Pros
Nice working environment, free fruit and drinks provided, massage therapist who came in once a week.
I had ownership of some big, complex projects which really boosted my career, and still look impressive on the CV 3 years on.
They took a chance on me when I had no experience
Lovely colleagues who regularly skipped lunch to teach me
Cons
The only reason I got the big projects is because the complexity of the work was massively underestimated. I received no recognition for it within the company and I was actually told by one of the directors that if I was able to do it then it must be easy.
No training or support from management. I was actively discouraged from skilling up by some company directors.
Huge amount of bureaucracy and red tape, especially around finance/purchasing and timesheets. Much worse than any of the large companies I have worked for since.
Very top heavy management structure
Little to no opportunity to advance internally