Recent developments in high-speed networking and PCIe-mounted accelerator cards have made possible new backend designs that provide vastly improved flexibility and capability in signal processing for radio astronomy. While direct digitization close to the receiver improves the quality of the physical signal by reducing analog transmission and filtering losses, it also enables the building of a backend based on commercial-off-the-shelf (COTS) hardware that is able to exploit modern cloud computing paradigms. In the Effelsberg Direct Digitization (EDD) project we are developing a versatile backend that takes advantage of these benefits. The EDD backend orchestrates data processing on COTS computing systems hosting GPUs as well as FPGA that can be rapidly and easily adapted to a wide range of observing use cases, e.g. spectroscopy, polarimetry, pulsar timing, etc. The highly modular system uses a unified interface for the control of its subsystems. This interface abstracts the telescope into well defined components which allows for a universal design suitable for deployment at any radio observatory only minimal customisation.