system-architecture-design

# System Architecture Design Acknowledgement: Shared by Peter Bamuhigire, techguypeter.com, +256 784 464178. <!-- dual-compat-start --> ## Use When - Use when defining or reviewing software architecture for web apps, mobile backends, SaaS platforms, APIs, distributed systems, or major features. Covers bounded contexts, module decomposition, contracts, failure handling, ADRs, and scalability tradeoffs. ## Do Not Use When - The request is limited to an isolated endpoint, query, UI component, or deployment script with no system-level trade-off. - The architecture is already decided and the task only needs implementation; use the relevant engineering skill and preserve recorded decisions. ## Required Inputs | Input | Required | Why it matters | |---|---|---| | Business capabilities and critical journeys | yes | Anchors boundaries in real system responsibilities | | Quality attributes with measurable scenarios | yes | Makes performance, security, availability, and changeability testable | | Constraints and existing-system context | yes | Prevents an unbuildable greenfield design | | Scale, data, integration, and deployment assumptions | conditional | Supports sizing and topology decisions | ## Workflow Clarify drivers and constraints, model context and containers, assign data and responsibility boundaries, compare viable options, record decisions, then test the design against failure, evolution, security, and operational scenarios. ## Quality Standards Decisions link a d...