Abstract: A method performed by a computer to update a runtime environment of an application of the computer via a communications network, wherein a filesystem of the runtime environment comprises one or more layers, wherein at least one layer of the one or more layers comprises a link layer formed by a plurality of packages and wherein the link layer comprises symbolic links indicative of the packages forming an updated layer. The method comprising receiving, from a user device or from a scheduling unit, a first signal indicative of a command to use the updated layer of the one or more layers, obtaining the updated layer, obtaining packages forming the updated layer, from a local cache or from a shared storage or from an image repository node, and updating the runtime environment by replacing a layer of the one or more layers with the updated layer using the obtained packages.