docs: add Practitioner Insights section with Dave Van Veen reference

- New section 11.2 Practitioner Insights (guide/ai-ecosystem.md:1209)
- Dave Van Veen (PhD Stanford, Principal AI Scientist @ HOPPR)
- Validates guide patterns: TDD, worktrees, manual commits, planning
- Academic credential: Co-author "Agentic Systems in Radiology" (ArXiv 2025)
- Clarification: "English is new programming language" = Karpathy/Reddy
- Updated reference.yaml with deep_dive + ecosystem entries
- Updated CHANGELOG.md

Co-Authored-By: Claude <noreply@anthropic.com>

CHANGELOG.md

@@ -53,6 +53,19 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - `ai_ecosystem_goose: "guide/ai-ecosystem.md:1116"`
   - `ai_ecosystem_goose_comparison: "guide/ai-ecosystem.md:1132"`
 
+- **Practitioner Insights section** (`guide/ai-ecosystem.md:1209-1241`)
+  - New section "11.2 Practitioner Insights" for external validation
+  - Dave Van Veen (PhD Stanford, Principal AI Scientist @ HOPPR)
+  - Validates guide patterns: TDD, git worktrees, manual commits, planning phase
+  - Academic credential: Co-author "Agentic Systems in Radiology" (ArXiv 2025)
+  - Clarification: "English is the new programming language" attributed to Karpathy/Reddy, not Van Veen
+  - Updated Table of Contents with new section
+
+- **machine-readable/reference.yaml**: Practitioner insights entries
+  - `practitioner_insights: "guide/ai-ecosystem.md:1209"`
+  - `practitioner_dave_van_veen: "guide/ai-ecosystem.md:1213"`
+  - `ecosystem.practitioner_insights.dave_van_veen` with full metadata
+
 ### Changed
 
 - **Subscription limits section** (`guide/ultimate-guide.md`) rewritten with concrete data

guide/ai-ecosystem.md

@@ -21,6 +21,7 @@
 - [10. Claude Cowork (Research Preview)](#10-claude-cowork-research-preview)
 - [11. AI Coding Agents Matrix](#11-ai-coding-agents-matrix)
 - [11.1 Goose: Open-Source Alternative (Block)](#111-goose-open-source-alternative-block)
+- [11.2 Practitioner Insights](#112-practitioner-insights)
 - [12. Context Packing Tools](#12-context-packing-tools)
 - [Appendix: Ready-to-Use Prompts](#appendix-ready-to-use-prompts)
 - [Alternative Providers (Community Workarounds)](#alternative-providers-community-workarounds)
@@ -1206,6 +1207,41 @@ For most developers already invested in Claude Code workflows, the switching cos
 
 ---
 
+## 11.2 Practitioner Insights
+
+External resources from experienced practitioners that validate and extend the patterns documented in this guide.
+
+### Dave Van Veen (Stanford PhD, HOPPR)
+
+**URL**: [davevanveen.com/blog/agentic_coding/](https://davevanveen.com/blog/agentic_coding/)
+
+**Author credentials**:
+- PhD in Machine Learning, Stanford University (2021-2024)
+- Principal AI Scientist at HOPPR (TB-scale medical AI pipelines)
+- Co-author: "Agentic Systems in Radiology" (ArXiv 2025)
+
+**Content summary**: Production-grade agentic coding workflow with 6 guardrails:
+- **TDD** (Test-Driven Development)
+- **Simplicity first** / **YAGNI**
+- **Reuse before rewriting**
+- **Worktree safety** (git isolation)
+- **Manual commits only** (human authorship boundary)
+
+**Alignment with this guide**: All patterns are covered in our documentation (often with more depth):
+
+| Van Veen Pattern | This Guide Reference |
+|------------------|---------------------|
+| TDD guardrail | `guide/methodologies.md` (TDD, Verification Loops) |
+| Git worktrees | `examples/commands/git-worktree.md` (+ DB branching) |
+| Planning phase | Plan Mode (Section 3.3) |
+| Manual commits | Git best practices (Section 9.9) |
+
+**Value**: Independent validation from a Stanford PhD practitioner that the patterns in this guide are production-ready. Useful for readers seeking multiple authoritative sources.
+
+**Note**: The phrase "English is the new programming language" (sometimes attributed to this article) originates from Andrej Karpathy and Bindu Reddy, not Van Veen.
+
+---
+
 ## 12. Context Packing Tools
 
 When working with LLMs on large codebases, **context packing** refers to techniques for extracting and feeding relevant code context to the model efficiently.

machine-readable/reference.yaml

@@ -113,6 +113,9 @@ deep_dive:
   verification_loops_source: "https://www.anthropic.com/engineering/claude-code-best-practices"
   eval_harness: "guide/methodologies.md:161"
   eval_harness_source: "https://www.anthropic.com/engineering/demystifying-evals-for-ai-agents"
+  # Practitioner Insights (external validation)
+  practitioner_insights: "guide/ai-ecosystem.md:1209"
+  practitioner_dave_van_veen: "guide/ai-ecosystem.md:1213"
   # DevOps/SRE Guide (guide/devops-sre.md)
   devops_sre_guide: "guide/devops-sre.md"
   devops_fire_framework: "guide/devops-sre.md:50"
@@ -488,6 +491,14 @@ ecosystem:
       agents_snapshot: 23  # As of 2026-01-19 (evolves over time)
       positioning: "Discovery tool - Use Matrix to find/compare agents, use this guide to master Claude Code"
       note: "External resource - verify data freshness as agents/criteria evolve"
+  practitioner_insights:
+    dave_van_veen:
+      url: "davevanveen.com/blog/agentic_coding/"
+      author: "Dave Van Veen (PhD Stanford, Principal AI Scientist @ HOPPR)"
+      focus: "Production-grade agentic coding guardrails (TDD, worktrees, manual commits)"
+      academic: "Co-author 'Agentic Systems in Radiology' (ArXiv 2025)"
+      alignment: "Validates patterns already documented in this guide"
+      guide_section: "guide/ai-ecosystem.md:1209"
   install_templates: "scripts/install-templates.sh"
   cowork:
     description: "Claude Code for non-developers (desktop app)"