can't get anything done quickly because there are processes in place to make sure you don't do things maliciously or just mess up.

boring long meetings that are nearly incomprehensible.

you are not allowed to go work on anything that you can do that the company has decided is not in the skill-set they want you to exercise therefore your skills atrophy.

someone else has made the choice how you should solve a problem, and that choice is idiotic in your opinion.

target for attack to shut down your systems

big company pros -

generally great food cheap.

generally pension, bonuses, insurance.

small company cons -

since no processes in place to keep people from doing stupid things sometimes someone does something stupid and everything is ruined.

sometimes moving to fast and breaking too many things so no time to stop and talk about what you are doing.

you will have to go outside your skill-set to get things done which is stressing.

small company pros -

probably your choice how you want to do anything.

sometimes there is the idea that you will build the small company into a big company which can be exciting.