In order to be able to meet an extremely stringent time limit on the development of the Authentication Centre for the TACS mobile users of TIM, it was decided to utilise an object-oriented database viz. ObjectStore. We learned some positive lessons: it allowed us to cut on design time (database design, transaction handling, fault-tolerance, concurrency handling), gave us extremely high performance which allowed us further time for development and allowed us to serialise a server eliminating the need for deadlock detection. And we learned some negative lessons: unexpected problems (necessity of physical allocation schemes, address space), missing or poor features in the product (extent handling, versioning, scalability, ODMG compatibility, support for C++ STL). Since only a few members on the team had any knowledge of the workings of an OODBMS, the experience also proved the usefulness of OO technology whereby team members managed, nonetheless, to use the OODBMS successfully as it was encapsulated in the domain classes.