This Is What Most Companies Get WRONG About Promotion
2 types of promotion:
Strong companies: Already functioning at the next level
Weak companies: Mastery of current level + long tenure
In the best tech companies, each level is fundamentally different from the previous one. This is why promotion is lagging there: You need to be functioning at the next level consistently for 3-6 months before getting promotion.
The goal is to avoid the Peter Principle: Getting promoted to higher and higher levels until you are completely incompetent. When levels are truly meaningful, it's really easy to be doing great at your current level and then be struggling to survive at the next one.