UX Expert - Web & Mobile Apps, Content, Landing Pages, User Inflow

Seeking a UX expert to help a development team with improvements to a 12-years old production system (SaaS). We'd like this professional to contribute with his expertise to the full user base inflow (from the website all the way to internal interfaces) (expected contribution on: Overall User Experience, Navigability, Efficiency, Simplicity, Professional presentation and others). This is an ongoing gig. If we like your work we're hoping we'll schedule your time as frequent as needed. Please bring updated know-how, best practices and overall good attitude (even though we've been in business for 30 years we're always striving to improve).