Depends on which country you are in and which project you are on. In Australia there will likely be a National Police Check, if on a government project you'll also need to do additional checks for your security clearance.
Improving all the time, they are actively working towards a better culture in Australia at the moment. That said, it's pretty good already (coming from someone who joined a year ago) and there is a strong focus on learning and personal growth. In Ballarat I find diversity is highly valued and everyone I have met so far is inclusive and supportive of their co-workers.