I've been building Zigpoll [1] over the past 4-5 years as a solo project. It's a micro survey platform (Saas) that can live on any website and can be triggered at key moments during your customer journey. I found a niche in post-purchase surveys for Shopify which helped get me over the 2K mark and build a meaningful customer feedback loop I could iterate on to find a tighter product market fit (very meta for a survey platform I know). This took about three years to hit and it helped greatly to be on an app store since it's a full service marketing channel which 1. is my weakest skillset and 2. you want all the leverage you can get if it's a part time project.

The post purchase survey angle is growing steadily but the platform was built to be flexible so I'm looking for other use-cases to focus on what competitors don't currently service for a phase 2.

Also recently it's been a great way to experiment with OpenAI and see what all the buzz is about. So far the ChatGPT API has been very impressive at spotting trends in user-provided data to share with our customers. Honestly this feature alone makes me consider focusing on it full time; but it would be a bit of a leap financially given current circumstances.

TLDR: I recommend building something, keeping your head on a swivel, getting feedback (being on an app store or marketplace makes this easier) and adjusting as rapidly as possible if you want to get paid and have a shot at bootstrapping bigger.

[1] https://www.zigpoll.com