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

794 terms shown.

Term	Kind	Topic	What it is
Good Enough Architecture	concept	Pragmatism	Designing to what the situation actually requires rather than to what would be ideal, on the basis that unnecessary sophistication carries permanent cost.
Governance Operating Model	concept	Architecture Governance	The arrangement of decision rights, review points and automated controls through which architectural intent is maintained across an organisation.
Governed Path Bypass Shadow Access Route, Route-Around	concept	Self-Service vs Governed	Any route to data that reaches it without passing the controls the organisation believes are in force, which is what makes a correct policy optional rather than binding.
Governed Self-Service	concept	Self-Service vs Governed	Letting anyone analyse anything while constraining what may be treated as authoritative, which resolves the apparent conflict between speed and consistency.
GraphQL N+1 Problem DataLoader Pattern	concept	GraphQL	The query explosion that occurs when each item in a list independently resolves its nested fields, turning one request into hundreds of database calls.
Gray Failure Partial Failure, Fail-Slow	concept	Failure Modes	A component that is degraded rather than down, passing health checks while serving a portion of requests slowly or incorrectly.
Greenfield Velocity Illusion Rewrite Head Start, Front-Loaded Rewrite Progress	concept	Rebuild vs Re-architect	The early speed advantage a from-scratch rebuild shows because it is running with all the real constraints switched off, which makes its estimate systematically wrong in the same direction every time.
Grey Failure Partial Failure, Fail-Slow	concept	Failure Modes	A component that is degraded rather than down — slow, intermittently erroring, or failing for a subset of operations — which defeats health checks built for binary states.
gRPC Status Codes	concept	gRPC APIs	A fixed set of codes that classify failures and tell a client whether retrying is appropriate.
gRPC Streaming	concept	gRPC Transport	Four call patterns — unary, server streaming, client streaming and bidirectional — built on HTTP/2 streams.
Guarantee Surface Promise Surface, Service Guarantee Footprint	concept	Product Thinking	The set of customer-facing promises a product has made, each of which obliges the architecture to detect its own breach and pay for it - so this surface, not the feature count, drives a whole class of build cost.
Half-Open State	concept	Circuit Breakers	The circuit breaker state that allows a limited number of trial requests through to test whether a failed dependency has recovered.
Hardware Backed Credential	concept	Device Identity	A private key generated inside a secure element and unable to leave it, so device identity cannot be copied off the device.
Harvest and Yield	concept	CAP & PACELC	A refinement of CAP that treats availability as a continuum — yield is the fraction of requests answered, harvest is the fraction of data reflected in an answer.
Head-of-Line Blocking	concept	HTTP/1.1, HTTP/2 & HTTP/3	One delayed item stalling everything queued behind it, even when the rest could have been processed - the failure mode that ordering guarantees create.
Health Check Configuration	concept	Layer 4 vs Layer 7	The interval, timeout, and healthy/unhealthy thresholds that together determine how quickly a failed backend leaves rotation.
Health Check Depth Shallow vs Deep Health Check, Dependency Health Check	concept	Failover	How much of a service's dependency graph a health check consults, which determines whether the check reports an independent fault or a shared one that every instance will report at the same moment.
Healthcare Data Protection	concept	Healthcare Data Protection	Architecture for health information — where access must be broad enough for care, auditable in detail, and safe when the system is unavailable.
Hidden Cost Categories	concept	Total Cost of Ownership	The recurring costs routinely omitted from total-cost-of-ownership comparisons, which usually exceed the licence or infrastructure line everyone argues about.
Horizontal vs Vertical Scaling Scale Out vs Scale Up	concept	Performance & Capacity	Adding more machines versus making one machine bigger — and the fact that vertical is underrated for stateful tiers.
Hot Key Hot Partition, Hot Row, Key Skew, Celebrity Problem	concept	Partitioning & Sharding	A single key or narrow key range receiving a disproportionate share of traffic, so one partition saturates while the rest of the cluster is idle - the failure that no amount of horizontal scaling fixes.
Hot Key Hot Partition, Hot Shard	concept	Partitioning & Sharding	A single key or partition receiving a disproportionate share of traffic, so that a well-balanced key space still produces one overloaded node.
Hot Partition Hot Shard, Hot Key	concept	Partitioning & Sharding	One partition receiving disproportionate traffic, so the system saturates at a fraction of its aggregate capacity.
Hot, Warm and Cold Data	concept	Data Lifecycle & Retention	Classifying data by how frequently and how urgently it is accessed, so each tier can be stored on media priced for that access pattern.
HTTP Method Semantics	concept	REST Design	The safety, idempotency and cacheability guarantees each HTTP method carries, which clients and intermediaries rely on.
Hydration	concept	Hydration Cost	The browser attaching interactivity to server-rendered HTML by re-running component logic, during which the page looks ready and is not.
Idempotency	concept	Distributed Systems	The property that performing an operation many times has the same effect as performing it once.
Idempotency Scope	concept	Idempotency Keys	The boundary within which an idempotency key is unique and meaningful — per account, per endpoint, or global — and the retention window it lives for.
Identifier Reuse Hazard Code Recycling, Key Reassignment	concept	Reference Data	The silent corruption that occurs when a retired code or key is later assigned to a different real-world entity, so historical facts join to the wrong meaning with no error anywhere.
Identity and Access Management IAM	concept	Security Architecture	The system of record for principals, credentials and permissions, and the policy engine that decides what each principal may do.
Idle Connection Race Keep-Alive Race, Idle Pool Reset	concept	HTTP/1.1, HTTP/2 & HTTP/3	The unavoidable window where a server closes a pooled connection just as a client sends a request on it, producing a small error floor that is worst when traffic is lightest.
Idle Cost	concept	Cost per Request	The portion of infrastructure spend incurred regardless of traffic, which determines how cost per request behaves as volume changes.
Idle Source Stall Watermark Stall, Silent Pipeline Halt, Quiet Partition Problem	concept	Streaming SLOs	A stream processor whose event-time progress halts because one partition or source has stopped producing - so output ceases entirely while every component reports healthy.
Image Pull Amplification Per-Node Image Cost, Cold Node Pull Cost	concept	Container Image Strategy	The property that a container image's size is paid on every node that has never seen that version, so its real cost scales with node churn and scale-out events rather than with release frequency.
Immutable Store Erasure Conflict	concept	Erasure vs Immutability	The direct contradiction between architectures designed never to forget and obligations requiring data to be removed, which must be resolved in the design rather than in policy.
In-Country Processing	concept	Data Residency	Keeping data within a jurisdiction across every path it takes — including backups, logs, telemetry, support access and the disaster recovery region.
Independent Assurance	concept	Three Lines Model	Assessment by a function with no involvement in designing or operating the control, which is what makes the assessment worth anything.
Independent Deployability	concept	Microservices	The property that a service can be released to production without coordinated release of any other, which is the defining benefit of microservices.
Index Write Amplification Index Maintenance Cost, Secondary Index Overhead	concept	Database Performance	The multiplication of write work caused by secondary indexes, where every insert and every update to an indexed column must also maintain each index tree inside the same transaction.
Indexing	concept	Indexing	Auxiliary structures that turn a scan into a lookup — the highest-leverage database intervention and the one most often applied blindly.
Indirect Prompt Injection	concept	Prompt Injection Defence	An attack in which malicious instructions are placed in content the model will later retrieve, rather than typed by the user.
Inference Request Path	concept	LLM Application Architecture	The sequence of stages an LLM application request passes through, each with distinct latency, cost and failure characteristics.
Information Hiding	concept	Modularity	Designing module boundaries around the decisions most likely to change, so that a change is contained within one module.
Ingest Fan-In	concept	IoT Ingest Architecture	The shape of a system receiving many small messages from very many senders, where connection count rather than data volume is the primary constraint.
Ingestion Pattern	concept	Ingestion Patterns	The mechanism by which data leaves a source system, which determines freshness, source load and how faithfully change is captured.
Inner Loop	concept	Inner Loop & Outer Loop	The edit-build-test cycle a developer repeats dozens of times an hour, entirely on their own machine or environment.
Inner-Loop Multiplier Frequency Times Duration, Daily Friction Cost	concept	Inner Loop & Outer Loop	The reason inner-loop friction dominates developer productivity - the loop runs dozens of times a day, so a small duration difference multiplies into hours, while the outer loop runs a few times.
Insider Risk by Design	concept	Auditability	Designing so that a legitimate operator cannot silently exceed their remit, treating the trusted internal user as part of the threat model.
Instance Family	concept	Compute Models	A group of instance types sharing a resource profile — general purpose, compute optimised, memory optimised, storage optimised, accelerated — chosen by which resource the workload actually exhausts first.
Integration Coupling Modes	concept	Integration Patterns	The distinct dimensions along which two systems can be coupled — temporal, format, location, semantic — each with its own remedy.
Integration Landscape	concept	Enterprise Integration	The inventory of connections between systems, which is usually larger, less documented and more expensive than the application inventory itself.
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.
Internal Developer Platform IDP, Developer Platform	concept	Internal Developer Platform	The curated set of self-service capabilities that lets product teams build, deploy and operate software without filing tickets against infrastructure.
Interruption Tolerance	concept	Spot & Interruptible Capacity	The property that determines whether a workload can use heavily discounted pre-emptible capacity, defined by what happens when an instance is reclaimed at short notice.
Invalid-Clock Boot Epoch Boot, Clock-Zero Boot, Time-Before-Trust Problem	concept	Physical-World Failure Modes	A device booting with no trustworthy notion of time, which makes certificate validity unverifiable and creates a dependency loop - correct time needs a trusted connection and a trusted connection needs correct time.
Invariant Containment Boundary Follows the Invariant, Transaction Test	concept	Service Boundaries	The rule that a service boundary must contain any invariant that must hold exactly - so discovering that a split would break a transaction is evidence the boundary is wrong, not merely an obstacle.
Invariant-Aligned Partitioning Partition by Invariant, Single-Writer Per Entity	concept	Consistency Models	Choosing the partition key so that every strong-consistency invariant falls entirely inside one partition - which converts distributed coordination into local serialisation.
Inverted Capability Map System-Derived Capability Model, Inventory-Shaped Capability Map	concept	Capability Mapping	A capability map whose boundaries and names were derived from the existing system inventory, so it confirms the current implementation and cannot show that the business needs something it is not organised to do.
Invisible Resource Exhaustion Silent Limit, Unattributed Failure	concept	NAT & Egress	A class of failure where a shared finite resource outside the application's view is exhausted, producing intermittent unexplained errors while every local metric looks healthy.
Jitter	concept	Retries & Backoff	Randomising retry delays so that clients that failed together do not retry together.