Editing This founder built a $15k MRR SaaS in 12 hours

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As an AI enthusiast and solo hacker myself, I have recently been digging into the stories of successful solo indie hackers.

It gives me great pleasure to write about people who have persevered and emerged at the other end.

One such founder is Louis, who turned a bold weekend experiment into a growing SaaS. What stands out is how he approached building, validating, and monetizing with a lean, repeatable process. Here’s what I learned from his journey.

About the Founder
Louis is from India and has been juggling a full-time role with his family business on the offline side of things. He started exploring the no-code space back in 2015 when the tools were still early and limited. In 2021, while working with the family business, he reconnected with the internet world and discovered Bubble. He built a string of small tools — perhaps 15 to 20 — most of which didn’t take off, but Audio Pen did. Audio Pen became the first tool in his run that reached a meaningful revenue level, giving him a reliable secondary income.

His approach traces back to a habit he formed in 2022: a hackathon-like event called Halfday Build, run in the “build in public” spirit. On Sundays, participants would aim to move from idea to MVP to revenue within 12 hours, starting at noon and aiming for a dollar by midnight. Louis started small, building a handful of tools on his personal site, and Audio Pen emerged from that effort. After sharing progress publicly, the product resonated with people, and early testers even paid for the product before it was fully polished. He emphasizes that much of success comes from experimentation with low costs and from being visible — building in public and engaging with a supportive community.

When it came to scale, the app now claims about 200,000 users and more than 5,000 paying customers. The pricing model includes a free tier and paid versions at $99 per year or $159 for two years, both described as non-recurring subscriptions that users can renew at the end of their term.

The core idea behind Audio Pen is simple: it’s a voice-to-text tool that adapts to a writing style of your choice, with transcription feeding into a writing process across languages, on both mobile and desktop.

Louis attributes part of the early signal to his credibility on Twitter, built by consistently sharing progress and outcomes from building in public. He also notes that the design matters: a thoughtful pre-launch design phase helped him communicate what the product would do and why it mattered. The takeaway is clear — credibility, clear design, and a willingness to test ideas openly can create momentum that compounds quickly, even for solo founders.

If I were to summarize his mindset: start small, design before you build, share early, and take early revenue signals seriously while you iterate toward a focused, well-executed core capability.

Tech stack and tools Used
Louis is open about the tools and platforms he used to ship Audio Pen and manage ongoing operations. Here’s a snapshot of the tech stack and related tools he mentioned:

* 		Bubble — used for building the web app (no-code platform)
* 		Zeno — backend and logic layer
* 		Draft Bit — for building native apps
* 		Loops — email platform
* 		Pausible Analytics — analytics
* 		Stripe — payments and early revenue signals
* 		Pinterest — used for design inspiration
* 		X — platform for building in public and signal validation
Final piece of advice
From Louis’s journey, one core insight stands out: embrace experimentation and modular growth. His guidance boils down to four actionable steps:
* 		Build many small things for fun to learn quickly and reduce risk.
* 		Design before you build to ensure you know what you’re aiming for and to differentiate your product.
* 		Build in public and invite feedback early, then use those signals to decide what to double down on.
* 		Launch the simplest version that gets the job done, then iterate and raise the price as you refine the product.
He also emphasizes staying human and authentic as an indie founder: people appreciate seeing a real journey, not a polished corporate persona. When something resonates with users, double down on it, and let your failures teach you about what works.

Conclusion
If you’re looking to replicate this approach, start by sketching your core problem, gathering early feedback, and aiming to ship a minimal, usable version quickly. Let the market tell you what to invest in next, and keep the loop tight between building, testing, and refining.

References
* 		Twitter contact: https://x.com/louispereira
* 		AudioPen: https://audiopen.ai
* 		YouTube interview: https://www.youtube.com/watch?v=k2jecxFu2as

Read the full article here: https://medium.com/@AIBites/this-founder-built-a-15k-mrr-saas-in-12-hours-82dd65e0be0a