As things stand, the UK is set to leave the EU on 31 October 2019. An earlier departure or further postponement are however still possibilities. If you are travelling between the EU and the UK for conferences and events in the coming months, it is recommended that you keep yourself informed of official advice.
The British and German governments and the European Commission have all published information online about how UK - EU travel is expected to work in the foreseeable scenarios.
Links below are for your convenience.
British Government: Department for Transport live website
German Federal Foreign Office article published 4 Apr 2019
European Union: Publications Office article published 5 Dec 2018