Microsoft

If you work on the Windows group, you will get access to millions of lines of heavily cluttered code. Within a few months, you will develop the ability to work through such complicated and convoluted code. In the future, someone who has always worked on a clean codebase competes with you; they will struggle, whereas you will shine :)

If you leave MSFT for a different organization whom MSFT perceives as a competitor (the other company may not reciprocate this perception :)), then they will pay you in full for your entire notice period and also waive off the notice period. So you get amazing benefits when you leave :) to the right company.

Heavily bureaucratic.

Manager-centric performance system. This performance management system is tailored to manufacturing shop floors, not to a collaborative software development company. What you need is a peer review system, not a manager-centric system.

Engineering systems within Microsoft aren't even remotely close to those at Google, Facebook, or Twitter with respect to the exposure that you can get as an engineer.