Pros
Growing by 80-100 employees per year in the last 3 years while remaining profitable and well organized. New employees have brought incredible strength in engineering and project management especially. Atypon gives its people a lot of creative freedom in how they do things. Pay is fair. Incredible retention means that the company maintains its culture while it is growing. Wiley's acquisition hasn't be felt at all. Instead, the company got another demanding client (Wiley) that wants a lot of new things and everyone is excited about it. Everyone is respected and everyone is expected to work hard. The ones who are respected the most are the ones who come up with ideas on how to improve their operations. What they don't expect is that they will be asked to lead their proposals, which is a lot of fun if you really like this thing.
Cons
A few: Vacation packages in the US start low for new hires, but they can be negotiated for senior people. They are especially good for people who stay a long time. Obviously given how many years people stay, they don't seem to mind.