I'm a solo founder building culta.ai - a financial management platform that helps early-stage founders track budgets, burn rate, and cash flow without needing an accountant.
Here's a quick look at the stack and a few things I learned along the way.
The Stack
- Next.js 15 (App Router) + React 19
- Prisma + PostgreSQL
- Stripe for billing and Connect
- NextAuth for authentication
- Tailwind CSS for styling
- Deployed on Railway
Multi-Entity Architecture
One thing I needed early was support for multiple businesses per user. A freelancer might have a consultancy and a side project, they shouldn't need two accounts.
Every dashboard query is scoped to the selected entity using a React context provider. Switching between businesses is instant, no page reload.
Free Financial Calculators as a Growth Channel
Instead of just blogging, I built 17 interactive calculators - burn rate, runway, SaaS pricing, unit
economics, and more. Each one is its own page, targets a specific keyword, and funnels users toward signing up.
This has been a way more effective growth strategy than generic content marketing.
Lessons Learned
- Start with the data model. Getting multi-entity right early saved me from a painful refactor later.
- Calculators > blog posts for a financial tool. People searching "burn rate calculator" have higher intent than people reading "what is burn rate."
- Next.js App Router is great once you get past the learning curve. Server components made the dashboard noticeably faster.
Check It Out
If you're an early-stage founder trying to get a handle on your finances, give it a try:
https://culta.ai
Happy to answer any questions about the architecture or growth strategy.
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