People who climb the ladder by scheming and sucking up don't last.
Tips
usage
Strongly pejorative. 投机 = seize an opportunity (often shadily); 钻营 = to bore into / push for a connection. Together they describe the archetype of an office climber.
mistakes
钻 here is read zuān (to bore / burrow into), not zuàn (drill bit). Same character, different tone.