Architect's Reference Matrix

Definition

A 4×4 lookup table mapping the four architectural constraints (rows) against the four problem domains (columns), naming the go-to pattern for each intersection.

Key points

• Columns (domains): Data Extraction, Customer Support, Developer Productivity, Multi-Agent.
• Rows (constraints): Token Bloat, Latency, Compliance/Control, Accuracy.

• Blank cells are left empty on the slide (no dedicated pattern for that intersection).
• Each cell links to a concept: Filter Stale Results / Scratchpad File / Shared Vector Store · Batch Routing / Parallelization & Caching · App-Layer Intercepts / tool_choice Enforcement · Schema Redundancy / Granular MCP Tools / Structured Intermediates.

Why it matters for the exam

• README study focus item. It is the deck's "index" — memorizing which pattern solves which constraint-in-which-domain is high-yield.

Common gotchas

• The matrix has intentional blanks — don't invent a pattern for an empty cell.
• Rows are constraints, columns are domains; keep the axes straight.

See also

• Routing for cost and SLA
• Resilient schema design
• Structured Intermediate Representations
• The Production Architecture Blueprint

Sources

• architects-playbook
• netlight-study-guide