A key element of Spring is infrastructural support at the application level: Spring focuses on the "plumbing" of enterprise applications so that teams can focus on application-level business logic, without unnecessary ties to specific deployment environments.
It is a modern, JVM-based, full-stack framework for building modular, easily testable microservice and serverless applications. It features a Dependency Injection and Aspect-Oriented Programming runtime that uses no reflection.
Go is expressive, concise, clean, and efficient. Its concurrency mechanisms make it easy to write programs that get the most out of multicore and networked machines, while its novel type system enables flexible and modular program construction. Go compiles quickly to machine code yet has the convenience of garbage collection and the power of run-time reflection. It's a fast, statically typed, compiled language that feels like a dynamically typed, interpreted language.
Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run". We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.
Javalin started as a fork of the Spark framework but quickly turned into a ground-up rewrite influenced by express.js. Both of these web frameworks are inspired by the modern micro web framework grandfather: Sinatra, so if you’re coming from Ruby then Javalin shouldn’t feel too unfamiliar.