Data Scientist · L1100 · 2026-07-18

Slice data-scientist/1100 · Level 1100 (Data Engineering) · Master ⚡ tier · Engine verdict ⚠️ warn · Walked 2026-07-18

🔗 Perfection run · 🏠 Perfection dashboard · 📄 Raw report · 🕘 Change history

🎯 Session Summary

I walked the first window (5 of 15 quests) of the Data Scientist → Level 1100 “Data Engineering” (Master ⚡) slice as a learner, driving the agentic execute engine over each quest in a disposable sandbox and then reasoning about the linked journey by reading each quest’s source. Headline verdict: warn — average 68.8%, with 1 pass, 3 warn, 1 fail. Every quest’s conceptual content is sound and everything ran safely (safety scored 5/5 across all five), but four of the five quests contain at least one concrete, reproducible defect that stops a learner cold if they copy-paste literally — a Jinja {​% raw %​} escaping leak, a broken watermark SQL column, BSD-only sed/default-branch assumptions, a mismatched “Expected” output line, and missing setup steps.

The most actionable takeaways for a maintainer: fix The Temple of Templates (the fail, 56%) where literal {​% raw %​}/{​% endraw %​} artifacts break every Jinja snippet, and fix the two high-severity accuracy bugs in ETL Pipeline Design (broken updated_at watermark) and Mastering Version Control (BSD sed -i '' + git init defaulting to master). Note also that this “slice” is a level band, not a dependency chain — the five quests come from five different quest series, so continuity is thematic, not prerequisite-linked (see §6).

🗺️ The Journey

🔬 Evidence

All evidence below is from commands actually run by the execute engine in a disposable sandbox (per walk-evidence.json), except where labeled reasoned (judged statically) or skipped (not run — no macOS/Windows/auth/heavy-install available).

1. The Warden Pact — 78% (warn) · ran 14 snippets, 11 passed / 3 failed / 3 reasoned

• ./warden.sh format-and-lint src/app.js → passed: ✅ ALLOWED: format-and-lint is L4 — autonomous, audit-logged (exit 0), matches docs.
• ./warden.sh implement-feature src/routes/signup.ts → passed: ⏸️ WAITING… (exit 78); APPROVED=yes … → ✅ ALLOWED (gated)… (exit 0). Both match docs.
• ./warden.sh edit-database-migration database/migrations/001.sql → failed: actual output 🚫 REFUSED: database/migrations/001.sql is inside forbidden path database/migrations/ (exit 1), not the quest’s documented 🚫 REFUSED: edit-database-migration is L0 — never the agent's call. Exit code matches; the message a learner diffs does not.
• agent-audit-trail.yml heredoc extracted and run → failed: audit entry is written across 7 physical lines, not the single-line-per-entry JSONL the prose explicitly claims and justifies (“one JSON object per line you can grep”).
• Attack calls (format-and-lint .github/workflows/deploy.yml, casually-drop-the-database prod.sql) → both passed, refused as documented. All 4 YAML config blocks parse after stripping Liquid {​% raw %​} tags.

2. Mastering Version Control — 62% (warn) · ran 5 / passed 1 / failed 4 / skipped 3 / reasoned 16

• Chapter 1 “```bash” block containing fix(validator): skip required field checks… → failed: syntax error near unexpected token 'validator' — a commit message mislabeled as runnable shell.
• Challenge 2 setup sed -i '' 's/world/esteemed colleague/' greetings.txt → failed on GNU/Linux sed: sed: can't read s/world/…: No such file or directory (BSD/macOS-only syntax). Also git switch main fails because a bare git init (no init.defaultBranch=main) creates master — verified on the sandbox’s git 2.54. After fixing both, the conflict simulation reproduced exactly as described.
• Chapter 4 npx standard-version --dry-run / npx standard-version → failed: Invalid version. Must be a string. Got type "undefined" because the section never does git init / adds a version to package.json (unlike Challenges 2–3 which do).
• Chapter 5 conflict-resolution block (conflict markers mixed with real commands in one bash fence) → failed: syntax error near unexpected token '<<<' before reaching the real git add/git rebase --continue.
• gh api … branch protection and gh release create → skipped (no auth/remote); flags verified valid. Challenge 3 five-branch setup → passed once main was pre-configured.

3. Conquer King EDGAR — 80% (pass) · ran 6 / passed 6 / reasoned 3

• Linux venv + pip install requests pandas → passed (requests 2.34.2, pandas 3.0.3, Python 3.12.13).
• Level 001 get_submissions('320193') → passed, live data.sec.gov: Apple Inc. 1000. Level 002 → Accounts Payable, Current 2026-03-28 57349000000. Level 003 → saved apple_net_income.csv (334 rows). Level 004 → Points Foreseen: 3390. All real API data.
• Reasoned finding: the quest claims “Malformed CIKs → 400 errors” but live test returned 404 for both unpadded and non-numeric CIKs. Also HEADERS is reused in Levels 002/003/004 without redefinition → NameError if a learner pastes blocks into separate files.
• macOS/Windows setup blocks → reasoned (no such env in sandbox).

4. The Temple of Templates — 56% (fail) · ran 10 / passed 5 / failed 5 / skipped 2 / reasoned 3

• templates/base.html, page.html, partials/button.html, extended page.html as literally shown → failed: every block is wrapped in literal {​% raw %​}…{​% endraw %​} text (Jekyll/Liquid escaping that leaked into the published Markdown). Copy-pasted verbatim into render.py, they output literal {​% block title %​} text instead of the documented <h1>Hello Acolyte!</h1>. No exception is thrown → silent, confusing failure.
• After manually stripping the raw tags, render.py and the {​% include … with context %​} composition → passed (<button class="btn secondary">Click me</button>).
• C++20 concepts snippet g++ maxof.cpp -o maxof → failed: 'requires' does not name a type … only available with '-std=c++20'. Default GCC 13 mode is C++17; the quest never states the flag. Compiles/runs (7 2.5) only with -std=c++20.
• Card.jsx / Layout.jsx verified in a real Vite + Vitest project → passed (2/2 tests). The “Snapshot Test” block is commented-out pseudocode requiring unstated vitest/jsdom config.

5. ETL Pipeline Design — 68% (warn) · ran 6 / passed 5 / failed 1 / skipped 3 / reasoned 1

• extract() → passed, live jsonplaceholder.typicode.com/users: Extracted 10 records. transform() → passed, correct shape (ingested_at). load() + double-run idempotency → passed: SELECT COUNT(*) stayed at 10 across two full python etl.py invocations, no UNIQUE errors — idempotency genuinely demonstrated.
• SELECT COALESCE(MAX(updated_at), '1970-01-01') … FROM users; → failed: no such column: updated_at — the users table the quest itself builds only has ingested_at.
• Airflow DAG dags/users_etl.py → reasoned: py_compile clean; not run (heavy Airflow install). Noted the docker run apache/airflow:2.9.3 standalone command has no -v …/dags volume mount, so the DAG never appears in the UI the Advanced Challenge tells learners to check.
• pandas is installed in every setup path but never imported/used anywhere in the code.

🐞 Issues Found

Every issue below cites a command result or quoted line witnessed in this session. Grouped by severity.

HIGH

1. high · Temple of Templates · every Jinja code block (Ch.1–2) — Blocks contain literal {​% raw %​}…{​% endraw %​} escaping artifacts; copy-pasted verbatim they render literal template syntax instead of the documented output, with no error thrown. Fix: strip the {​% raw %​} wrappers from the published Markdown (this is a rendering-pipeline leak). (observed: render.py printed {​% extends 'base.html' %​} as text; passed only after stripping.)
2. high · ETL Pipeline Design · Ch.3 watermark SQL — SELECT … MAX(updated_at) … FROM users throws no such column: updated_at against the quest’s own warehouse.db. Fix: use ingested_at, or add/populate an updated_at column in the CREATE TABLE.
3. high · Mastering Version Control · Challenges 2 & 3 — sed -i '' … is BSD/macOS-only (fails on GNU/Linux); git init + git switch main fails where init.defaultBranch isn’t main (default master, verified git 2.54). Fix: use perl -pi -e or portable sed, and git init -b main (or set init.defaultBranch up front).
4. high · Mastering Version Control · Ch.4 standard-version block — npx standard-version --dry-run fails Invalid version. Must be a string. — no git init/version field setup. Fix: add the git init + versioned package.json preamble.
5. high · Warden Pact · Hands-On Lab Step 3 — Documented “Expected” line for edit-database-migration does not match actual output (script checks forbidden-paths before autonomy level). Fix: reorder warden.sh or update the Expected block to the real forbidden-path message.
6. high · Warden Pact · Ch.3 audit-trail heredoc — Emits multi-line JSON, not the single-line JSONL the prose claims/justifies. Fix: build the JSON on one line (jq -c or a shell var).

MEDIUM

1. medium · Mastering Version Control · Ch.1 — commit message fenced as ```bash → syntax error near unexpected token 'validator'. Fix: refence as text or prefix git commit -m.
2. medium · Mastering Version Control · Ch.5 — conflict markers + real commands in one bash fence → syntax error near unexpected token '<<<'. Fix: split “what you’ll see” (text) from “what you type” (bash).
3. medium · Mastering Version Control · Ch.6 — gh api … --field required_status_checks='{JSON}' sends a literal string, not a nested object (reasoned, per gh api --help). Fix: use --input or key[subkey]=value syntax.
4. medium · Temple of Templates · Ch.3 C++ — concepts example needs unstated -std=c++20 (fails on default C++17). Fix: state the flag + compiler-version requirement.
5. medium · Temple of Templates · React setup — only installs the CLI globally; never shows npm create vite@latest … --template react, and the snapshot test is commented-out pseudocode with no vitest/jsdom config. Fix: add the scaffold + minimal test config.
6. medium · ETL · docker/Airflow — docker run … standalone lacks a dags/ volume mount, so the DAG never appears in the UI the Advanced Challenge validates against. Fix: add -v $(pwd)/dags:/opt/airflow/dags.
7. medium · EDGAR · content accuracy — “Malformed CIKs → 400 errors” is wrong; live test returned 404. Fix: correct to 404.
8. medium · EDGAR · completeness — objectives “fetch ≥2 CIKs”, “compare ≥2 entities”, CSV export, and backoff-on-all-endpoints have no example code. Fix: add worked examples (name a peer CIK, e.g. Microsoft 789019).

LOW

1. low · ETL — pandas installed in every setup path but never used. Fix: use it or drop it.
2. low · EDGAR — HEADERS reused across Levels 002–004 without redefinition → NameError if pasted into separate files. Fix: note the blocks are one continuous session.
3. low · Temple of Templates — “Follow-Up Quests” lists a Level 1100 quest as a follow-up to this Level 1100 quest. Fix: point to a higher level.
4. low · Warden Pact — knowledge checks have no answer key. Fix: add collapsed self-check answers.
5. low · Mastering Version Control — standard-version (primary hands-on tool) last published 2023; unmaintained. Fix: flag it and prefer release-please/changesets.

🔗 Chain Continuity

This slice is a level band, not a dependency chain. Reading the five quests in plan order, they belong to five different quest series with no cross-quest prerequisites among them:

• The only real link in the window is ETL → EDGAR: etl-pipeline-design.md lists conquer-king-edgar as a recommended quest, and it’s a sensible ordering — EDGAR teaches “pull JSON from a live HTTP API into pandas/CSV,” which is exactly the extract() skill ETL assumes. A learner who did EDGAR first arrives at ETL’s extract() genuinely prepared. Good continuity there.
• For a Data Scientist specifically, the coherence is loose. EDGAR and ETL are on-theme (Data Engineering). The Warden Pact (agentic-AI/Copilot guardrails), Mastering Version Control (git/devops), and Temple of Templates (C++/Jinja/React abstractions) are cross-cutting engineering skills grouped by the 1100 level band, not a data-engineering throughline. That’s fine as a level — a Master data engineer does need git, templating, and agent governance — but a learner shouldn’t expect a narrative progression; each is a standalone module.
• Prerequisite realism: none of the five silently assumes state produced by an earlier quest in this window (they each set up their own sandbox), so there’s no broken hand-off between quests. The friction is within each quest (undefined HEADERS, missing git init, unstated -std=c++20), not between them. The updated_at bug in ETL and the raw-tag leak in Temple are the two places a diligent learner is most likely to abandon the quest.
• Ordering observation: difficulty ordering in the window is uneven (Hard, Hard, Medium, Medium, Hard). The two Medium quests (EDGAR at 80, Temple at 56) sit in the middle; a learner hitting Temple’s silent Jinja failure right after the confidence-building EDGAR success would be especially confused.

🧠 Reasoning & Method

• Mode: execute — the workflow pre-computed and sealed walk-evidence.json / walk-evidence.md by running test/quest-validator/agentic_validate.py --mode execute in a disposable sandbox before I ran. I consumed that evidence as-is and did not re-run the engine (its child claude processes can’t authenticate from my Bash tool) and did not edit the plan or evidence. Every passed/failed above is an engine-run command; everything I marked reasoned was judged statically by the engine (no macOS/Windows env, no gh auth, no heavy Airflow install).
• What I ran vs. reasoned: I did not execute quest commands myself — the sealed engine did. My contribution is the linked-journey pass (§6): I read all five quest sources in plan order and their frontmatter prerequisites/series to judge continuity, and I cross-referenced every issue in §5 against a witnessed command result or a quoted quest line.
• Coverage & limits (honest): This is window 1 of 3 — 5 of the 15 quests in the full Level-1100 slice (stats.total_quests: 15). The remaining 10 quests are not covered here and should be swept in later runs before the level is certified. Skipped/reasoned areas: macOS/Windows setup paths (no such env), gh api/gh release branch-protection (no auth/remote), and the Airflow standalone container (heavy install / long-running server). Engine cost ~$4.52, avg 68.8%.
• Confidence: High on the executed findings (real commands, real output quoted). Medium on the reasoned items explicitly labeled as such (e.g. gh api --field nesting, workflow_run.workflows glob support, GitHub workflow_run wildcard behavior) — the engine flagged these as offline-unverifiable, and I’ve preserved that caveat rather than asserting them as certain.

No content was modified. This is a read-only witness report; a content-curator or human should act on §5.