I've been in a similar boat. We've been splitting up or converting large Python 2.6/2.7 applications into Go services (and doing the same to large Perl applicat

I've been in a similar boat. We've been splitting up or converting large Python 2.6/2.7 applications into Go services (and doing the same to large Perl applications) for a long time now. Go has consistently been 10-20x performant (allowing for dramatically reduced hardware needs), easier to maintain, and more productive to produce code in than our previous Python (Twisted) and Perl (AnyEvent). Hopefully KhanAcademy has solid telemetry data in both legacy and new code so they can quantify benefits. They will also have a learning curve for managing multiple micro services vs monoliths. Accessing shared data will be a problem they will likely have to solve. We've opted for each service controlling its own data - no reaching into another service's data behind its back. Everything through APIs. This gives the microservice the ability to alter its datastore as it needs to and not be blocked by other teams' need to update how they access the data. Debugging a distributed solution is much harder than a single service. Distributed tracing, consistent structured logging with log aggregators that let you do fancy searches (like Splunk), and application telemetry and metrics will be even more important than before.