Comment by robeym

I built an ERP system called PAX ERP mostly solo for small manufacturers in the USA.

Stack is React, Express, PostgreSQL, all on AWS with a React build pipeline through GitHub Actions. It handles inventory, work orders (MRP), purchasing, GAAP accounting, email campaigns, CRM, shipping (FDX or UPS), etc.

AI has been useful (I use Claude Code, mainly Haiku model), but only if I'm steering it carefully and reviewing everything. It is obviously not great at system design, so I still need to know exactly what I'm trying to do. If I don't it'll often make things overly complicated or focus on edge cases that don't really exist.

It helps a lot with: Writing/refactoring SQL, Making new API routes based on my CRUD template, Creating new frontend components from specs and existing templates, Debugging and explaining unexpected behavior, Integrating third-party APIs (Fedex for shipping, Resend for emails). It understands their documentation easily and helps connect the pieces.

In practice, it feels like a fancy copy/paste (new routes, components) or a helpful assistant. With careful guidance and review, it's a real efficiency boost, especially solo.