Avantages
Checkout.com provides an exciting, fast-paced and oft-times challenging work environment. Individuals can have a meaningful, lasting and very much apparent impact on the company and the high visibility of one's contribution can be extremely satisfying. Few can claim to be mere 'cogs in a wheel'. The rapid growth of the company means that the scope and diversity of one's role is constantly evolving, which makes it unlikely you'll get bored anytime soon. Management is also very much supportive of (and indeed actually encourages) people taking full responsibility for their initiatives and allowing them to deliver with minimal intervention or hand holding. For people keen to assume ownership of a project and run with it, it's a great place to be. As part of this environment, the various teams are also extremely approachable and used to working together; the numerous team trips and extra-curricular activities organised around the year certainly help to maintain this open, collaborative set-up. Without a doubt, it's the best job I've had in my >10yrs of working life.
Inconvénients
There is a lot of pressure to perform, and people are certainly held accountable for their actions. The workload, coupled with a permanent expectation for high standards of delivery can be tough to deal with. That said, I believe strongly that Checkout.com acts in a highly meritocratic manner - I've never seen anyone be treated unfairly when it comes to assessing their contribution to the company. It's also worth mentioning that management definitely lead from the front in this regard, as they never expect anything from others that doesn't also apply to themselves.