Pros
Redknee tried to keep the start-up mindset. The domain is multi-disciplinary requiring both new technologies but also legacy stuff which makes it interesting both for beginners as well as for seasoned engineers. If you can get pass the hiring companies used like DevFactory they will pay you good and actually the environment is so much chaotic you just keep calm and get lots of money (if you are in a 3rd world country) otherwise see below.
Cons
Too much politics due to leadership constellations after each acquisition from Nokia Siemens and Orga GmbH and this in a very harsh competitive market... yield Redknee to nearly bankruptcy and (hostile) takeover from ESW group. As of now Redknee/Optiva does their internal works only using outsourcing companies. If you work for one of these companies and you are junior you have no time/chance to step in and learn/solve your work. If you are seasoned you are confronted continuously by delivery "continuous nonsense" due to metrics/KPI'S of these companies which eventually has nothing to do with the core business and finally you are in a limbo situation. There is an illusion of work being done especially in innovation but it is nothing more than achieving the internal KPI's of the engineering managers and marketing mock-ups or MVP's as finished products.