This work represents the essence of nearly 16 years of work in scientific computing for ocean and atmospheric modeling. This journey started at Alfred- Wegener-Institute for Polar and Marine Research in Bremerhaven, Germany, where – as a post graduate – I was assigned to optimize multi-grid solvers for elliptic partial differential equations evolving from ocean modeling. I am lucky and grateful that I had the chance to go all that way, to have the opportunity to explore the subject from many different angles, to have wonderful teachers and colleagues, and to have the chance to work and visit such exquisit places as the National Center for Atmospheric Research in Boulder, Colorado, USA, the Frontier Research System for Global Change at the Yokohama Institute for Earth Science (Earth Simulator) in Yokohama, Japan, the Max-Planck- Institute for Meteorology in Hamburg, Germany, the aforementioned Alfred- Wegener-Institute for Polar and Marine Research in Bremerhaven and Potsdam, Germany, the Technische Universit?at M?unchen in Garching, Germany, the Fields Institute in Toronto, Canada, the Naval Research Laboratory in Monterey, California, USA, the Department of Informatics at the University of Bergen, Norway and the Centre for Mathematical Sciences at the University of Cambridge, UK, to name only the most influential ones.