Can't speak for cars specifically, but other software built to comparable standards requires a super rigorous process including detailed specs, risk analysis an

Can't speak for cars specifically, but other software built to comparable standards requires a super rigorous process including detailed specs, risk analysis and mitigation, detailed design, comprehensive automated and manual testing against the soec including test coverage, tons of documentation on everything and finally a third party certification on everything. The process is so far removed from typical web and business slop that it's an entirely different world of its own.