking change, so compatibility is mechanical rather than remembered.
Semantic Layer Metrics Layer, Headless BI	pattern	Semantic Layer	A single governed definition of business metrics and entities, sitting between physical tables and every consuming tool.
Semantic Schema Break Wire-Compatible Meaning Change	concept	Streaming Schema Evolution	A change that keeps a field's wire format valid while changing what its values mean, so every compatibility check passes and every consumer computes a wrong answer without raising an error.
Semantic Versioning SemVer	practice	API Versioning	A version scheme where the number itself states the compatibility promise — major for breaking, minor for additive, patch for fixes.
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.
Sensitivity Labelling Data Classification Tagging	practice	Sensitivity Labelling	Attaching a machine-readable classification to data at the column or asset level, so that downstream controls can be applied automatically.
Sensitivity Propagation	concept	Sensitivity Labelling	The rule that a derived dataset inherits the highest sensitivity of its inputs unless a named transformation demonstrably lowers it.
Sensor Input Validation Telemetry Plausibility Checking, Physical Input Sanitisation	practice	Physical-World Failure Modes	Treating readings from physical devices as untrusted input requiring plausibility checks - because a sensor that fails toward a well-formed wrong value is far more damaging than one that stops reporting.
Separation of Concerns	concept	Separation of Concerns	Organising a system so that one kind of change touches one place, and so that different concerns can fail and scale independently.
Separation of Concerns	concept	Architecture Fundamentals	Organising a system so each part addresses one concern, and a change to that concern touches one part.
Sequence Diagram	practice	Architecture Communication	A diagram showing the ordered exchange of messages between participants over time, used to make an interaction's control flow and failure points explicit.
Sequence Diagrams	practice	Sequence Diagrams	Showing the order of interactions over time — the only common diagram that makes latency, ordering and failure behaviour visible.
Server Name Indication SNI, TLS Host Extension	protocol	TLS & Certificates	The cleartext hostname a client sends in its first TLS message, letting one address serve many certificates and letting a proxy route a session before it decrypts anything.
Server State Versus UI State	concept	Client State Architecture	The distinction between data owned elsewhere and cached locally, and state that exists only in this session — conflating them causes most client state bugs.
Server-Driven UI Backend-Driven UI, Remote Screen Definition	pattern	Mobile Release Strategy	Describing screens as data returned by the server and rendered by native components - removing the app-store release from the change loop, in exchange for a permanent compatibility contract with every version …
Server-Sent Events SSE, EventSource	protocol	WebSockets & Realtime	A one-way streaming protocol over plain HTTP in which the server pushes text events to the client on a long-lived response.
Server-Side Request Forgery SSRF	concept	OWASP Risks	Inducing a server to make an HTTP request to an attacker-chosen destination, turning it into a proxy into networks and services the attacker cannot reach directly.
Serverless	concept	Cloud Architecture	A model where the provider allocates and scales compute per request, and you are billed for execution rather than for provisioned capacity.
Serverless Cold Start	concept	Serverless	The additional latency when a function invocation must allocate and initialise a new execution environment rather than reusing a warm one.
Serverless Compute in Practice Functions as a Service, FaaS	concept	Serverless	Compute billed per invocation with no capacity to manage — excellent for bursty low-duty-cycle work, expensive and constrained for sustained load.
Service Boundary	concept	Software Architecture	The line separating what one service owns and is accountable for from what it must ask another service about.
Service Boundary Heuristics	practice	Service Boundaries	The signals that indicate where a service boundary belongs, and the ones that reliably mislead.
Service Catalogue Entry	concept	Internal Developer Platform	The record that makes a service a first-class object in the platform — owner, dependencies, docs, runbooks and health in one place with a single identity.
Service Control Policy SCP, Azure Policy, Organization Policy	tool	Landing Zones	An organisation-level guardrail that limits what any identity in an account may do, regardless of the permissions granted within that account.
Service Discovery	pattern	Service Discovery	How a caller finds a healthy instance of a callee in an environment where instances appear and disappear continuously.
Service Discovery	concept	Distributed Systems	The mechanism by which a caller finds a currently healthy network address for a service whose instances are ephemeral.
Service Level Agreement SLA	concept	Reliability & Resilience	A contractual commitment about service level, with a defined remedy — usually a service credit — when it is missed.
Service Level Indicator SLI	metric	Reliability & Resilience	The actual measurement of a service's behaviour that an objective is set against — a ratio of good events to valid events.
Service Level Objective SLO	metric	Reliability & Resilience	An internal target for a service level indicator, set below the level at which users notice, and used to decide whether to ship or to stabilise.
Service Maturity Scorecard Production Readiness Scorecard	practice	Platform Adoption	An automated per-service assessment against the organisation's operational standards, visible to the owning team.
Service Mesh	tool	Service Mesh	Moving connection-level concerns — discovery, retries, timeouts, mTLS, telemetry — out of application code and into a proxy alongside every service.
Service Mesh	tool	Architecture Patterns	An infrastructure layer of sidecar proxies that handles service-to-service networking — mTLS, retries, timeouts, routing, telemetry — outside the application.
Service Mesh Networking	concept	Service Mesh Networking	What a mesh actually does at the network level, the cost per hop, and the shift from sidecar to shared-proxy models.
Service Mesh Operational Cost	concept	Service Mesh Operations	The ongoing engineering burden a mesh imposes — upgrades, proxy debugging, latency overhead and control-plane availability — weighed against the capabilities it provides.
Service Quota Service Limit	concept	Cloud Governance	A per-account, per-region cap on how much of a resource may be used — a common and easily-avoided cause of scaling failures and DR failures.