title: Elixir - informing other applications about events
body: <p>Let's assume that I have a system (elixir application) that downloads data from the internet, then it will unpack the data (e.g. gzip), parse it (e.g. to get some metadata) and finally will put that data into some local database. After that, the system could be used by other applications (e.g. they can query the data from the system). As we can see, from start till the data is ready to be queried there is some undefined amount of time needed.</p>
  <p>Question: what would be the best way in Elixir (pattern/behavior/?) to inform other modules (in a separate application), that the data is now ready in the described system?</p>