We report on experience that we made in the Trading room InteGRation Architecture project (TIGRA) at a large German bank. TIGRA developed a distributed system architecture for integrating different financial front-office trading systems with middle- and back-office applications. We generalize the experience by proposing an architectural style that can be re-used for similar enterprise application integration tasks. The TIGRA style is based on a separation of data representation using domain-specific XML languages from transport of those data with an appropriate middleware. We show how Markup languages, particularly the eXtensible Markup Language (XML) and eXtensible Stylesheet Language Transformations (XSLT), can be used to solve semantic data integration problems. We discuss that the strengths of middleware and markup languages are complementary and indicate the synergies yielded by deploying middleware and markup in the TIGRA style.