IMO CTOs must have a broad knowledge of how things are done in all the fields, eg. web, mobile, backend, devops, nowadays ML etc. That way they can take more sa

IMO CTOs must have a broad knowledge of how things are done in all the fields, eg. web, mobile, backend, devops, nowadays ML etc. That way they can take more sane high-level and long term technological decisions. Otherwise you end up with a cto asking you to move everything on microservices for your 1k users app because he/she heard of a friend's company using them (based on a true story)