Terminology

384 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 areas384 Architecture Fundamentals16 Distributed Systems73 Data Architecture71 Cloud Architecture17 Networking13 API & Integration Architecture17 Reliability & Resilience16 Observability14 Performance & Capacity Engineering13 Security Architecture18 Cost Architecture & FinOps12 Business Architecture9 Architecture Communication8 Enterprise Architecture8 Legacy Modernization11 AI-Era Architecture15 Software Architecture & Engineering19 Architecture Patterns15 Architecture Decision-Making11 The Architect's Meta-Skills8

Kind Any concept136 practice90 pattern81 case-study26 protocol19 tool19 metric13

16 terms shown.

Term	Kind	Topic	What it is
Availability Calculation	concept	Reliability & Resilience	Deriving a system's availability from its components, remembering that dependencies in series multiply.
Blameless Postmortem	practice	Reliability & Resilience	An incident review that seeks the systemic conditions that made a failure possible, explicitly excluding individual fault.
Capacity Planning	practice	Reliability & Resilience	Deciding in advance how much capacity will be needed, given growth, seasonality and failure scenarios, and ensuring it can be there in time.
Chaos Engineering	practice	Reliability & Resilience	Deliberately injecting failure into a system to discover, before an incident does, which of your resilience assumptions are false.
Disaster Recovery DR	practice	Reliability & Resilience	The plan and capability for restoring service after an event that takes out a whole site, region or system.
Error Budget	metric	Reliability & Resilience	The amount of unreliability an SLO permits, treated as a resource that feature velocity spends.
Error Budget Policy	practice	Error Budgets	The written agreement about what happens when the error budget is exhausted, which is what turns an SLO from a number into a control.
Game Day	practice	Reliability & Resilience	A scheduled exercise in which a failure is deliberately introduced and the team responds as though it were real, to test the system and the response together.
Incident Command Incident Command System, ICS	practice	Reliability & Resilience	Assigning explicit roles during an incident — commander, operations lead, communications lead, scribe — so coordination does not compete with diagnosis.
Redundancy	concept	Reliability & Resilience	Having more instances of a component than the load requires, so that failures can be absorbed without loss of service.
RTO and RPO Recovery Time Objective, Recovery Point Objective	metric	Reliability & Resilience	How long recovery may take (RTO) and how much data may be lost (RPO), the two numbers that determine the cost of a resilience design.
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.
Severity Levels SEV Levels	practice	Reliability & Resilience	A predefined scale of incident impact that determines who is woken, how fast, and what process applies.
Static Stability	concept	Reliability & Resilience	The property that a system keeps working on its existing state when its control plane or dependencies are unavailable, rather than needing them to keep running.