Some may find the mix of newer technologies and legacy / older technologies a bit frustrating. The company's been around a long while, so this is a normal part of technology. The company has clear plans on migrating older systems to newer technologies/patterns, but this will take time. A developer that feels they can only work on new development or that is biased towards one language/technology or another, may not be super happy in the end.
Optima focuses on hiring only the best talent (top 10%). If someone is used to being the lead, and comes into the job as a new team member with that expectation/attitude, they will be unhappy. I came into the job with 20+ years experience. Outside of Optima, this is something special. At Optima, that can be the norm (e.g. most of your team is as or more experienced than you...). Your position on the collective team at Optima is based upon your contributions, not your years of experience.