> Every call across components acrues failure modes, requires a slow march through (de)serialisation libraries, a long trek through the kernel’s scheduler. A TLB cache invalidation here, a socket poll there. Perhaps a sneaky HTTP request to localhost for desert.

And this has tangible costs, too. I saved more than $10k a month in hosting costs for a small startup by combining a few microservices (hosted on separate VMs) into a single service. The savings in development time by eliminating all of the serialization layers is also appreciable, too.