Once you start working with Big Data systems, you discover a whole bunch of problems you won’t find in monolithic systems. Monitoring all of the components becomes a big data problem itself. In the talk, we’ll mention all of the aspects that you should take in consideration when monitoring a distributed system using tools like: Web Services, Spark, Cassandra, MongoDB, AWS. Not only the tools, what should you monitor about the actual data that flows in the system? We’ll cover the simplest solution with your day to day open source tools, the surprising thing... that it comes not from an Ops Guy.