Francesco Tosoni

I'm a computer science researcher and a Wikimedian passionate about making open data more efficient, accessible, and sustainable. My work sits at the intersection of lossless compression algorithms, open data infrastructures, and green computing.

By day, at Sant'Anna School of Advanced Studies I research compressed data structures, indexing and retrieval techniques for the Software Heritage archive, the "Library of Alexandria" of code. By weekends, I keep contributing to open-data, collaborative projects like Wikidata.

My core research area is lossless compression. I completed my PhD at the University of Pisa under the supervision of Professors P. Ferragina and G. Manzini, focusing on computation-friendly compression: techniques that allow us to operate directly on compressed data without decompression overhead. The challenge is to develop tools that make data processing more energy-efficient, too. Compression is not just about saving space on disk: the real challenge is to adapt compression schemes so that they allow to operate directly in main memory (without compression overhead) and in time proportional to the compressed representation size.

As an algorithmist, I primarily specialised in lossless data compression. Since July 2024, I have been working on optimising the compression and efficient indexing of large code archives in collaboration with the Software Heritage team.