Pros
The hours are great and it is nice to interact with a multicultural staff. The Montreal office is also quite aesthetic and you also have access to good group insurance. Development projects are really interesting, and there are a lot of good clients to work with (whenever you get the opportunity). Good place to start a career and get a window into international development (but would not suggest staying too long).
Cons
FinDev Canada is a new DFI (Development Finance Institution) in "startup" mode that is facing challenges related to culture. The mandate is currently geared towards growing the business, and as a result, there seems to be a lot of focus on being promoted and protecting job status (by perfection seeking and avoiding difficult conversations), rather than understanding clients and implementing impact in a real world context. If you work on the transaction side, you will need to have a strong sense of self-worth, maturity and a good personal support network in order to set healthy boundaries and manage insecurities (at all levels). You will need to take regular time off to re-align yourself with your values, practice self-forgiveness, and retain your mental health - as you will be tested often.