Born in Hamburg, Buettner studied business management there and did an internship at a precursor of Vodafone, then started his career as a trainee at Axel Springer AG, where he worked on interactive media.
[2][4][5] In 2003 he and Blottnitz were awarded €203 million in damages by a California court for Bertelsmann's failure to pay them part of the proceeds from the sale of its share in AOL Europe; the amount was reduced to €160 million in an out-of-court agreement.
[2][3][4] In 2005 he bought a historic estate by the Baltic Sea for €7 million,[1][3][6] and converted the estate buildings and village into Grand Village Weissenhaus, a privately operated luxury resort which opened in 2014.
[4][7][8] Some of the funding for the renovation and conversion was raised on the crowdfunding site Companisto.de,[7][8] where it drew more investment than any other for-profit European organisation to that date.
[11] Buettner and five time world chess champion Magnus Carlsen announced in March 2024 that the tournament would expand into a yearly series of events with increased prize funds.