Jonathan Lascaux, co-founder and CEO of FiveForty
Mag author · Op-eds

Jonathan Lascaux

Co-founder and CEO of FiveForty

Jonathan Lascaux is the co-founder and CEO of FiveForty, a Microsoft Dynamics 365 Finance & Operations partner based in Paris with a presence in New York. He founded the company with Catherine Guibert.

With over 15 years of experience and more than 100 ERP projects, he helps companies implement and stabilise Dynamics 365 Finance & Operations.

His topics

ERP maintenance and support

Running maintenance beyond the ticket count: vendor updates, workarounds, configuration debt.

ERP project recovery

Spotting the signs of a project going off track and bringing it back without rebuilding everything.

Choosing and scoping a Dynamics 365 project

Scoping, choosing a partner, Business Central or Finance & Operations.

E-invoicing

Getting Dynamics 365 Finance & Operations ready for the French reform, and catching up.

In the press

IT SocialOp-ed · October 22, 2026

Maintenance d'ERP : ce que le compteur de tickets ne mesure pas (in French)

Maintenance contracts are managed on ticket counts and resolution times. Jonathan Lascaux shows what those indicators leave out, vendor-imposed updates and piling workarounds, and suggests two questions to ask your maintenance team.

Read on IT Social