Improve and maintain a customised ROR Project -- 2

We need a retainer to help us build and improve our existing project... We have comprehensive ROR portals which need certain modifications, improvements, and maintenance. Need to improve user experience, build additional support portal, build a financial portal for billing. Need someone who is full-stack and can support us on regular basis. this is a month-on-month project. Should be able to manage the project end to end. Rails version 6