Sep completed his degree in Built environment: Bouwtechnische bedrijfsskunde at the Hogeschool van Amsterdam, specialising in Assetmanagement. In September 2021, he started as an intern at Spring Valuations. During this period, he successfully wrote his graduation thesis, in which he investigated the effects of changing laws and regulations regarding the energy label for investors' office properties.
After completing his internship, Sep continued working part-time. From 1 August 2023, he increased his involvement by joining the Spring Valuations Team full-time. In this role, he focuses on advising property owners on property valuations.