And for a sample of the writing, here's the section on compiling the CLI tool jq to WebAssembly: http://levelupwasm.com/sample-jq.pdf (though note that it builds on previous material so it doesn't re-explain everything)
Edit: Also, if you're curious about using WebAssembly in genomics, check out https://github.com/robertaboukhalil/aioli/ and https://github.com/robertaboukhalil/fastq.bio, a tool to get a preview of DNA sequencing quality that uses WebAssembly to speed up the analysis portions.