The idea behind such a solution is to consider how often/how long a service is called. For example, suppose you have a shop and you have special discounts during the Easter and Christmas holidays. It does not make sense to have the special discount service active all the time, as it would result in a loss of money. It would be nice to have an infrastructure that deploys your service on demand when other services request it. That's the main point of being server less, and it deals well with microservice and cloud environments. Big cloud vendors provide these new technologies, some of which are as follows:

• AWS Lambda
• Google Cloud Functions
• Azure Functions