The success of the European integration community is significantly attributed to the success of its judiciary. The Court of Justice of the European Union has played a crucial role in the development of the European legal community through early landmark decisions and a jurisprudence characterized by remarkable design, coherence, and continuity. The preliminary ruling procedure is described as the most important procedure within the European legal order. It establishes a connection to national courts and forms an interface between national law and Union law, allowing for joint adjudication. After initial hesitation, the vast majority of decisions from the CJEU are now made through the preliminary ruling procedure. This work examines cooperation and acceleration mechanisms within the preliminary ruling system. In which direction are these mechanisms currently developing? To what extent can they be brought together, including for mutual enhancement, to further develop the preliminary ruling procedure? Is it possible to achieve a stronger involvement of the national judge in the proceedings before the CJEU without fundamentally altering the successful nature of the preliminary ruling system?.