name: tech-evaluator
description: Serves /genesis Step 3 "Technical selection": evaluates candidate stacks with ATAM and a 12-dimension weighted matrix, producing traceable comparison conclusions and ADR promotion material; does not author formal ADR files (persisted in Step 5). Prefer references/ beside this SKILL.
Technical Evaluator Handbook — Genesis Step 3
"There is no best technology stack—only the most suitable stack." — ThoughtWorks Technology Radar
This skill is grounded in SEI ATAM (Architecture Tradeoff Analysis Method) and weighted decision matrices. In /genesis it binds as Step 3; formal ADR authoring and numbering are governed by Step 5 and genesis.md.
CRITICAL /genesis gates (this track only)
[!IMPORTANT]
/genesis Step 3: Only output evaluation results and Markdown comparison material; must not in this step create or modify any ADR file under .anws/v{N}/03_ADR/. Rationale is in genesis.md Step 3 / Step 5: ADRs are formal decision records and must land after full review in Step 5.- Step 5 persistence targets (for downstream reference, not Step 3 work): elevate the Step 3 comparison table into
.anws/v{N}/03_ADR/ADR_001_TECH_STACK.md (and sibling ADRs); section structure is authoritative in references/ADR_TEMPLATE.md only.
- If the host session declares it is not
/genesis or explicitly authorizes "write ADRs in this step," follow that workflow on the spot; by default Step 3 still does not write ADRs.
[!NOTE]
ADR timing: Step 3 outputs evaluation + comparison material only—no 03_ADR/; Step 4 yields boundaries + 02_*; Step 5 promotes ADRs so impact aligns with real system IDs. Full table and four-point rationale: genesis.md Step 3 NOTE. Non-/genesis or explicit “write ADR in this step” overrides defaults.
CRITICAL spec delivery contract (Step 3 artifacts)
[!IMPORTANT]
- Verifiable: Constraint blocks must cover functional requirements, non-functional requirements, team, budget, and special constraints; for missing items write "Not provided—evaluation assumes H-…"; silent omission is not allowed.
- Countable: Each candidate stack must have a 12-dimension score table (1–5) or per-dimension "N/A + reason"; totals without a dimension breakdown are not allowed.
- Deducible: ATAM paragraphs must include at least one quality-attribute scenario, several trade-off points, and several risk points; stacking adjectives is not allowed in place of scenarios.
- Promotable: The final comparison table must map cleanly onto
references/ADR_TEMPLATE.md sections and required fields for paste and polish in Step 5.
- Explicit verification strategy: Must answer or mark open: emphasis for unit / integration / E2E tests, smoke / regression gates, and which layer owns quality gates—PR / INT / staging / release (consistent with Step 3 in
genesis.md).
- Single source of truth: Numbers and conclusions are anchored to Step 3 output; Step 5 only edits and changes status—it must not re-score backward without new evidence.
Mandatory deep thinking
[!IMPORTANT]
Before evaluating you must invoke the sequential-thinking skill and organize 3–7 thoughts by complexity—for example:
- What are the user's core scenarios and must-support use-case boundaries?
- Team familiarity and acceptable learning cost?
- Budget and sensitivity to cloud / license TCO?
- Expected scale and concurrency / data volume?
- Do compliance regimes (GDPR, classified protection, etc.) veto certain stacks?
Goals (Step 3)
Without writing ADR files, produce:
- Structured constraint summary and candidate stack list.
- 12-dimension scoring matrix and weighted aggregate explanation (declare weights or use the suggestions here and justify).
- Short ATAM trade-offs and risks narrative.
- A Markdown master comparison table of candidates usable directly in Step 5.
Evaluation flow (the evaluation)
Step 1: Gather constraints
Must obtain from the user or loaded artifacts (label assumptions per spec when incomplete):
- Functional requirements: core capability list (may cite
01_PRD.md).
- Non-functional requirements: performance, availability, security level.
- Team: headcount, skills, appetite to learn.
- Budget: dev, ops, time.
- Special constraints: compliance, legacy integration, mandated technologies.
- (If Step 2.5 ran) Evidence and alternatives from
/explore research.
What to do
Fix input boundaries and list gaps with hypothesis IDs.
Why
Avoid preference scoring without constraints and unreproducible conclusions.
How to validate
Outputs may include a "hypothesis H-xx" cross-reference table; no silent gaps.
Step 2: Identify candidates
Mainstream stack reference (replace or extend per project):
| Scenario | Recommended stack | Alternatives |
|---|
| Web full-stack | Next.js + TypeScript | Nuxt, SvelteKit |
| Backend API | Go / Rust / Node.js | Python FastAPI, Java Spring |
| Desktop | Tauri (Rust + Web) | Electron, Flutter Desktop |
| Mobile | React Native / Flutter | Swift/Kotlin native |
| AI/ML | Python + PyTorch/TensorFlow | Rust (Candle), Julia |
| Data-heavy | PostgreSQL + TimescaleDB | ClickHouse, DuckDB |
What to do
List two or more named candidates (language / framework / key middleware) with one line stating scope.
Why
Single candidate yields no trade-off and cannot satisfy ATAM.
How to validate
Each candidate is scored independently; no anonymous "option A/B."
Step 3: 12-dimension evaluation
Score each candidate 1–5 per dimension:
| Dimension | Weight hint | Evaluation question |
|---|
| Requirement fit | — | Covers all core functionality? |
| Scalability | — | Supports 10x growth? |
| Performance | — | Meets latency / throughput? |
| Security | — | Built-in security and compliance support? |
| Team skill | — | Familiarity and learning curve? |
| Talent market | — | Hiring and outsource availability? |
| Development speed | — | Iteration and delivery velocity? |
| TCO | — | Dev + ops + licensing? |
| Community/ecosystem | — | Libraries, tools, troubleshooting assets? |
| Long-term maintenance | — | Shelf life and LTS? |
| Integration | — | Legacy and third-party integration? |
| AI readiness | — | Ease of wiring AI / LLMs? |
What to do
Complete the matrix; declare weights (even or weighted) and compute comparable totals or tiers.
Why
Dimensional transparency aids ADR evidence in Step 5.
How to validate
Tables are recalculable in Markdown; N/A dimensions get a single-line rationale.
Step 4: Trade-off analysis (ATAM)
- Identify quality-attribute scenarios (e.g., "Under 1k concurrent users, P95 < 200 ms").
- Grade each candidate's support for the scenario.
- List trade-offs (e.g., performance vs team learning cost).
- List risks (e.g., maturity of a new framework).
What to do
Say clearly why runner-up lost.
Why
ADR value is trade-offs and consequences, not merely declaring a winner.
How to validate
At least one scenario plus several trade-offs / risks cross-referenced with candidate tables.
Step 5: Produce ADR promotion material (Step 3—not persisted)
Under /genesis Step 3 you must not create or modify 03_ADR/*.md. Produce full Markdown comparison conclusions and promotion material so Step 5 can elevate losslessly against references/ADR_TEMPLATE.md; sections may read Proposed / TBD.
If the workflow rarely demands placeholder files this step, only empty files or MANIFEST paths are allowed—do not treat placeholders as accepted ADRs.
Forbidden: embed another full ADR exemplar in this SKILL that duplicates references/ADR_TEMPLATE.md; any section question defers to that file.
What to do
Produce full comparison + draft Markdown scoped to references/ADR_TEMPLATE.md (in memory / session).
Why
Align with genesis decision checkpoints; avoid early informal ADRs.
How to validate
The parent agent can open references/ADR_TEMPLATE.md in Step 5 and align sections without information breaks.
Practitioner rules
- Prefer "boring" tech: choose mature stacks unless there is strong reason not to.
- Limited innovation budget: 1–2 innovation slots per project; keep the rest conservative.
- Team capability wins: the best technology is zero value if it cannot be wielded.
- TCO is not cash alone: time and cognitive load count.
references and bundle paths
This bundle ships references/ADR_TEMPLATE.md beside this SKILL. Read only references/ next to this SKILL.
| File | Purpose |
|---|
references/ADR_TEMPLATE.md | ADR shape and required sections |
Execution shape and subagent orchestration
What to do
- Preferred: When the host provides AGENTS / subagents, you may delegate candidate discovery, per-candidate multidimensional drafts, or ATAM risk sketches; the orchestrator issues this doc's spec contract + gates + ADR template fields, then merges into one consolidated draft.
- Parent agent:
sequential-thinking must run one full chain in the main session or a designated merge agent before locking; subagents cannot replace that duty unless the workflow states otherwise.
- Fallback: Without subagents, the current session runs the whole flow end to end.
Why
Parallel discovery and serialized decisions reduce gaps across dimensions.
How to validate
Merged draft still meets spec; no contradictory scores or duplicate candidate names; /genesis Step 3 still performs no 03_ADR writes.
Handoff checklist (orchestration / subagents / Step 5)
<completion_criteria>
sequential-thinking completed with 3–7 thoughts visible in output and absorbed by the evaluation.- Deliverables meet CRITICAL spec delivery contract (verifiable / countable / deducible / promotable / explicit verification strategy).
- On the default
/genesis Step 3 path, no ADR persisted under .anws/v{N}/03_ADR/.
- Handoff checklist holds or exemptions are logged in the final section "Open items".
- Use the workspace
.agents/skills/ tree consistently with other skills in the session.
</completion_criteria>
