Of the top of my head: 1) Lack of libraries. 2) Little to non-existent tooling & observability support. 3) Lots of challenges around gRPC. That it needed a d

Of the top of my head: 1) Lack of libraries. 2) Little to non-existent tooling & observability support. 3) Lots of challenges around gRPC. That it needed a discovery service such as etcd was a big source of pain. I remember two or three massive downtimes where an adjacent team went through hell for a day just to get back a high throughput system back online. gRPC + etcd was very susceptible to thundering herd problem. 4) Lack of experienced developers who would guide others idiomatic way of doing things. And related, go routines need a different mindset and somewhat a grounds up re-learning. The code would routinely get into deadlock sort of scenarios. I conceded that most of the above are not inherent to Go but to any new system/language. I'm sure they all have been addressed now as the language and ecosystem has matured. That was the point I was trying to make though; don't jump onto a new bandwagon. Of course you want to learn it on your own and experiment that's totally fine but to use it in production is fraught with risk IMO.