My fourth session of the day was a case study from Sirius International, where my old colleague Jon Gyllenswärd and friend and Jimmy Nilsson from factor 10 talked about a two year long change process they managed together. The process involved a complete system redesign, moving to a business optimal code base, cross functional teams and, sometimes controversially, always choosing the simplest solution possible.
Since this change process shares so many of the challenges we at eBay Sweden have faced or currently face during our change process, this session was mandatory for me and my colleagues. We have come a really long way (no thanks to me, I started working there in the end of May), but some of the choices we have made, have been quite different from the ones Sirius have made.
Before starting this huge change process, Sirius suffered from the technical debt of old, rigid systems. It held them back and some things were virtually impossible to achieve with these handcuffs on. Initially, they decided to build new features as totally separate satellite components, decoupeled from all other systems.
Surprisingly, as this model proved to work, they did not have to propose a system redesign to management. Instead, management eventually requested a complete system redesign, referring to the satellite project architectures.
The core principle has always been “when in doubt, try something very simple”. It has, at times, led to unconventional solutions and choices, like at times ditching databases altogether and instead write data directly to disk and load everything into memory. If it is easier to erase all data and recalculate than it is to store, why store? Dumping data to file with protobuf instead of storing it in a database made operations lighting fast, but required additional code for interpreting the binary data.
If the easy way works, go with it. If, however, things go wrong, take the hit and act directly, Dirty Harry style.
Having experienced many of the things Jon and Jimmy talked about, I enjoyed this talks and to hear about some of the more unconventional things the team tried out. The session was broad and at times very specific to Sirius, but than again, it was a case study. If you work in a situation like the one Sirius has undergone in the last two years, this video is a good watch.