Historically, they've recommended Heroku... however, their dynos have a cold-start problem, causing your snake to sometimes timeout. I would recommend using an AWS free-tier instance if you have the option.
I remember that, they recommended a workaround last minute for it. Our snake depended on simulations so we just spun up a beefy GCP instance for a short period at the expense of a few cents.
hah! last year, for our bounty snake, we used a c4.2xlarge. Still, we could only manage a depth of 6-7 before hitting the response-time limit.