My thoughts
Interesting take on setting up an HTTP service. They mention that using grpc or different protocols might require to adjust the structure. I would be curious to get their take on a service supporting grpc and HTTP to help me revisit older decisions.
The signal.NotifyContext(ctx, os.Interrupt) approach to cancel context on interrupt is really an improvement over starting a goroutine and using Notify with a channel.
Best advice is to not use global scope to allow parallel testing without sporadic failures. Usinh os.GetEnv by passing a func(string) makes so much since.
Read the article: How I write HTTP services in Go after 13 years