What's one thing you did wrong while building your product?

That was for my previous startup. We built it based on our perspectives instead of conducting a proper market research and validating our customers needs

I've been putting it off for too long 🙃

Not doing a UX strategy, including the validating research. A need may be perceived, but is the prospect willing to pay for it? Are you positioning the product properly? The problem you "think" you're solving may not be the prospects problem. Tied into this is working hard to avoid stakeholder bias. I've seen stakeholder bias kill off what could've been great products except for the founder(s) ego(s).

not going live and keep on judging and re-building without any feedback

I did this once, it was my first release as PM & I didn't think about the ongoing operations & there was no backward compatibility. So the entire business was affected for 12 hours & we couldn't process any orders. (Learned from it, never made the same mistake again)

Not having an Ideal Customer Profile or a Target Audience

I've built a product that was great and everyone I told what it does was saying it's a great idea, but once released no one actually wanted to pay for it. It was some years ago a project to translate words you may not know in a foreign language in subtitles so that you can learn the language by watching movies and tv series. Technically perfect but not really monetizable.

NOt taking care and investing in social marketing.. we have a really superior product vs our competitors but yet no one knows us because we never invested in social media

waited too long to launch it and charge for it

We hired overseas to help us develop a new idea for a game. During testing, the product presented wasn't to our standards. Elements requested were added to the gameplay without flow and immersion. We had to pull the plug on the project and hire someone else that shared the same vision we have for the game. The game is still in development but when finished, we will have a quality product with a positive user experience.

Initially, we didn't manage the sprint. So we are not able to bifurcate what will be in the next release and when we can release our product. Then we started to manage the sprint and now things are so smooth!

Building an app for both iOS and Android in parallel was pretty intense in retrospect.