I’m not aware of any huge successes in SaaS that were active side projects while the founders worked at different companies.
But there are a bunch that were side projects at the same company:
- Mailchimp was a side project while the founders ran a web-design agency. There are many start-ups born out of agenies and consultancies. It can be a tough transition, but it’s pretty common.
- Hootsuite was also a web-agency spin-off.
- Slack was an internal tool built when the company was a gaming company. It took off.
Mailchimp is perhaps the most interesting one to me because they took their time until 2007 to go all-in. But once they did, growth accelerated. Dramatically.
