I wrote a flaky test management system called https://www.flaptastic.com/ on AWS Lambda... my first AWS bill was $2.50. I love it. I also used serverless.com's wrapper to deploy it for free. If this gets expensive and I want to raise money to have expensive DevOps engineers setup Kubernetes for months then fine... but I really don't need that and I can easily port this to any other platform if I want to later.