What happens when a vibe-coded app gets 1,000 users?

I recently launched my app and I’m currently around 400 users. That sounded like a small number when I was building it, but now that people are actually using it, I’m starting to experience problems I honestly didn’t think much about when I started.

I’ve had some failures and breakages involving AWS and Vercel, and it got me thinking about something I probably should have considered earlier:

What happens when this thing gets to 1,000 users?

Right now, Vercel seems to be working fine for the most part, but after experiencing a few issues, I’ve started looking at Netlify as another option. And now I’m stuck between whether I should migrate while the app is still relatively small or just leave everything alone and deal with it when there is actually a problem.

The bigger concern is the cost.

I’m not a big-money founder with a huge runway. Most of my users are using the product for free, and I’m still waiting for an ad network (Google Adsense) to approve the site so I can start generating some revenue.

The site has also started picking up, so I’m trying to think ahead instead of waiting until something completely breaks.

If I get to 1,000 users, I’m estimating that could mean at least 10,000 pageviews, potentially more depending on how active those users become.

Then there’s Supabase. If usage keeps growing, I may need to upgrade there too. Then there’s Vercel or Netlify, AWS, database costs, storage, bandwidth, etc.

Suddenly, a product that costs almost nothing to build with AI can start becoming a completely different financial problem once real people start using it. That’s the part nobody really talks about when they say AI has made building startups easy.

Building the first version is easy.
Keeping it running when people actually depend on it is a different story.
So I’d genuinely like to hear from founders who have gone through this already.

If you’ve built a vibe-coded app or SaaS and grown from a few hundred users to 1,000+, how did your infrastructure hold up?

Would you recommend staying with Vercel, moving to Netlify, or is the platform choice not really the problem at this stage? And if you were in my position, would you migrate now while the app is still around 400 users, or keep building and only change infrastructure when there is a clear need?

I’m especially interested in hearing from founders who bootstrapped their product and had to keep infrastructure costs extremely low while the majority of users were still free.

I’d rather learn from someone who has already hit this wall than spend money solving a problem I might not actually have yet.