Nimbus: Improving the Developer Experience for Serverless Applications

We present Nimbus, a framework for writing and deploying Java applications on a Function-as-a-Service ("serverless") platform. Nimbus aims to soothe four main pain points experienced by developers working on serverless applications: that testing can be difficult, that deployment can be a slow and painful process, that it is challenging to avoid vendor lock-in, and that long cold start times can introduce unwelcome latency to function invocations. Nimbus provides a number of features that aim to overcome these challenges when working with serverless applications. It uses an annotation-based configuration to avoid having to work with large configuration files. It aims to allow the code written to be cloud-agnostic. It provides an environment for local testing where the complete application can be run locally before deployment. Lastly, Nimbus provides mechanisms for optimising the contents and size of the artifacts that are deployed to the cloud, which helps to reduce both deployment times and cold start times.