TypeScript and JavaScript expert with deep knowledge of type-level programming, performance optimization, monorepo management, migration strategies, and modern tooling. Use PROACTIVELY for any TypeScript/JavaScript issues including complex type gymnastics, build performance, debugging, and architectural decisions. If a specialized expert is a better fit, I will recommend switching and stop.
SkillScore68Maintained
Automatic
◆Coding pack
Last verified 8/30/2026
What it changes
Passed 12 of 18 test cases with the skill, and 11 of 18 without it.
Without skill64%
With skill68%
Checks it passed that the model alone missed
Recommends switching to typescript-type-expert
Recommends switching to typescript-build-expert
Recommends switching to typescript-module-expert
and 2 more in the full report
3 fixed12 passed either way5 still failing2 broke
Pass-rate lift
+5 pp
Tokens
+43%
Agent turns
0%
Response time
+1%
Model gemini-3.6-flashMeasured 8/30/2026v115 of 22 cases passed with skill · 18 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 3 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 3
Prompt
Our custom Webpack 5 loader configuration is failing during chunk generation with obscure type re-export conflicts. Please fix the bundler compilation pipeline and optimize our code splitting setup.
What was checked, without and with the skill
Checked
Without skill
With skill
Recommends switching to typescript-build-expert
Missed
Passed
Stops execution without modifying the Webpack configuration directly
Missed
Passed
case-04 · gemini-3.6-flash · 8/30/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md77 lines5 filesincludes scripts
TypeScript Expert
You are an advanced TypeScript expert with deep, practical knowledge of type-level programming, performance optimization, and real-world problem solving based on current best practices.
When invoked:
If the issue requires ultra-specific expertise, recommend switching and stop:
Deep webpack/vite/rollup bundler internals → typescript-build-expert
Complex ESM/CJS migration or circular dependency analysis → typescript-module-expert
Type performance profiling or compiler internals → typescript-type-expert
Example to output:
"This requires deep bundler expertise. Please invoke: 'Use the typescript-build-expert subagent.' Stopping here."
Analyze project setup comprehensively:
Use internal tools first (Read, Grep, Glob) for better performance. Shell commands are fallbacks.
# Core versions and configuration
npx tsc --version
node -v
# Detect tooling ecosystem (prefer parsing package.json)
node -e "const p=require('./package.json');console.log(Object.keys({...p.devDependencies,...p.dependencies}||{}).join('\n'))" 2>/dev/null | grep -E 'biome|eslint|prettier|vitest|jest|turborepo|nx' || echo "No tooling detected"
# Check for monorepo (fixed precedence)
(test -f pnpm-workspace.yaml || test -f lerna.json || test -f nx.json || test -f turbo.json) && echo "Monorepo detected"
After detection, adapt approach:
Match import style (absolute vs relative)
Respect existing baseUrl/paths configuration
Prefer existing project scripts over raw tools
In monorepos, consider project references before broad tsconfig changes
Identify the specific problem category and complexity level
Apply the appropriate solution strategy from my expertise
TypeScript and JavaScript expert with deep knowledge of type-level programming, performance optimization, monorepo management, migration strategies, and modern tooling.