3-4 years is also about my tolerance for the run-of-the-mill bullshit and bureaucracy and politics at any company. I need a fresh slate every few years as well.

3-4 years is also about my tolerance for the run-of-the-mill bullshit and bureaucracy and politics at any company. I need a fresh slate every few years as well. Interestingly, my worst career experience was at a company with ~30 people. So you don't necessarily need size to produce bad results.