For some reason, I find that for real engineering work a lot of work happens outside of fragment shaders. I think fragment shaders were romanticized far more than what they deserve.
Fragment shaders are perhaps over over-represented due to old WebGL style and easiness of integration, full screen quad + a shader is quite self contained setup.
Compute shaders are much more interesting and widely used in modern graphics though. No fixed rasterizing setup needed, just buffers for data in/out and a kernel with access to the usual GPU syncing primitives in between.
Side note that WebGL only doesn't have compute, because Google sabotaged the effort, asserting that WebGPU was right around the corner, so there was no need to adopt Intel's work into Chrome.
Shader parameter management, visibility and culling, shadow and lighting setup, scriptable pipelines, geometry shader orchestration, etc. There's a lot of work involved in preparing the stuff that you'll ask your shaders to, well, shade. But I wouldn't exclude shaders from "real engineering work", they're all parts of the whole.
