Terminology

2240 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 areas2240 Architecture Fundamentals77 Distributed Systems107 Data Architecture110 Cloud Architecture94 Networking88 API & Integration Architecture82 Reliability & Resilience80 Observability75 Performance & Capacity Engineering72 Security Architecture86 Cost Architecture & FinOps71 Business Architecture67 Architecture Communication67 Enterprise Architecture66 Legacy Modernization71 AI-Era Architecture74 Software Architecture & Engineering71 Architecture Patterns71 Architecture Decision-Making63 The Architect's Meta-Skills61 Delivery & Release Engineering66 Platform Engineering & Developer Experience70 Testing & Quality Architecture71 Data Platform Architecture69 Streaming & Real-Time Data69 Data Governance & Semantics74 Frontend & Experience Architecture66 Edge, Mobile & IoT68 Regulatory & Data Protection Architecture65 Assurance, Audit & Model Risk69

Kind Any concept806 practice738 pattern379 metric133 case-study77 tool62 protocol45

5 terms shown.

Term	Kind	Topic	What it is
Late-Data Policy Lateness Handling, Allowed Lateness	practice	Watermarks & Late Data	The explicit decision about what happens to an event that arrives after its window has closed - drop it, route it aside, or update the emitted result.
Provisional Result Restatement, Unsettled Aggregate	concept	Watermarks & Late Data	An aggregate emitted before its window is definitively complete, which may be corrected when late events arrive - correct behaviour that destroys trust when it is not made visible.
Watermark Event-Time Progress, Completeness Estimate, Lateness Boundary	concept	Watermarks & Late Data	A heuristic assertion that no further events earlier than a given event time are expected, which is how a stream processor decides when a window is complete - and therefore where the correctness-versus-promptn…
Watermark	concept	Watermarks & Late Data	The stream processor's assertion that no further events older than a given event time are expected, which is what allows a window to close.
Watermark Lag	metric	Watermarks & Late Data	How far behind the newest event a watermark is held, which trades result latency against how much late data is included.