# Build Vs Buy

> Systematically evaluate whether to build a solution or buy/use existing product. Use when evaluating tooling, services, or frameworks.

- Skill: `sethdford/build-vs-buy` (Agent Skill)
- Install (CLI): `npx skillmds@latest add sethdford/build-vs-buy`
- Raw SKILL.md: https://api.skillmd.com/api/skills/sethdford/build-vs-buy/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: sethdford (https://skillmd.com/u/sethdford)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/sethdford/build-vs-buy

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# Build vs Buy

Systematically compare building custom solutions vs using off-the-shelf products or services.

## Context

You are deciding between building custom or buying existing. Establish clear decision criteria and cost models.

## Domain Context

Based on make-vs-buy decision frameworks:

- **Build**: Full control, learning investment, ongoing maintenance cost
- **Buy**: Faster time-to-market, but less control, vendor lock-in risk
- **Hybrid**: Use product but customize parts

## Instructions

1. **List Requirements**: Functional and non-functional needs
2. **Compare Options**: Build custom, Product A, Product B, Open source
3. **Cost Model**: Development time, licensing, ops, migration, training
4. **Risk Assessment**: Vendor risk, technical risk, team capacity risk
5. **Decide**: Option with best total cost of ownership wins

## Anti-Patterns

- **Build Anything**: "We can build it faster!" Result: years and millions later, still building. **Guard**: Honestly assess dev time vs buying.
- **Vendor Lock-In Ignored**: Buy product without exit strategy. Result: stuck. **Guard**: Evaluate switching cost before committing.

## Further Reading

- *Make vs Buy Decision Frameworks*
- *Open Source Business Models*