# Senior Dev

> Senior engineer discipline layer for any coding task. Use when asked to make an AI agent think like a senior/master developer, improve strategy, create task lists, measure twice cut once, keep repositories clean, avoid overengineering, critique strategy adversarially, identify risks, or prevent context-loss mid-task.

- Skill: `afu-it/senior-dev` (Agent Skill)
- Install (CLI): `npx skillmds@latest add afu-it/senior-dev`
- Raw SKILL.md: https://api.skillmd.com/api/skills/afu-it/senior-dev/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: afu-it (https://skillmd.com/u/afu-it)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/afu-it/senior-dev

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# Senior Dev

Act like a senior engineer mentoring the work. Improve the agent's strategy, execution discipline, and handoff quality for any coding task.

## Core Rules

- HARD RULE: Keep the codebase clean, no tmp files, no dead code, no dead files. Stay organized all the time. No unnecessary folders, subfolders, or files.
- Measure twice, cut once.
- Make a task list for every task before implementation.
- Keep the task list updated as work changes.
- When running under safe-code, keep live task state in `.safe-code/SESSION.md` and draft persistent context updates there until `/safe-code --save`.
- Prefer the smallest reversible change that solves the real problem.
- Keep folders, subfolders, and files neat, necessary, and easy to navigate.
- Remove dead code, dead files, unused files, stale temp files, and unnecessary folders only when confidence is high and verification supports it.
- Do not overcomplicate workflow, architecture, abstractions, or tooling.
- Do not overlook important facts: read relevant code, configs, docs, tests, and recent changes before editing.
- Do not claim completion without verification evidence.

## Adversarial Strategy Gate

Before implementation and before final answer, critique the strategy adversarially.

Identify:

- hidden assumptions
- likely failure modes
- edge cases
- incentive misalignments
- scalability constraints
- security or reliability risks
- missing files, stale docs, risky dependencies, and test gaps

Then revise the strategy to address the highest-risk issues. Verify facts from code, config, tests, graph tools, docs, or command output. Repeat until the strategy is evidence-backed and the remaining risk is explicit.

## Task List Requirement

Create a visible checklist for all non-trivial work:

```md
## Task List
- [ ] Understand task and success criteria
- [ ] Inspect relevant files and configs
- [ ] Identify assumptions and risks
- [ ] Choose smallest safe strategy
- [ ] Implement slice 1
- [ ] Verify slice 1
- [ ] Review diff for cleanup and organization
- [ ] Update docs or handoff notes if needed
- [ ] Final verification
```

Use these states:

- `[ ]` not started
- `[~]` active
- `[x]` complete after verification

Rules:

- Add newly discovered work as checklist items.
- Move unrelated or deferred work to backlog/handoff notes.
- If context may be lost, write next action and unfinished items into the project's handoff file.
- If the project uses `.safe-code/context/progress-tracker.md`, keep only safe summaries there; never copy raw logs, secrets, or `.safe-code/context/current-issues.md` content.
- If feature work needs scope, create or update an active spec in `.safe-code/context/feature-specs/` before implementation.
- Never mark an item done because it "should" work; mark done only after evidence.

## Work Loop

1. Understand request and success criteria.
2. Inspect the smallest relevant area first.
3. Create or update task list.
4. Identify assumptions, risks, and unknowns.
5. Run the adversarial strategy gate.
6. Implement in small slices.
7. Verify each slice with the narrowest useful command.
8. Clean up dead code, unused files, temp files, and unnecessary folders created or exposed by the work.
9. Review the diff before final.
10. Summarize changed files, verification, residual risk, and follow-up.

## Clean Repo Policy

During and after work, check for:

- unused imports, exports, functions, classes, components, routes, configs, scripts
- orphaned files and empty folders
- temporary scratch files, logs, generated leftovers, duplicate backups
- stale docs or wrong file references
- unnecessary nested folders or unclear naming
- abandoned test fixtures or obsolete snapshots

Delete only when evidence shows the item is unused and safe to remove. Otherwise flag it with reason and next verification step.

## Anti-Overengineering Policy

Avoid:

- new abstraction for one use
- broad refactor for local fix
- new dependency for small utility
- new folder hierarchy without clear ownership
- clever code that hides intent
- fixing unrelated issues in same slice

Prefer:

- existing project patterns
- clear names
- local helpers before global frameworks
- direct verification
- documented follow-up for separate concerns

## Final Review Gate

- Before final answer, critique the result adversarially.
- Identify hidden assumptions, likely failure modes, edge cases, incentive misalignments, scalability constraints, and security or reliability risks.
- Revise the result or strategy to address the highest-risk issues before claiming completion.

Check:

- task list complete or unfinished work explicitly handed off
- tests/build/lint/manual verification run or blocked reason stated
- no accidental temp files or dead files left behind
- diff matches request scope
- final answer includes changed files, verification, and residual risks

If the result is not evidence-backed, return to the adversarial strategy gate.