anchor.diff:  *** replace Lists and Strings by arrays
   *** cryptography is slow
   *** XML parsing is slow
  -*** serializin/deserializing is slow
  +*** serializing/deserializing is slow
   *** creating a regexp is slow
   *** prefer StringBuilder over String.format
   *** avoid polling
  
positive.code: **** at-most-once if you can afford losing messages
  **** at-least-once (+ message numbering) otherwise
  *** use async I/O if you can
  
  * Less frequent sources of performance issues
  
  
negative.code: * performance improvement process (see JPT)
  ** no premature optimization
  ** have a performance objective
  ** concentrate of the 20% of the app that is responsible for 80% of the load
  ** one issue often hides other issues
  ** first actions might not show any improvement. Yet, don't despair!
  ** test in real-life conditions (DB size, # simultaneous users, server sizing...)
  ** OS contention, then GC issues, then code optimization
  ** ...
  