Dealing with a lot of traffic for a small team isn't hard in itself. If it is easy to parallelise you just need to horizontally scale. And most concerns can be added as sidecars or middleware. Rate limits, auth, etc. Basically this is a kubernetes cluster. For a 3 person startup hard. For 50 pretty managable.
And if you were a smaller team then you don't even need K8s. Just ECS or Cloud Run have simple abstractions for horizontally scalable services and sidecars support.