This chapter demonstrated a use case by showing how we can develop a mobile payment system on FaaS platforms.

We used Parse as a UI backend. Then we connected Parse to a bank routing function running on Fn via the Parse WebHook mechanism. We then demonstrated that with functions, it was relatively easy to make a call to a modern infrastructure such as blockchain. We simulated two banks to show use cases of a function, a function as a Glue, and a function that wrapped legacy systems. Then we demonstrated how a function was used in conjunction with a streaming agent to process data streams.

All of the three FaaS platforms were linked together and run on the same Docker Swarm cluster. It was quite simple to link OpenWhisk and OpenFaaS functions together, but in the case of Fn, it was a bit of a hack because the current version of Fn doesn't allow you to define a container network.

The next chapter will be the final chapter of this book. We will conclude the concept of a function and look forward to see what's next beyond the world of FaaS.