Memory management errors are responsible for 70 to 80 percent of security vulnerabilities1 2. This would be much less of a problem if computers were running more Rust and less (if any) C code. So do we rewrite every widely used C project in Rust? Doing so entirely by hand is infeasible. Doing so in an entirely mechanized way is impossible. Between these extremes lies a point that strikes the optimal balance between the efficiency of automation and the intelligence of humans.