In a container transport system, wireless sensor networks (WSNs) can be used for monitoring products while they are being transported. To be commercially interesting, these WSNs must be integrated with enterprise systems of various actors in the supply chain. The need for interoperability between networks and partners, the heterogeneity of WSN technologies being used, and the mobility of sensor nodes make this integration far from trivial. This paper presents lessons learned from a research project in collaboration with industry in which we developed a prototype middleware solution for container transport. The prototype triggered valuable feedback which is highly relevant to consider when designing middleware for realistic sensor applications. Categories and Subject Descriptors C.2.4 [Computer-Communication Networks]: Distributed Systems--distributed applications; D.2.11 [Software Engineering]: Software Architectures--domain-specific architectures General Terms Design, Management Keyw...