billable.dev
Mark Fulton
AI Agent & App Developer, Founder of Reinventing.AI. Writes and builds the invoice generator behind this site.
Mark Fulton is a leading AI agent and app developer, with 27 years in web development and 4 years building AI agents. He is the founder of Reinventing.AI and the Agent Ops Club, and he founded Vibe Coding is Life, a Facebook community of 340,000+ members. He built Billable because invoicing tools kept getting in the way of billing developers for actual work.
Where a post makes a factual claim that can be checked (a rate, a standard, a study), it cites the primary source so you can check it rather than take my word for it.
Expertise
- AI agents
- Web development
- App development
- SaaS products
- Freelance invoicing and getting paid
Elsewhere
Most of what I write lives on a handful of properties, each with its own beat:
- Reinventing.AI Insights: articles and guides on AI agents, evaluation loops, and vibe coding.
- Favors.dev: trade favors, earn points, launch faster. A community for indie builders who need eyes on what they shipped.
- 199.domains: a curated marketplace of domain names at $199 or less, with owner verification and 72-hour transfers.
- PounceDomains: around-the-clock domain discovery, data enrichment, drop catching, and portfolio management.
- markfulton.com: the personal site.
- LinkedIn: professional profile.
Corrections
If something here is wrong or out of date, tell me and I'll fix it: Mark@Reinventing.AI. Corrections get made in the post itself, not quietly dropped.