Christophe Lachnitt
Instructor
Sorbonne Université Formation Continue
Christophe Lachnitt teaches Generative Engine Optimization in Sorbonne Université's continuing-education program with CELSA, and advises communications leaders through his consultancy Croisens. After two decades leading communications and marketing in large groups, he now helps organizations rethink strategy, organization, and generative AI together.
Communications at Alcatel and Beyond
Lachnitt spent about twenty years as a communications and/or marketing director in large groups. Public materials credit him with serving as Alcatel spokesperson during a strategy crisis and share-price plunge, helping position the company around Internet networks after the dot-com bubble, leading a major Microsoft France marketing plan and image turnaround, and rebuilding Naval Group internal communications plus a corporate social responsibility program recognized by the French Senate.
He was a member of executive committees of multibillion-dollar businesses for thirteen years.
A Climbing Accident and Croisens
In 2014-2015 a near-fatal rock-climbing accident led to spinal bone-graft surgery, a year bedridden, and months of inpatient rehabilitation; he has official disability status for employment purposes and has also survived cardiac arrests. Those experiences appear in a TEDx talk on how near-death changed his relationship with life, and they mark the reset after which he founded Croisens.
Croisens helps communications functions transform through a flywheel of strategy, organization, and generative AI. He also founded Superception (blog, newsletter, podcast) on perception, has published thousands of articles there, and is the author of four books, three on the digital revolution and one on how professional climbers manage fear.
Teaching GEO at Sorbonne and CELSA
Sorbonne's GEO continuing-education program, organized with CELSA, is a two-day professional course on AI-search visibility mechanisms, producing content generative engines can cite, and strengthening organizational visibility, authority, and reputation. Lachnitt is listed among the instructors for that Formation Continue offer and is also a guest lecturer at CELSA and Sciences Po Paris.
His consulting client list spans large French and international organizations across energy, finance, industry, and the public sector.
Communications in the Age of AI
Lachnitt's public thesis is that communications teams have to balance audience fragmentation with brand development while generative AI changes how organizations are described.