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Interactive Query Creation Tool


A web application that allows to formulate complex queries against big databases. The query concepts are drag-and-dropped to form logical connections. Results can be further restricted by filters and date range.


How would you compose queries against a database in a visual, interactive way? What if all parts of the query are available as "concepts", organized in a tree structure? The team at bakdata asked me to build a hand-tailored single page web app, which would rely heavily on drag and drop to compose queries and to execute them against an API backend.


Introducing: conquery. Using conquery, item trees can be explored, similar to your file system. The so called "concepts" in the tree vary in their degree of abstraction. This allows a user to ask queries in a very abstract manner, but also in great detail. To build a query, the concepts are dropped into a query editor, using AND/OR-connections. Results can be downloaded as a CSV file.

My role

Over the course of 9 months, I worked part-time on the UX and React frontend, while my colleague Manuel crafted the Java backend. The clear responsibilities allowed us to move quickly in terms of functionality. After starting to work full-time at neXenio, bakdata hired three developers who continued improving the web app. Built for a great client at first, bakdata recently even managed to open source the frontend code!