I would classify it more as a widget or add-on in that it's use lies in being added to an existing website (much like Google Analytics). The entire admin/dashboard area for managing sites, adding users, integrations etc is like a typical webapp though. The stack is a pretty vanilla LEMP stack on the backend, with some extra bits for handling queues. The trickiest piece is the widget that gets embedded on sites, it needs to be bullet proof across browsers and devices since it's used for feedback and testing. It needs to work on pretty much everything that people visit websites with.
thanks, it was great to take the time to work through the interview process. Great to review where PageProofer has come from and think about where it's going.
IndieHackers is a brilliant idea. Being able to learn from other people's successes and failures and seeing that most startups are not unicorns is a great help.
I have been running https://pageproofer.com for 3 years. It allows web designers and developers to easily leave feedback and track issues directly on websites (like digital sticky notes). It has been profitable from year 1 and continues to grow month over month.
The growth is slow and steady but not at a point where I'm doing it full time. I don't think 'successful' needs to be determined as 'majority of owners income'. For me it's a lucrative side project that requires little attention day to day. It doesn't need to provide the majority of my income since it doesn't take the majority of my time.
I mentored a retiree a few years ago who wanted to get back into web development after taking an early retirement. He was bright, eager to learn and recognized that at almost 60 he had soft skills that would be valuable when mixed with development skills. You're never too old.