We are looking for a Software Development Engineer Senior, who will be responsible for middleware development, maintenance, and support with a strong focus on IBM App Connect Enterprise (ACE) and IBM Integration Bus (IIB). The ideal candidate will have extensive experience in high and low-level design documentation, gathering requirements from clients, and preparing technical specifications based on client requirements for developing message flow interfaces to integrate different applications. The role also involves implementing SOAP Webservices and REST APIs, integrating using MQ adapters, and dealing with various message domains like XMLNSC, JSON, and SOAP. Additionally, the candidate will develop message flows and use ESQL and mapping nodes for data transformation. The position requires a willingness to work in a Managed Services DEV Support team, and experience in the telecom domain is a must.