Processing such large datasets as OSM is a tricky business. In this talk I would love to tell a story about a set of optimisations and tricks that allowed to reduce graph building time for Valhalla routing engine from 22h to 7h. It's a story about C++, OSM and geospatial data and how obvious things can lie unnoticed without a proper tooling - or how to measure performance on such scale and find what to fix.