I’m working as a freelancer for opendi AG (Munich), where I did set up an OSM Rendering-Server with Mapnik/PostGIS.
Performance after initial setup was way too slow, so i’ve done some work for rendering speed tuning. I’ve written a small How-To because i haven’t found one in the OSM-Wiki:
Having some ideas for improving PostgreSQL performance too? It’s a wiki, add it ☺