What are Claude Code Skills?

Claude Code Skills are reusable prompt templates stored as markdown files in your project's .claude/skills/ directory. They let you codify best practices and common workflows into slash commands that Claude follows consistently.

How do I create a Claude Code Skill?

Create a markdown file in .claude/skills/ with instructions for Claude. The filename becomes the command name — for example, .claude/skills/code-review.md can be invoked with /code-review during a Claude Code session.

Can I share skills with my team?

Yes. Skills stored in .claude/skills/ can be committed to version control so every team member has access to the same standardized workflows. You can also organize skills into subdirectories by category.

What is the difference between project and global skills?

Project skills (.claude/skills/) are specific to the current project and are committed to git. Global skills (~/.claude/skills/) are personal skills available across all your projects.

billy-milligan

New

13Community RegistryGeneralby Raman Navarych

5 toxic senior engineers trapped in one plugin. They argue, roast each other, call you a meat bag, and somehow deliver excellent technical decisions. Multiplied personality disorder as a development methodology.

Community PluginView Source

Overview

bash

claude plugin marketplace add rnavarych/alpha-engineer

Alpha-Engineer: Claude Code Plugin Marketplace

24 agents. 191 skills. 22 commands. Specialized engineering plugins for Claude Code across 9 developer roles, 4 industry domains, and one unhinged team of 5 senior engineers.

Billy Milligan — The Team Inside Your Head

5 senior engineers trapped in one plugin. They deliver excellent technical decisions. Multiplied personality disorder as a development methodology.

bash

claude plugin install billy-milligan@alpha-engineer

Control the Billy Milligan experience.

code

/billy off     → Professional mode (for client demos)
/billy on      → Bring the idiots back
/billy status  → Show current state

Agent	Role	Style
Viktor	Senior Architect	Draws boxes, quotes Fowler, never writes code
Max	Senior Tech Lead	Ships it, asks questions later
Dennis	Senior Fullstack Dev	Grumpy, writes the actual code
Sasha	Senior AQA Engineer	Paranoid, everything will break
Lena	Senior Business Analyst	Sharpest person in the room

[Read the full Billy Milligan documentation](plugins/billy-milligan/README.md) — commands, memory system, team dynamics, relationship map, and running jokes.

What's Inside

Category	Plugins	Agents	Skills	Commands
Foundation	1 (alpha-core)	2	11	--
Roles	9	9	96	--
Domains	4	8	32	--
Billy Milligan	1	5	52	22
Total	15	24	191	22

Developer Roles

•Senior Frontend Developer — React, Vue, Angular, CSS, accessibility, performance
•Senior Backend Developer — APIs, databases, microservices, message queues
•Senior Mobile Developer — React Native, Flutter, iOS, Android
•Senior DevOps Engineer — Docker, Kubernetes, Terraform, CI/CD, monitoring, AWS, Azure, GCP
•Senior AQA Engineer — Test strategy, E2E, API, performance, security testing
•Senior Architect — System design, ADRs, scalability, tech stack, AWS/Azure/GCP architecture
•Senior Fullstack Engineer — End-to-end development, scaffolding, deployment
•Senior Algorithms Engineer — Algorithm design, data structures, dynamic programming, graph algorithms, optimization
•Senior Database Engineer — 230+ databases across 14 categories, schema design, query optimization, replication, backup/recovery, migrations

Industry Domains

•IoT — MQTT, device management, edge computing, time-series data
•E-Commerce — Payments, catalogs, checkout, inventory, PCI compliance
•Fintech — Ledger design, transactions, regulatory compliance, fraud detection
•HealthCare — HIPAA, HL7 FHIR, PHI handling, EHR integration, telehealth

Cross-Cutting Foundation

•Database advisor (SQL, NoSQL, Graph, Columnar, Key-Value, Time Series)
•Security advisor (OWASP, auth, encryption)
•API design (REST, GraphQL, gRPC, WebSocket)
•Architecture patterns (SOLID, DDD, CQRS, microservices)
•Testing patterns, Performance optimization, CI/CD, Observability, Cloud infrastructure
•AI/ML engineering (system design, SaaS platforms, MLOps)
•Code review, Legal compliance reviews

Installation

Install the entire marketplace

bash

claude plugin marketplace add rnavarych/alpha-engineer

Install individual plugins

bash

claude plugin install alpha-core@alpha-engineer
claude plugin install role-backend@alpha-engineer
claude plugin install domain-fintech@alpha-engineer
claude plugin install billy-milligan@alpha-engineer

Recommended combinations

bash

# Backend developer working on fintech
claude plugin install alpha-core@alpha-engineer
claude plugin install role-backend@alpha-engineer
claude plugin install domain-fintech@alpha-engineer

# Frontend developer working on e-commerce
claude plugin install alpha-core@alpha-engineer
claude plugin install role-frontend@alpha-engineer
claude plugin install domain-ecommerce@alpha-engineer

# DevOps engineer for IoT platform
claude plugin install alpha-core@alpha-engineer
claude plugin install role-devops@alpha-engineer
claude plugin install domain-iot@alpha-engineer

# Any role + Billy Milligan (adds team dynamics to any setup)
claude plugin install billy-milligan@alpha-engineer

Usage

Invoke skills directly

code

/alpha-core:database-advisor
/role-backend:microservices
/domain-fintech:ledger-design

Billy Milligan commands

code

/billy:plan add user authentication
/billy:debate Redis vs PostgreSQL for caching
/billy:review src/components/Auth.tsx
/billy:roast should we use GraphQL?
/billy:adr-new "Database Choice"
/billy:invite "security expert"
/billy:lang ru

Invoke agents directly

code

# Role agents
/role-backend:senior-backend-developer design a REST API for user management

Agents activate automatically

Claude will delegate to the appropriate agent based on your task context. For example, asking about API design while role-backend is installed will activate the Senior Backend Developer agent.

Architecture

code

alpha-core (foundation) ──┐
                          ├── Combined by Claude at runtime
role-<name> (persona)  ───┤
                          │
domain-<name> (domain) ───┤
                          │
billy-milligan (team)  ───┘

Each layer is independent and composable. Install only what you need.

Plugin Catalog

Plugin	Category	Agents	Skills	Description
`alpha-core`	foundation	2	11	Cross-cutting engineering skills
`role-frontend`	role	1	8	React, Vue, Angular, CSS, a11y, performance
`role-backend`	role	1	8	APIs, databases, microservices, queues
`role-mobile`	role	1	8	React Native, Flutter, iOS, Android
`role-devops`	role	1	11	Docker, K8s, Terraform, AWS, Azure, GCP
`role-aqa`	role	1	8	Test strategy, E2E, API, load, security
`role-architect`	role	1	11	System design, ADRs, AWS/Azure/GCP architecture
`role-fullstack`	role	1	8	End-to-end development, scaffolding
`role-algorithms`	role	1	8	Algorithms, data structures, optimization
`role-database`	role	1	26	230+ databases, schema design, query optimization, DBA lifecycle
`domain-iot`	domain	2	8	MQTT, edge computing, device management
`domain-ecommerce`	domain	2	8	Payments, catalogs, checkout, inventory
`domain-fintech`	domain	2	8	Ledger design, transactions, compliance
`domain-healthcare`	domain	2	8	HIPAA, HL7 FHIR, PHI, EHR, telehealth
`billy-milligan`	team	5	52	5 toxic engineers, 22 commands, dual memory

License

MIT

Install & Usage

Create the skills directory

mkdir -p .claude/skills

Download the skill file

mkdir -p .claude/skills && curl -o .claude/skills/billy-milligan.md https://raw.githubusercontent.com/rnavarych/alpha-engineer/main/SKILL.md

Invoke in Claude Code

/billy-milligan

View source on GitHub

pluginteamagentsarchitecttech-leadfullstackaqabusiness-analyst

Frequently Asked Questions

What is billy-milligan?

How to install billy-milligan?

To install billy-milligan, create the .claude/skills directory in your project, then run the curl command to download the skill file. Once installed, invoke it in Claude Code with /billy-milligan.

What is billy-milligan best for?

billy-milligan is a community categorized under General. It is designed for: plugin, team, agents, architect, tech-lead, fullstack, aqa, business-analyst. Created by Raman Navarych.