Jan Joost began his career at KLM, where he enhanced his skills as a Process Continuous Improvement Manager in aircraft ground handling and inflight catering production, leveraging an MBA background. Jan Joost's career then took him abroad, where he served as a Branch Financial Controller in diverse locations across Latin America and Europe.

Upon returning to KLM's headquarters, Jan Joost joined the dynamic team responsible for designing KLM’s flight network. Here, he had the opportunity to contribute to the landmark joint venture between KLM, Air France, and Delta Airways. Seeking new challenges, Jan Joost transitioned to the Aircraft Engineering & Maintenance Division as Controller Operations. This role allowed him to delve into Lean Six Sigma methodologies, discovering how they enhance process efficiency, reduce costs and improve quality.

In 2019, Jan Joost entered the realm of Shared Service Centres, tasked with outsourcing a portion of their captive SSC Finance Accounting activities to a third party. This experience was instrumental in his next endeavour: creating a Global Business Services (GBS) organisation. This initiative unified various Air France and KLM Finance and Procurement SSC activities, streamlining operations across the board.