Hardware management by the provider is the key to a serverless architecture. The only challenge for users is to integrate their software, including the corresponding functions, into the rented cloud structures. These functions can be called:
- asynchronously via events
- or synchronously, based on the classic client-server model.
The former has the advantage of preventing excessive coupling of individual functions, minimizing the resources required. One example of an event-based function is generating a thumbnail whenever an image is uploaded. In the classic method, the client has to send a separate request to the server to call a function and to create the thumbnail.
Unlike the platform-as-a-service infrastructure, the serverless computing provider does not continuously deliver a persistent working environment for the entire term of the contract, instead of delivering the resources required for the runtime of an individual function call. Of course, there are physical and virtual servers running in the background (though they remain unseen by users) to allow the functions to be executed.