The Flexible Query Processor (FQP) constitutes a family of hardware-based data stream processors that support dynamic changes to queries and streams, as well as static changes to the processor-internal fabric in order to maximize performance for given workloads. FQP is prototyped on field-programmable gate arrays (FPGAs). To this end, FQP supports select, project and window-join queries over data streams. While processing incoming tuples, FQP can accept new queries, a key characteristic distinguishing FQP from related approaches employing FPGAs for stream processing. In this paper, we present our vision of FQP, focusing on few internal details to support the flexibility dimension, in particular, the segment-at-a-time mechanism to realize processing of tuples of variable sizes. While many of these features are readily available in software, their hardware-based realizations have been one of the main shortcomings of existing research efforts.