The role of the Court of Justice in furthering the integration of the European Union is an unresolved topic of debate. This article contributes to the judicialization debate by assessing the impact of the Vander Elst Case‐law, which allowed third‐country nationals (TCNs) to be posted freely across the EU without work permits in the countries of posting. Based on Belgian posting data, we demonstrate that the ECJ introduced a mobility regime that is growing in importance and even outnumbers classical labour migration. We argue that judicialization not only results in ‘codification' of its case‐law or ‘modification' of it, but also in ‘Direct Design', whereby the Court creates new economic realities all by itself. While this regime further lessens the migration sovereignty of member states, the rising use of posting indicates at the same time the increasing role of the free movement of services in developing a single European labour market.