Building an AI tool in a half-day hackathon and hitting $20k/mo

Louis Pereira built an AI tool called AudioPen in a half-day hackathon and grew it to ~$20k/mo within two years.

Here's Louis on how he did it. 👇

A non-technical indie hacker

I don't have a technical background, but I love building stuff — and the internet is the most friction-free place to build. Honestly, I would build tools online even if I didn't make money doing it. I did it for years before any major success, and I'll continue doing it for as long as I can.

Currently, I'm working on AudioPen, which I've been growing for the last two years. It's a voice-to-text AI tool that makes it easy to go from fuzzy thought to clear text.

I charge a subscription fee, and only offer annual and two-year options. It currently generates between $15k and $20k per month.

Starting with a hackathon

I built AudioPen during Half Day Build, a hackathon I organized a couple of years ago.

I had already released it as a small tool on my website by that point. People loved it, so I decided to build it as a full-blown, independent product during the hackathon. And here we are.

I use Bubble for the web app and Draftbit for the mobile apps. I also use Xano for a common back end.

Overcoming DDoS attacks

At one point, I started receiving random DDoS attacks from unfamiliar parts of the world. These attacks temporarily brought down the site. Some even marked the site as spam for many email providers.

Responding to each person and restoring normal operations took a huge amount of effort.

I don't think I would have done anything differently, though — I don't think it could have been avoided. It's the nature of the game we play online. I wish it hadn't happened, but it did, and I'm glad it's over.

Hopefully, it doesn't happen again.

Social media and word of mouth

Initially, I used Twitter extensively, tweeting about my product often. Being active in the Twitter community was very helpful back in 2023 when I built AudioPen.

I'm unsure if this holds true today because the algorithm has changed, but I'm sure there are pockets of the internet where one can follow a similar strategy.

Once the product gained a certain number of users, word of mouth took over. That's how I currently get most of my users. And I'm looking into other channels.

You will strike gold

Here's my advice: Just keep building.

It's never been easier to experiment and create new things on the internet. If you genuinely like to do it, make as much time as you can to focus on creating stuff that's useful for others.

Eventually, you will strike gold.

What's next?

I want to grow AudioPen as much as I can. For the next year, I want to at least 10x its revenue.

You can go to AudioPen.ai for the product, and I'm @louispereira on X.