Guinea pigs in the time of COVID?

I have built an MVP of a distributed computing platform for Python, Fastmap. The one thing that's missing, as I'm sure we have all been through, is users.

This problem is extra complicated for me. Being a distributed computing platform carries two important risks. First, there is a security risk - I run untrusted code. Second, there is a financial risk - user tasks can be of any size and virtual machines can get expensive fast.

I have made efforts to address these risks but mistakes are always possible. Therefore, a slow rollout seems prudent. Additionally, a slow rollout gives me the flexibility to adjust the interface according to user needs.

Given that my product that would only interest a subset of engineers, data scientists, and researchers, my market is already rather narrow. In non-COVID times, the obvious solution would be to attend every tech meetup available and talk with as many people as I can. However, it doesn't look like that will be possible again for a few months and I've yet to attend a good zoom meetup.

So my question is, where do you go to find guinea pigs to test your product? What's the playbook here? Reddit, Hackernews, Indiehackers, etc are all possible, yes, but ideally I'm looking for something more targeted.