Designing and building a mobile service robot is a complex task, involving many design decisions regarding hardware components and software architecture. A robot design always constitutes a delicate compromise between capabilities, performance, safety, reliability and costs. Only the availability of high-quality robot middleware frameworks like ROS has allowed several university groups to succeed in this task. In this paper, we describe the hardware and software design of the Domestic Robot of project Robot-Era, a medium cost mobile manipulation platform designed to help elderly people with their daily routines in an assisted living environment. Assembled from standard hardware components, the robot is characterized by its services-based software architecture, which integrates three different software frameworks, exploiting the strengths of each. We highlight the development process as well as some problems that occurred during the design, implementation and testing phases.