Focus more on code, not infrastructure: With FaaS, you can divide the server into functions that can be scaled automatically and independently so you don’t have to manage infrastructure. This allows you to focus on the app code and can dramatically reduce time-to-market.

Pay only for the resources you use, when you use them: With FaaS, you pay only when an action occurs. When the action is done, everything stops—no code runs, no server idles, no costs are incurred. FaaS is, therefore, cost-effective, especially for dynamic workloads or scheduled tasks. FaaS also offers a superior total-cost-of-ownership for high-load scenarios.

Scale up or down automatically: With FaaS, functions are scaled automatically, independently, and instantaneously, as needed. When demand drops, FaaS automatically scales back down.

Get all the benefits of robust cloud infrastructure: FaaS offers inherent high availability because it is spread across multiple availability zones per geographic region and can be deployed across any number of regions without incremental costs.

https://www.ibm.com/th-en/topics/faas