The first MTCA.4 LLRF system at DESY has been tested at the Free Electron LASer in Hamburg FLASH back in 2010. Since then, more and more accelerator facilities within DESY have been equipped with this technology. Today, the European XFEL is operated with a LLRF system consisting of more than 50 MTCA.4 crates. Maintaining all facilities in a twenty-four-seven on-call service allowed us to gain a lot of experience with these system over the last years. Especially the operation in a radiation prone and non-accessible environment demands a continuous improvement of the reliability and development of automation routines. As a next step an upgrade of parts of the LLRF systems at FLASH is planned which are in operation since almost 10 years.