This is the MVP of MVP
Step 1: subscribe to relevant FB/LI groups. For SAAS, I'd recommend the Facebook group: "SAAS growth hack".
Step 2: find a screenshot of a UI that could be your product. You can spend some time on Powerpoint, or even just take an existing UI and blur it a little.
Step 3: ask the group something that looks like: "We built this homemade tool that solves X at our company, we considered sharing it, anyone interested?"
Step 4: take note
Below are some examples of people who did exactly this 👇