Paul Johnson has been writing software since the early 1980s on machines ranging from the ZX81 and servers to his trusty Mac, and has used more languages than he can remember. He is a qualified scuba diver and college lecturer. Paul lives with his wife, kids, and pets, and listens to an inordinate amount of rock and metal on Primordial Radio. This is his third book for Packt. Vesa Kaihlavirta has been programming since he was 5, beginning with C64 Basic. His main professional goal in life is to increase awareness about programming languages and software quality in all industries that use software. He's an Arch Linux Developer Fellow and has been working in the telecom and financial industry for over a decade. Vesa lives in Central Finland, in Jyvaskyla. Vesa worked on the final editing phase of Learning Rust.