tl;dr:Critical for building a career as an engineer: (1) Strive to be the most valuable, but least critical i.e. you shouldn't be the point of failure. (2) Maintain an emotional equilibrium, especially as the larger your team gets, the greater the ups and downs. (3) Focus on growth and learning at every step — not on climbing the ladder. Raylene also provides advice for various roles i.e. junior engineers, ICs, tech leads, and more.