How a hobby landed me an acquisition

Feb 7, 2025

Side-projects are not just hobbies.

My ‘hobby’ landed me a call with the CEO of Calm, an acquisition, and a $40M startup.

I’ve meditated for 15+ years and kept a meditation journal from day one. I knew the value of keeping a journal, but reading others’ was just as powerful.

So, I created a social network for meditators to share their journals and follow each other. I called it OpenSit.

It never made any money and I never tried to charge. It was open source, so whilst I was the lead engineer, members also contributed their own fixes and features.

I learned a lot doing everything myself:

How to build a community from scratch
How to balance technical work with design and marketing
How to focus on the highest-impact work in my limited time.

One day, I woke up to an email from Alex Tew, CEO of the now $2b Calm. He told me he liked OpenSit. I was flabbergasted that he was even aware of it, but we had a nice chat and stayed in touch.

A year later, Calm had a job opening, and I got an invite from Alex to apply. It didn’t work out in the end (see: Ruby developer applies for Javascript job) but it was a great opportuntity that I would have missed otherwise.

One day, someone emailed me out of the blue with a feature idea for OpenSit. We had some calls and stayed in contact.

A year later, this person came back with funding. They were looking to launch an app for the US market that offered pain relief via mindfulness. OpenSit was a solid base to build on and they wanted to acquire it.

And they did. It wasn’t life-changing money, but it was a significant outcome for something that was just a free side project. I went to work with the new team as CTO and we got to partner with one of the UK’s leading mindfulness research centres.

One day, whilst doing in-person user research at that centre, I met a new consultant brought in to assist us with research.

A year later, this person was starting a new venture and asked me if I wanted to join as a cofounder. I said yes, and we went on to raise over $40m.

Side-projects are not just hobbies. Build something, share it and stick with it—you have no idea what doors it might open up.

—Dan