These large IT services companies in Loire-Atlantique provide a range of digital transformation, consulting, and software development services. Companies like Experis France support DSI with innovative digital transformation projects, while Catamania offers digital transformation services, consulting, and software publishing. Groupe Sigma aims to enhance performance through digital impact, and ASI庐 focuses on a responsible digital world. U IRIS devient U TECH manages the IT system for Groupement U, and Conserto provides IT consulting across cloud, digital, and embedded domains.
The companies listed here are primarily established mid-sized to large firms, with a concentration of headquarters in Saint-Herblain. Many were founded in the late 1990s and early 2000s, indicating a mature and well-developed IT sector in the region, focusing on diverse technical expertise and comprehensive digital solutions for various sectors.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Experis Franceexperisfrance.fr
Supports DSI with innovative digital transformation projects, providing IT services and talent solutions to enhance organizational performance, addressing specific needs. |
2,207 | |||
| 2 |
Catamaniacatamania.com
Provides digital transformation services, consulting, software publishing, and information system architecture for banking, insurance, and retail sectors across international agencies using diverse technical expertise. |
797 | |||
| 3 |
U IRIS devient U TECHu-emploi.com
Management and innovation of the entire Groupement U IT system, supporting retail, supply chain, and digital transformation projects. |
637 | |||
| 4 |
Groupe Sigmasigma.fr
The company aims to enhance performance through digital impact, innovate eco-friendly solutions, and build digital ecosystems with expert dialogue |
607 | |||
| 5 | 590 | ||||
| 6 |
Consertoconserto.pro
Offers IT consulting and expertise services across cloud, digital, and embedded domains through consulting, delivery centers, and labs models. |
555 | |||
| 7 |
4CAD Group4cadgroup.com
The company offers PLM, ERP, and IoT tools to help organizations optimize their information systems for increased industrial efficiency |
463 | |||
| 8 |
AISgroupeais.fr
AIS is a human-centric company providing expertise to clients since 1985, focusing on professional growth and fulfillment of its employees |
289 | |||
| 9 | 224 | ||||
| 10 |
GROUPE SYDsyd.fr
Specializing in digital transformation, the company offers consultancy, project management, infrastructure services, Microsoft solutions integration, application development, and Microsoft expertise, emphasizing customer satisfaction and trust |
190 | |||
| 11 |
Dynamipsdynamips.com
A pioneer in professional IT services, providing support to SMEs and Local Authorities across France Specializing in optimizing systems, data security, cloud solutions, and personalized IT services |
179 | |||
| 12 |
ORINOXorinox.com
Software consulting and plant design firm specializing in digitalization using AVEVA software suite for engineering, asset data visualization, resources management, simulation, and training |
166 | |||
| 13 |
VFLIT - Vous faciliter l'ITvousfaciliter-it.fr
Providing integrated cybersecurity, cloud, telecom, management applications, and safety services to enhance organizational IT and communication system performance. |
164 | |||
| 14 | 159 | ||||
| 15 |
Valeuriadvaleuriad.fr
Experts in transforming complex information systems, providing technical excellence in AI, data engineering, cloud, and infrastructure for large organizations. |
156 | |||
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| 16 |
Capaciticapaciti.com
A regional leader in cybersecurity, providing specialized services in consulting, engineering, and system infrastructure support with offices in France and international project capabilities |
150 | |||
| 17 |
KOSMOSkosmos-education.com
Specializing in digital education solutions, this company implements web portals, e-portfolios, mobile apps, and other digital tools for schools |
141 | |||
| 18 | 128 | ||||
| 19 | 118 | ||||
| 20 |
proLogistik France (DSIA)logistar-dsia.com
French subsidiary of a pan-European group, publishing, integrating, and hosting supply chain solutions, including WMS, OMS, LMS, TMS, ensuring optimal security and accessibility. |
114 | |||
| 21 |
Mismo Informatiquemismo.fr
A comprehensive IT solutions provider offering infrastructure, hardware, software, and services to streamline operations for 3,000 businesses, with certifications and partnerships with industry leaders |
113 | |||
| 22 | 92 | ||||
| 23 |
Le Pharelephare.com
Digital product factory for SMEs, ETIs, and industries Provides digital transformation consulting and custom platforms to accelerate B2B and B2B2C businesses |
87 | |||
| 24 |
Iliane Informatiqueiliane.fr
Providing comprehensive IT solutions for businesses of all sizes to effectively manage their information systems |
83 | |||
| 25 |
Mercuriamercuria.fr
Advises and supports businesses with SaaS, Cloud, or hosted solutions for accounting, financial, payroll, and HR management software, working with reliable publishers. |
82 | |||
| 26 |
mobiappsFrmobiapps.fr
mobiApps specializes in creating multiplatform mobile apps using emerging hybrid technologies like HTML/CSS and JavaScript, along with digital strategy services |
74 | |||
| 27 |
Voxalyvoxaly.com
Specialized in electronic voting systems, organizing elections for labor unions, supervisory boards, shareholder meetings for top French companies Customized solutions since 2006 |
73 | |||
| 28 |
ELEPHANT Technologieselephant-technologies.fr
Offers expert human-centered tech consultancy, ensuring perfect alignment between client needs and employee skills across various IT domains from idea to production. |
69 | |||
| 29 |
ABASEgeneration-net.org
ABASE 20 is a digital services company providing a variety of digital solutions and services to clients |
67 | |||
| 30 | 61 | ||||
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How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 12, 2026.
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