Summary
Brian Casel, developer and creator behind Builder Methods, walks through building a complete time tracking and invoicing application from scratch using Claude Code — targeting freelancers, consultants, and hourly billers who want a custom tool that fits their exact workflow rather than an overpriced SaaS product.
The video showcases Casel’s full methodology rather than just the coding: it begins with a high-level requirements brain dump, then runs a custom “PRD creator” skill inside Claude Code to generate a structured Product Requirements Document, breaks the project into four discrete milestones, and uses Claude Code’s Plan Mode to produce a detailed implementation roadmap before a single line of code is written. He works inside a multi-project environment called Superconductor alongside a personal application template called “Build New,” which ships with a pre-built design system. Each milestone gets its own prompt.md file that can be dragged directly into Claude Code, and the agent writes a running milestone-log.md as it builds — giving developers a live record of progress and decisions.
The video emphasizes transferable process over specific syntax: the same PRD-first, milestone-by-milestone approach applies regardless of what you’re building. Viewers will come away understanding how to structure requirements for Claude Code, when to use Plan Mode for more accurate and self-correcting output, and how to keep a living codebase-embedded spec that the AI can reference and update throughout the project. The result is a working time biller app with client management, timer functionality, manual time entry, and automated invoice generation.
📺 Source: Brian Casel · Published June 29, 2026
🏷️ Format: Hands On Build
