Here, we describe a collection of genomic database portals, SoyBase (https://soybase.org), Legume Information System (https://legumeinfo.org), and PeanutBase (https://peanutbase.org), that support breeding and research work in the legume plant family. The legume family includes important crops such as soybean, peanut, common bean, lentils, chickpeas, as well as approximately 20,000 other species that are important in all terrestrial ecosystems. Beyond the value of the portals for species in this large clade (as well as for plant biology more generally), the database and site architecture of these portals will be of interest to developers of similar genomic sites, as the data management and software solutions are generic and should be applicable to a wide variety of organisms. The architecture for these sites has been designed for rapid, modular, flexible development well suited to genomic data and to rapid incorporation of new data. Website content is handled with a static site generator (Jekyll). Interactive applications are developed using javascript encapsulated as Web Components that access back-end data via APIs for stability and flexibility. This architecture allows for both code portability and for customization to serve the unique needs of each research community.