In 2016 in the keynote presentation of Spring One Platform, Juergen Hoeller announced Spring WebFlux, one of the most highly anticipated projects being worked on by the Spring Team due to the performance gains that reactive streams promised for web controllers. Subsequently, with Spring Framework 5.0, Spring Reactive MVC went GA along with the release of WebFlux API, making the reactive stream-based web controller mainstream.
Fast-forward to 2020, Spring WebFlux MVC has gained wide adoption in cloud-native applications, where developers strive for high throughput and low latency microservices. Clearly there has been a shift towards the reactive programming model, now that many of the database providers support reactive drivers where traditional blocking database calls are replaced by async and non-blocking back pressure aware data access.