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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

2205 terms shown.

Term Kind Topic What it is
Extraction Payback Period metric Monolith vs Microservices The time it takes for the coordination cost a service extraction removes to repay the one-off extraction cost plus the permanent cost of running one more deployable - which is usually never unless the module h…
Facilitation practice Facilitation Running a discussion so that a group reaches a decision — a distinct skill from having the best answer.
Facilitation Neutrality practice Facilitation Separating the role of running a discussion from the role of advocating within it, because one person cannot do both credibly.
Fact Grain Multiplication Join Fan-Out, Dimension Row Explosion concept Slowly Changing Dimensions Silent duplication of fact rows when a fact is joined to a versioned dimension without an effective-date predicate, inflating every additive measure in proportion to how often dimension members change.
Fail-Closed Classification Default Untagged-Is-Restricted, Deny-On-Missing-Label pattern Data Classification Resolving an absent sensitivity label to the most restrictive class, so that forgetting to classify data produces a denied query rather than a silent exposure.
Fail-Closed Control Deny on Error, Safe-Failure Gate practice Control Design vs Operation A control that blocks when it cannot evaluate, rather than allowing the action through - so that a broken control is visible immediately instead of silently ceasing to protect anything.
Fail-Fast vs Fail-Safe concept Failure Modes Whether a component should stop immediately on detecting a problem, or continue in a degraded but safe mode — a choice that depends entirely on which outcome is worse.
Fail-Open Audit Boundary Audit Fail-Open Rule, Accountability Degradation Policy pattern Healthcare Data Protection A pre-declared rule saying which classes of access may proceed when the audit trail cannot be written and which must be refused, so a logging failure does not become a safety failure or an invisible one.
Failback practice Disaster Recovery Returning to the primary region after a failover, including reconciling the data written while it was unavailable — the half of DR that is usually unplanned.
Failover pattern Failover Switching to a standby when the primary fails — where detection, fencing and the decision to automate are harder than the switch itself.
Failover Orchestration pattern Failover The sequence of detection, decision, promotion and traffic redirection that moves service from a failed component to a healthy one.
Failover Propagation Delay Client Convergence Time, Failover Tail metric Failover The interval between a failover completing on the server side and the last client actually using the new location, which is usually the larger part of the recovery time users experience.
Failure Domain Annotation Shared-Fate Labelling practice Deployment Diagrams Writing on a deployment diagram what each group of nodes shares - image, configuration source, pipeline, control plane - so the diagram answers what fails together rather than only where things run.
Failure Injection Testing practice Resilience Testing Deliberately introducing faults into a system under test to verify that timeouts, retries, fallbacks and circuit breakers behave as designed.
Failure Thinking Pre-mortem, Failure Analysis practice Failure Thinking The habit of asking what happens when each part fails, applied systematically during design rather than during the incident.
Failure Threshold concept Circuit Breakers The condition that trips a circuit breaker — best expressed as a failure rate over a rolling window with a minimum request volume, not as a consecutive-failure count.
Fairness Definition Choice Incompatible Fairness Metrics, Which Fairness concept Bias & Fairness Controls The unavoidable selection between mathematically incompatible fairness definitions - a legal and business determination that a team makes implicitly if it does not make it explicitly.
Fairness Through Unawareness Blindness Approach, Attribute Removal concept Bias & Fairness Controls The mistaken belief that removing a protected attribute from a model's inputs prevents disparate outcomes, when correlated features still carry the attribute and the deletion usually destroys the ability to me…
Fake Drift Virtualisation Divergence, Stale Mock concept Service Virtualisation The divergence between a simulated dependency and the real one it stands in for - which makes tests pass while the real integration fails, producing confidence rather than caution.
Fallback Independence practice Graceful Degradation The requirement that a degraded path fail independently of the primary - and be exercised continuously, because fallbacks that are never run do not work.
Fallback Strategy pattern Circuit Breakers What a caller does instead when a circuit breaker is open — the part of the pattern that determines whether failing fast helps anyone.
False Analogy concept Pattern Recognition Applying a pattern learned in one context to a superficially similar situation whose relevant properties differ.
False-Decline Cost Cost of the False Positive, Friction Loss metric Security vs Usability The value lost to legitimate customers rejected or deterred by a control - invisible in fraud metrics, frequently larger than the losses prevented, and the number that turns a values argument into arithmetic.
Falsification Trigger Decision Invalidation Condition, Wrongness Condition practice Judgement Under Uncertainty A named signal and threshold written into a decision at the moment it is made, with an owner, so that telemetry rather than memory tells anyone whether the decision is still correct.
Fan-Out concept Distributed Systems One incoming request causing many outgoing ones, which multiplies both load and tail latency.
Fan-Out Amplification Broadcast Multiplication, Subscriber Amplification concept WebSockets & Realtime The property that one input event becomes as many output events as there are subscribers, making the workload proportional to audience size rather than to event rate - and the reason broadcast paths cannot sha…
Fan-Out Delivery pattern Publish/Subscribe Delivering one published message to many independent subscribers, each with its own copy, position and failure handling.
Fan-Out Latency Amplification concept Tail Latency The effect by which a request that depends on many parallel sub-requests is governed by the slowest of them, so rare slowness becomes common at the user level.
Fan-out on Write vs Fan-out on Read Push vs Pull Timelines concept Messaging & Queues Whether an event is copied to every recipient's store at publish time, or assembled from sources at read time - and why large systems need both.
Fan-out Threshold Celebrity Threshold, Hybrid Fan-out Switch practice Publish/Subscribe The membership or follower count at which a system switches from pushing to recipients to having recipients pull - and the monitoring that keeps the classification correct.
Fault Domain concept Fault Isolation A boundary within which a single failure is contained, defined by the infrastructure and dependencies that components inside it share.
Fault Tolerance concept Distributed Systems Continuing to operate correctly despite the failure of some components, by design rather than by luck.
Feature Criticality Tiering practice Graceful Degradation Classifying product functionality by whether it must work, should work, or can be dropped, so degradation decisions are made in advance by the business.
Feature Flag Feature Toggle pattern Progressive Delivery A runtime switch that separates deploying code from releasing behaviour.
Feature Flags Feature Toggles pattern Feature Flags Decoupling deployment from release, so code ships continuously and exposure is a runtime decision — with a lifecycle that must be enforced.
Feature Freshness metric Feature Freshness How recent the data behind a model's input features is at the moment of inference, and the training-serving consistency problem it creates.
Feature Parity Trap concept Rebuild vs Re-architect The expectation that a replacement system must match every behaviour of the old one before it can be adopted, which is what makes rewrites never finish.
Feature Staleness metric Feature Freshness The age of the feature values a model scores against, and the divergence between how they are computed at training time and at inference time.
Feature Store tool ML Platform A system that computes, stores and serves model input features consistently for both training and inference, eliminating training-serving skew.
Feedback Loop concept Systems Thinking A circular causal chain in which an effect influences its own cause, producing behaviour that cannot be understood by examining components in isolation.
Fencing Token pattern Distributed Locking A monotonically increasing number issued with a lock, checked by the resource, so a holder whose lease expired cannot act on stale authority.
Field Data Versus Lab Data concept Real User Monitoring The difference between what real users on real devices experience and what a synthetic run measures, and why the second is systematically optimistic.
Field-Level Encryption Application-Level Encryption pattern Encryption Encrypting specific sensitive fields in the application before they reach the datastore, so the store never holds plaintext.
Figma's Postgres Sharding case-study Data Architecture Figma delayed sharding for years using replicas and vertical partitioning, then sharded Postgres horizontally without downtime using logical shards and a proxy layer.
File-Based Integration pattern Legacy Integration Exchanging data as files on a schedule via SFTP or shared storage — dated, still ubiquitous, and workable when its failure modes are handled explicitly.
Filter Composability concept Pipes and Filters The property that makes a pipeline style work — each stage transforms input to output with no shared state, so stages can be reordered, reused and scaled independently.
Filtered Vector Search Predicate-Constrained ANN, Metadata Filtering in ANN pattern Vector Databases Combining a metadata predicate with approximate nearest-neighbour search - where the predicate's selectivity, not the corpus size, decides whether results are correct or latency collapses.
Financial Services Regulation concept Financial Services Regulation Architecture under financial regulation — where record-keeping, demonstrable resilience, and the ability to exit a provider are structural requirements.
FinOps practice Cost & FinOps The practice of giving engineering teams visibility into and accountability for the cost of what they build and run.
FinOps Operating Phases practice FinOps Practice The inform, optimise and operate cycle through which an organisation builds cost management into normal engineering practice.
FinOps Practice practice FinOps Practice The operating model that makes cost a continuous engineering concern rather than a periodic finance exercise.
Firewalls and Security Groups concept Firewalls & Security Groups Network-level access control, its real value as a second layer, and why the perimeter model stopped being sufficient.
First Principles Thinking practice First-Principles Reasoning Reasoning from what must be true rather than from what is usually done — the technique for problems where precedent is unavailable or misleading.
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.
Fitness Function Drift Vacuous Check, Silent Rule Decay concept Fitness Functions The failure mode in which an architecture check keeps passing after it has stopped examining anything, so a green build certifies a rule that is no longer enforced.
Flag Change Provenance Flag Audit Trail, Configuration Provenance practice Feature Flags Recording who changed a flag, when, from what to what - and, separately, stamping the effective configuration version onto every artefact it influenced, because the first cannot reconstruct the second.
Flag Debt concept Feature Flags The accumulating complexity of feature flags that are never removed, producing untested code paths and combinatorial behaviour nobody understands.
Flag Evaluation Latency concept Client Feature Flags The delay between page load and the client knowing which variant to show, which produces a visible flicker unless the flag is resolved before render.
Flag Expiry Discipline Flag Lifecycle, Stale Flag Removal practice Feature Flags Creating every flag with an owner and an expiry date and treating removal as part of the rollout's definition of done - because flags have a creation process and, without this, no removal process.