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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
Cloud Egress Cost concept Network & Egress Costs The asymmetric pricing where data entering a cloud is free and data leaving is charged, which shapes architecture more than most teams expect.
Cloud Pricing concept Cloud Pricing Models How cloud providers charge, which dimensions dominate, and the pricing structures that reward architectural rather than operational responses.
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.
Cloud Storage concept Cloud Storage Object, block and file storage — with different durability, latency and cost models, and an egress bill that shapes architecture more than most designs admit.
Cluster Multi-Tenancy Soft Multi-Tenancy, Namespace Tenancy concept Platform Tenancy Multiple teams or workloads sharing one cluster, isolated by namespaces, quotas and policy rather than by separate infrastructure.
Cluster Split Axis concept Cluster Architecture The dimension along which the estate is divided into clusters — the single decision that determines both blast radius and operational load.
Coexistence Period concept Coexistence Patterns The interval during which old and new systems both operate and must be kept consistent, which is longer, more expensive and riskier than most plans assume.
Cognitive Load concept Platform Team Topologies The total amount a team must hold in mind to do its work, treated as a hard constraint on how much a team can own.
Cohesion concept Architecture Fundamentals The degree to which everything inside one component belongs together and changes for the same reason.
Cohesion in Practice concept Cohesion Whether the things inside a boundary belong together — measured by whether they change for the same reason and at the same time.
Cold Start at the Edge concept Edge Functions The initialisation delay when a request reaches a location with no warm instance, which at the edge occurs far more often because traffic is spread across many locations.
Collective Communication Cost Allreduce Overhead, Synchronisation Cost at Scale concept Throughput The synchronisation term that determines how far a distributed training or inference job can scale, made of a bandwidth component that is nearly flat in participant count and a latency component that is not.
Command vs Notification Event Semantics, Obligation vs Fact concept Event-Driven Integration Whether a published message requests an action someone is responsible for, or states a fact the publisher does not care who consumes - and why conflating them causes outages.
Commercial Literacy concept Business Understanding Sufficient understanding of how the business makes money and what it is measured on to translate technical work into terms that compete for funding.
Commitment Floor Minimum Spend Obligation, Contracted Spend Floor concept Reserved & Committed Capacity The minimum spend a contract obliges you to pay regardless of usage, which makes efficiency gains unrealisable until the term ends and therefore sets the pace of cost programmes and migrations.
Commitment Read Never Commit From Cache, Authoritative at the Point of Action concept Client Caching & Data Layer The rule that the read immediately preceding an irreversible action must come from the authoritative source, which is what allows everything else in the interface to be aggressively cached.
Common Coupling Shared Mutable State Coupling, Shared Database Coupling concept Coupling Coupling through shared mutable state, where every participant constrains every other participant's ability to change - the one form of coupling with no natural upper bound.
Common-Cause Risk Shared Dependency Risk, Correlated Risk Cluster concept Risk Assessment Methods Several separately scored risks that all fire on the same underlying event, so a register scoring them independently ranks one large loss as a set of medium ones and funds none of them.
Compaction Lag Cleaner Lag, Dirty Segment Lag concept Stream-Table Duality The delay between a key being overwritten and the superseded record actually being removed, which decides how much larger a compacted topic is than its key set and how long a rebuild from it takes.
Compatibility Mode concept Schema Registry The registry setting that defines which schema changes are permitted — backward, forward, full, or none — and therefore what upgrade order is safe.
Compatibility Window Overlap Window, Dual-Version Period concept Platform APIs The period during which two versions of a caller or message must both work, set by deployment and queue mechanics rather than by how many consumers there are, which is why even a single internal consumer requi…
Compensating Manual Control Load-Bearing Workaround, Downstream Correction, Shadow Correction Step concept Legacy Assessment A human step outside a legacy system that corrects its output before anyone consumes it, which means the real specification is the code plus the correction - so a replacement validated against the code alone i…
Compensation Impossibility Irreversible Step, Uncompensatable Action concept Sagas & Compensation The recognition that some saga steps have no true compensating action, and the design rule that follows - order steps by reversibility and gate the irreversible ones.
Complexity Budget concept Reliability vs Complexity The idea that an organisation can operate only a bounded amount of complexity, so each resilience mechanism must justify its share.
Compliance Frameworks concept Compliance Frameworks Externally defined control sets — SOC 2, ISO 27001, PCI DSS and others — whose architectural impact is scope, evidence and segmentation.
Compliance Perimeter Scope, In-Scope Estate concept PCI-DSS Scoping The set of systems subject to a compliance regime - whose size is the dominant cost of that regime, and which is determined by architectural decisions rather than by the assessment.
Composition Accessibility Defect Assembled-Page Accessibility Defect, Integration-Level A11y Failure concept Accessibility Testing An accessibility failure that exists only in the assembled page - focus order, landmark duplication, heading structure, announcement rate - and that every individually conformant component can pass its own che…
Compute Isolation Boundary concept Data Platform Tenancy The line across which one domain's analytical workload cannot affect another's performance, cost attribution or access.
Compute Models concept Compute Models Virtual machines, containers, serverless functions and dedicated hardware — chosen by workload shape rather than by modernity.
Compute Tier Placement concept Edge Compute Topologies Deciding which of on-device, on-premises, metro, regional or central compute a workload belongs to, from its latency, data volume and autonomy requirements.
Concentration Risk Systemic Dependency, Single-Provider Exposure, Vendor Concentration concept Third-Party Risk The exposure created when many organisations, or many parts of one organisation, depend on the same provider - so that a single failure is correlated across the system rather than isolated.
Concern Restatement Tax Layer Tax, Shotgun Surgery concept Separation of Concerns The fixed, permanent cost paid by every feature when architectural layers restate the same concern at several altitudes instead of separating different concerns.
Concurrency concept Concurrency How many operations are in flight at once — the quantity that actually saturates a system, and the one most worth limiting explicitly.
Configuration as Change Config-Code Parity, Data Deployment Rigour, Non-Code Change Control concept Change Management vs CD Applying the review, validation, staging and rollback discipline of code deployment to configuration, content and data updates - because they change production behaviour, ship more often, and are interpreted w…
Configuration Corpus Parity Input Corpus Parity, Config Space Coverage concept Environment Parity How closely the set of configurations a pre-production environment exercises resembles the set production actually carries - the parity dimension that decides whether a config-triggered latent bug is found by …
Configuration Drift concept IaC Modules & Drift The gap that opens between the infrastructure your code describes and the infrastructure that actually exists.
Configuration Over Fork Variation as Data, Single Codebase Multi-Market, Parameterised Localisation concept Regulatory Constraints Expressing per-market or per-tenant differences as configuration data and adapters behind stable interfaces rather than as separate codebases, so that improvements ship everywhere and a new market is mostly a …
Confused Deputy concept Authorization A privileged component tricked into performing an action on behalf of a caller who lacks the authority to perform it directly.
Connascence Connascence of Meaning, Static Connascence concept Cohesion A graded vocabulary for coupling that ranks each dependency by how hard it is to change and how far apart the parties are, so boundaries can be argued with a ranking instead of adjectives.
Connection Fan-In Ephemeral Client Problem, Serverless Connection Storm concept Network Performance The problem created when many short-lived compute instances each require a connection to a stateful dependency that can only support a small number - and the intermediary pattern that resolves it.
Connection Migration Session Continuity, Seamless Handover concept WebSockets & Realtime Keeping a logical session alive when the underlying network path changes - either in the transport, or reconstructed by the application after a reconnect.
Connection Pinning Sticky Connection Imbalance, L4 Balancing of Multiplexed Protocols concept gRPC APIs The traffic imbalance that appears when a layer-4 balancer distributes long-lived multiplexed connections instead of requests, so new backend capacity receives no traffic until clients reconnect.
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 Ring Hashing concept Partitioning & Sharding A partitioning scheme where adding or removing a node moves only a small fraction of keys, instead of remapping everything.
Consistent Prefix Read concept Consistency Models A guarantee that if a sequence of writes happens in a given order, a reader sees a prefix of that sequence — never an out-of-order subset.
Constraint Removal Risk Chesterton's Fence, Load-Bearing Friction, Safety-Providing Limit concept Systems Thinking The hazard that a limit, gate or slowness being removed was accidentally preventing something nobody documented - so the improvement's cost lands somewhere unrelated and later.
Consumer Contract concept Consumer-Driven Contracts A machine-readable record of exactly which parts of a provider's response one consumer relies on, generated from that consumer's own tests.
Consumer Group concept Event Streaming A set of consumers that cooperatively read one stream, with each partition assigned to exactly one member, so the group collectively processes every message once.
Consumer Liveness Gap Zombie Consumer, Progress Blindness concept Competing Consumers The interval in which a queue consumer is alive by every health signal yet is making no progress, so its share of the work stalls while pool-level metrics stay normal.
Container Image concept Containers A layered, content-addressed filesystem bundle plus metadata, from which containers are instantiated — immutable by construction and identified by digest.
Containment vs Eradication concept Security Incident Response Stopping an attacker's ongoing access versus removing their foothold entirely — sequential phases with different urgency and different risks of doing them wrong.
Content-Channel Release Path Data Channel Deployment, Ungated Update Path concept Quality Gates Any route by which an artefact reaches a running system without passing the gates that code passes - remote config, feature flags, rules tables, models, CDN rules, detection content - and which therefore carri…
Contention Blind Spot Single-User Environment Blindness, Concurrency Fidelity Gap concept Developer Environments The class of defects a one-user test environment cannot exhibit at all - lock waits, pool exhaustion, races and plan flips - because they require concurrency and production-shaped data rather than correct code.
Context Window concept AI-Era Architecture The maximum number of tokens a model can attend to in one request, holding the system prompt, history, retrieved context, tools and the answer.
Context Window Budget concept LLM Application Architecture The finite token allowance per request, treated as an engineering resource to be allocated deliberately between system instructions, retrieved context, history and output.
Contract Event Designed Event vs Row Change, Deliberate Emission concept Outbox An event a system deliberately emits with a schema it owns and a meaning it controls, as opposed to a captured row change that exposes the producer's table structure as a public interface.
Control Coverage Assurance Coverage, Estate Coverage concept Continuous Controls Monitoring The proportion of the actual estate a control operates on - the metric that determines whether monitoring provides assurance or false confidence.
Control Design vs Operating Effectiveness concept Control Design vs Operation The distinction between a control being correctly designed to address a risk and it actually having worked consistently over a period.
Control Plane and Data Plane concept Cloud Architecture The separation between the machinery that makes changes to a system and the machinery that serves its traffic.
Control Plane vs Data Plane concept Cloud Architecture The separation between the system that manages configuration and the system that serves requests, which have very different reliability requirements.