In a typical startup you are going to be strapped for cash and time. You need to optimize and compromise. In general, if you don't know how do something, then figure out if you need to learn it, or whether you can get by with a "good enough" solution, because there will be a queue of other things you need to do that might be more business-critical.
So if you already know Kubernetes, then great, use it. Leverage your existing skills. If you don't, then just use Heroku or fly.io or whatever, or go with AWS if that's your competence. Maybe revisit in a year or two and maybe then you'll have funding to hire a devops person or time to spend a week or two learning to do it yourself. Right now you want to get your SAAS MVP in front of customers and focus on the inevitable product churn of building something people want to pay for. The same advice goes for anything else in your stack. Do you know it well enough? Do you need it right now? Or is there a "good enough" alternative you can use instead?
So if you already know Kubernetes, then great, use it. Leverage your existing skills. If you don't, then just use Heroku or fly.io or whatever, or go with AWS if that's your competence. Maybe revisit in a year or two and maybe then you'll have funding to hire a devops person or time to spend a week or two learning to do it yourself. Right now you want to get your SAAS MVP in front of customers and focus on the inevitable product churn of building something people want to pay for. The same advice goes for anything else in your stack. Do you know it well enough? Do you need it right now? Or is there a "good enough" alternative you can use instead?