irc-books/docs/services.dot

digraph Services {
   node [shape=rect];
   rankdir=LR;
   IRCClient
   FileFetcher
   Unpacker
   WebAPI
   BulkInserter
   S3
   DB

   WebAPI -> IRCClient -> FileFetcher -> Unpacker -> S3
   Unpacker -> BulkInserter -> DB
}