Specific technology choices aside, this was an incredible write-up of their migration process: thorough, organized, readable prose about a technical topic. It is helpful to read how other teams handle these types of processes in real production systems. Perhaps most refreshing is the description of choices made for the various infrastructure pieces, because it is reasonable and real-world. Blog posts so often describe building a system from scratch where all latest-and-greatest software can be used at each layer. However, here is a more realistic mix of, on the one hand, swapping out DBs for an entirely new (and better) one, but on the other hand finding new tools within their existing primary language to extend the API and proxy.

Great read. Well done.