I have a software product in alpha/beta stage. I want to test the current minimum viable product. I want the prototype to be tested by a large sample size, so I can gain feedback, suggestions, find problems, and build on my current prototype. My goal is to achieve maximum product - market fit, and pivot if necessary. What are the challenges to doing this and are there any services currently available ?
You can get real people to interact on a site like usertesting.com — it's a paid service to get you real feedback from real humans.
If you want access to your demographic, you'll need to find out where they hang out and come up with an offer to encourage them to try your service (a closed beta, free access in exchange for submitting evaluations and feedback, etc.). Ads and/or sponsored posts could be useful here.
Or you can set up your own user testing arrangement and offer to pay people a small amount in exchange for using the app. This should probably be your last-ditch effort, though.