I was always employed by small companies so far, but I’ve consulted big ones. I think one benefit of working for a small company is that you “are somebody”, people know and (hopefully) respect you. You can feel the impact you make. And probably there’s less bureaucracy.

I've mostly worked for smaller companies and I think the main difference is the amount of autonomy you'll have versus the amount of time you have to get work done.

In a large company jobs are more specialized so you might be the one person/team that works on a specific part of the software. This means that most of your time will be focused on that specific part.

In a small company usually you'll have to wear more hats. This means you'll have less people to worry about to get things done, i.e. you don't need approval from your boss's boss's boss, but it also means you'll be spread over a larger surface area of the business and have more responsibilities.

There's nice aspects to both, in a small company you learn a lot! Both about your co-workers' problems and your customers' problems, as well about how to solve those problems with less resources. While in a large company you have more resources and thus more ability to focus on a specific piece and make it fit into the rest of the system.

It all depends on the team. Big company, small company... I find they are mostly the same and have very similar problems; though, smaller companies obviously have fewer degrees of separation between you and the "problems." But, my direct team has always been the main differentiator. Though, small companies typically allow you to wear more hats than what's often possible in larger companies - which I like a lot.