ESO's User Portal: lessons learned

ESO introduced a User Portal for its scientific services in November 2007. Registered users have a central entry point for the Observatory's offerings, the extent of which depends on the users' roles - see [1]. The project faced and overcame a number of challenging hurdles between inception and deployment, and ESO learned a number of useful lessons along the way. The most significant challenges were not only technical in nature; organization and coordination issues took a significant toll as well. We also indicate the project's roadmap for the future.