Fabrice Drouin appears in the French company register among the officers of ACINQ, the Paris company created in August 2014. His GitHub profile, under the handle sstone, gives his affiliation as ACINQ in Paris.
His work is on Eclair, the Apache 2.0 licensed Scala implementation of the Lightning Network that ACINQ maintains. The repository dates from August 2015, which puts it among the earliest Lightning codebases, and the project follows the BOLT specifications rather than defining its own protocol. That distinction matters for how his work should be read: implementation and specification are separate activities, and Eclair's value to the network comes from being an independent codebase that other implementations can be tested against.
Only his public professional role and published work are recorded here.