I used to work on this kind of stuff a lot. For visualizing laz, I wrote “displaz” and the julia binding GitHub - c42f/Displaz.jl: Julia bindings for the displaz lidar viewer which might be helpful if you want to visualize large point clouds. (The design goal was to gracefully handle point clouds up to the size of available RAM.) The project is a little abandoned now that I’ve moved on to other things, but I did release a julia 1.0 compatible version.
GitHub - KristofferC/NearestNeighbors.jl: High performance nearest neighbor data structures and algorithms for Julia. is invaluable for spatial search.
There’s also several basic but useful geometric utilities at Fugro Roames · GitHub which I was peripherally involved in for example https://github.com/FugroRoames/Rotations.jl and GitHub - JuliaGeometry/CoordinateTransformations.jl: A fresh approach to coordinate transformations..., and beginnings of a julia-native geodesy library at GitHub - JuliaGeo/Geodesy.jl: Work with points defined in various coordinate systems.
JuliaGeo has a bunch of cool stuff including various wrappers for highly respected open source geo libraries, etc.
All this is just my personal (and somewhat out of date) perspective. I’m sure there’s plenty of great tools I’ve left out.