The use of microalgae as a production system has gained huge interest in recent years. Recent research has concentrated on single aspects, such as the microalgal cells or the photobioreactors. The design of sustainable, effective, and economic processes for microalgal products requires the integration of microalgal biology including strain selection and genetic engineering, process, and reactor design and integration into environmental mass and energy fluxes. This involves tools of biotechnology and process engineering. Several attempts of such integrated processes have been developed. This review groups the integration aspects into several degrees of integration with respect to the classical upstream, bioreaction, and downstream steps. The integration levels consider metabolic, process, environmental, and social integration. At the end, the following question remains: How far can microalgal biotechnology help to solve the problems of feed, food, and fuel supply and contribute to a better society? Overall, this review gives an overview of the different stages of integration in microalgal processes. It is a guide towards conceptual positioning and planning of microalgal plants. Furthermore, it is a decision guide to support microalgal technologies.