Fidessa has an extensive and global sell-side client base. This affords the opportunity to learn a lot about the areas of order management, market data, and execution management, but both equity and derivatives. Technical types can find opportunities in support, development, and implementations. The culture is pretty good, affording the opportunity to work hard, but also maintain a good work-life balance when needed.
Fidessa's U.S. operation grew significantly in the last decade, and recently went through a bit of a contraction with lay-offs. While not necessarily a bad thing, they now pay more attention to controlling expenses (i.e. employee salaries) than when the business was growing. It's also not quite as friendly a culture as it used to be.
Advice to those considering working there: Use Fidessa for personal career gain, and keep yourself available in the marketplace. They don't want "lifetimers" as employees.
Advice to Management
I suspect that by responding to financial pressures in the way management has, employees have lost some trust for that the company cares about them.