The "How it works under the hood" section raises more question than it answers. What is the difference between step 3 and step 4? As described, step 3 goes from LLVM IR to BPF (via llc), and step 4 - goes from LLVM IR to eBPF bytecode? That's nonsensical.
I'm the co-author.The code is in a very very bad state right now, but the architecture is pretty ok to explain. In step 3, we translate from the Python frontend to the LLVM IR. In step 4 we compile it down to an object file using the LLVM backend `llc`. This object file gets loaded into the kernel and it is what actually contains the eBPF bytecode.
You may want to edit the blog post, then, because that's not what it says.