We talked about the overall design of an online shopping store that can scale starting with our post here. Then we proceeded to discussing data infrastructure and data security in a system design case in previous posts. We started looking at a very specialized but increasingly popular analytics framework and Big Data to use with data sources. For example, Spark and Hadoop can be offered as a fully managed cloud offering. we continued looking at some more specialized infrastructure including dedicated private cloud. Then we added  serverless computing to the mix. Today we continue the discussion.
Serverless computing is open by design.  The engine and the event emitter/consumer is open. The interface is open. Its components are Docker, Kafka, Consul which are all open The tools used with this are also open.  
Since the emphasis is on actions, triggers, rules and the deployment and runtime are managed, it is easiest to upload and use it. Actions are the event handlers. They can run on any platform. Typically they are hosted in a container. They can be changed to create sequences and to increase flexibility and foster reuse. An association of a trigger and an action is called a rule. Rules can be specified at the time the actions are registered. A package is a collection of actions and triggers. It allows you to outsource load and calculation intensive tasks. This allows share and reuse. The only drawback is that troubleshooting is more tedious now as there is more correlation to be done. However, actions can be both synchronous and asynchronous and expressed in their own language and runtime. This means we can get responses in blocking and non-blocking manner.  The runtimes are found in the container hosted. 
In the standalone mode, the containers are made available with VirtualBox. In the distributed environment, it can come from PaaS.  These actions do not require predeclared association with containers which means the and the infrastructure does not need to know what the container names are. The execution of the action is taken care of by this layer.

#codingexercise
A bot is an id that visits the site m times in the last n seconds. Given a list of entries in the log sorted by time, return all the bots id.
Hashtable<int, int> GetBots(Log[] logs, int m, int n)
{
var h = new Hashtable<int, int>();
var min = Math.min(logs[logs.Length-1]-n, 0);
for (int i = logs.Length - 1; i >= min; i--)
     if h.Contains(logs[i].id)
        h[logs[i].id] += 1;
     else
        h.Add(logs[i].id, 1);
foreach(var kvp in h)
      if (h[kvp.key] < m)
         h.Remove(kvp.key)
return h;
}