On Jobspotting, you can browse a rather small variety of (5 job offers) in Wildau. Subsections include most dominantly Merchant and Retail. The most cited skills for these jobs are Retail, Sales Promotion, and Lead Generation. Are you familiar with them?
Those looking for senior Sales job offers will be glad to hear that 80% of roles in this area are for seasoned applicants. At the moment, internship positions are thin on the ground in this area. By signing up to Jobspotting, you'll be notified as soon as one shows up. Among the companies who look for Sales employees, there are currently no startups. Why not have a look at jobs in another country to compare and contrast opportunities. Just use the Explore tab.