1. Humans perform best if they have ownership over a slice of responsibility. Find roles and positions within the company which give you energy. Being "just another intern/junior" is unacceptable, you must strive to be head of photography, chief of data security, master of updating packages, whatever makes you want to jump out of bed in the morning. Management has only one metric to perform on, only one right to exist: Coaching people to find their optimal role. Productivity and growth will inevitably emerge if you do what you love. — Boss at current company

2. Don't jump to the newest technology just because it's popular or shiny. Don't cling to old technology just because it's proven. — Team lead at the Arianespace contractor I worked for.

4. "Developing a product you wouldn't like to use as an end user, is unsustainable. You can try to convince yourself and others that cancer is great for weight loss, but you're still gonna die if you don't try to cure it. You can keep ignoring the disease here to fill your wallet for a while, but it's worse for your health than smoking a pack of cigs a day." — my team supervisor, heavy smoker, and possibly the only sane person at Microsoft.

5. Never trust documentation, never trust comments, never trust untested code, never trust tests, never trust commit messages, never trust bug reports, never trust numbered lists or graphs without clearly labeled axes. You never know what is missing from them, what was redacted away. — Coworker at current company.