One interesting heuristic for promoting engineers or making "more-senior" hires for me has been: 1. Curiosity and interest in new tech, so they are keeping abr

One interesting heuristic for promoting engineers or making "more-senior" hires for me has been: 1. Curiosity and interest in new tech, so they are keeping abreast of developments and can think of modern best practices where useful. 2. Ability to ignore the new/sexy bits when it comes to implementation decisions, because the trade-off for stability/speed to implement is necessary in a growing company.