The project linked.swissbib.ch aims to integrate the Swiss library metadata into the semantic web. A Linked Data infrastructure has been created to provide on the one hand a data service for other applications and on the other hand an improved interface for the end user (e.g. a searcher). The workflow for the development of this infrastructure involves basically five steps: (1) data modeling and transformation in RDF, (2) data indexing, (3) data interlinking and enrichment, (4) creation of a user interface and (5) creation of a RESTful API. The project team would like to highlight some challenges faced during these stages, and the means found to solve them. This includes for example the conception of various use cases of innovative semantic search functionalities to give specifications for data modelling, data enrichment and for the design of the search index. Data processing operations such as transformation and interlinking must be highly scalable, with the aim of an integration in the workflow of the already existing system. Wireframes have been made to realize early usability evaluations. Finally, negotiations have been undertaken with the various Swiss library networks to adopt a common open license for bibliographic data.