It's nearly the exact opposite of resource-constrained computing, but HPC / exabyte-scale storage type stuff has some of the same vibe of needing to know your hardware and wanting to squeeze the most out of it that you can. Consistently saturating a 100GbE link is a very different problem from dynamic data structure allocation on a microcontroller or whatever, but you have to care about some of the same sorts of things.
It's also possible to (for example) build 'normal' Web pages that load very fast, eg some of the main readable content is within the first few TCP packets, and the total page weight is <1% of typical. You won't get a medal, but it's fun, and sometimes the perf experts notice unprompted!