Petra graduated in Leiden in 1989. She started her career as a lawyer at NautaDutilh. In 2011 Petra set up her own law firm, specialising in employment law. Lanser legal profession has an informal alliance with Sørensen Advocaten, situated at the same address with adjacent office spaces. From the same background, there is optimal cooperation on quality, including the exchange of expertise. The high standard of quality and commitment are the common denominator.