ADASS XXXI

Astronomical data are now accessible from a wide variety of online services. Astronomers can access many of these services programmatically (e.g. from Python) to unlock powerful new research outcomes. Aggregating heterogeneous observational data for one or several targets is a common task performed by astronomers that benefits substantially from the growing ecosystem of online services. We introduce Data Central's Data Aggregation Service (DAS), an interactive web application that leverages Aladin Lite to display images and catalogues resulting from multiple online service queries of a given target. The DAS is a high-performance technology demonstrator for modern asynchronous Python that enables fast, simultaneous execution of queries. Query results may also be directed to a Pipeline As a Web Service (PAWS), whereby a data reduction pipeline is executed in the background and the results displayed upon completion. Examples include on-demand mosaic production for the SkyMapper Southern Sky Survey and archival ESO FORS2 and Gemini GMOS images. We conclude with an overview of future plans, focusing on user customisation of DAS and adapting DAS to cater for large target catalogues. We anticipate that services like DAS will play an essential role in simplifying access to the massive data volumes expected from next generation facilities.