The companies listed in Seine-Maritime are primarily IT services and software development firms. These are mostly mid-sized companies, with headcounts ranging from 30 to 149 employees. They include Attineos Applications, a digital services company, and Artemys Normandie, which focuses on digital transformation. DEVOLIS offers cloud migration and collaborative tools, while FTEL specializes in web and mobile software development.
A notable pattern is the concentration of these companies in the Rouen metropolitan area. Many are headquartered in Rouen itself, such as Attineos Applications and ACE Service, or in nearby towns like Sotteville-l猫s-Rouen (TOSHIBA Centre Grand Ouest, Docaposte Agility) and Le Petit-Quevilly (DEVOLIS, REDLab).
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Attineos Applicationsattineos.com
Attineos is a unique digital services company, focusing on client and employee satisfaction through expertise, technology, growth, and support |
149 | |||
| 2 |
Artemys Normandie (groupe Artemys)groupeartemys.com
The company offers a range of digital transformation services, with a focus on infrastructure, Cloud, BI, cybersecurity, and IT project management |
135 | |||
| 3 |
TOSHIBA Centre Grand Ouesttoshibatec.fr
Innovative company offering cutting-edge solutions tailored to businesses of all sizes, focused on understanding and addressing client needs with proven or innovative technologies |
94 | |||
| 4 |
Attineos Infrastructuresattineos.com
Offers IT systems and network services, focusing on human capital to support, operate, and transform information systems for clients. |
75 | |||
| 5 |
DEVOLISdevolis.com
DEVOLIS is a certified Microsoft partner offering tailored solutions for cloud migration, collaborative tools, app development, Big Data integration, and intelligent bots |
49 | |||
| 6 |
Docaposte Agilitydocaposte-agility.fr
Consulting firm driving agile and digital transformation for businesses Specializing in productivity enhancement and change success through tailored solutions and expertise |
45 | |||
| 7 | 43 | ||||
| 8 | 42 | ||||
| 9 |
Enovea, votre partenaire logicielenovea.net
Develops digital projects like 3D configurators and ERP integration. Publishes software for real-time matching, data reconciliation, and connected object data analysis. |
42 | |||
| 10 |
OASIS Projetoasis-projet.com
Agency specializing in e-commerce site creation, offering e-business solutions, training, and support for online business growth and management. |
39 | |||
| 11 | 35 | ||||
| 12 |
Actemium Le Havre Process Controlactemium.fr
Specializing in project management, automation, and industrial IT solutions, we enhance efficiency for industrial partners through process expertise and custom software solutions |
34 | |||
| 13 |
BearStudiobearstudio.fr
The BearStudio offers R&D support for innovative digital projects, from MVP design to technology implementation, with a hands-on approach in website, web app, and mobile app development |
33 | |||
| 14 |
Groupe FrameIPgroupe-frameip.fr
A group of IT companies specializing in enterprise networks, telecommunications, system infrastructure, and cybersecurity for professional clientele |
33 | |||
| 15 |
ACE Serviceattineos.com
Established in 2001, this company specializes in information systems security, with a focus on proactive monitoring and technological innovation for clients |
30 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 |
DIGITgroupedigit.com
Providing software development, system interoperability, data valorization, cost control, encryption, and IT team reinforcement with a focus on responsible digital practices. |
29 | |||
| 17 |
Caux Formatiquecauxformatique.fr
Specialized in management software, providing implementation, training, and support services for accounting, sales, payroll systems to professional clients Also offers IT maintenance |
27 | |||
| 18 |
ASSIST EVOLUTIONassist-evolution.com
A consultancy specializing in management and information systems, fostering strong partnerships with clients to enhance organizational efficiency |
26 | |||
| 19 |
Human to Computerhumantocomputer.com
Specializing in creating personalized and growth-driven web solutions since 2006 Services include website creation/redesign, web design, development, and e-marketing, emphasizing collaborative project methods |
25 | |||
| 20 |
Henosishenosis.fr
Henosis provides consulting, project management, and technical support services for large corporate clients in Normandy and the Paris region, focusing on IT infrastructure |
24 | |||
| 21 |
Fine Techfine-tech.fr
Fine Tech offers accompaniment services for cloud migration, Sage 100c management products, GDPR compliance analysis, and document management with a focus on innovative solutions for client satisfaction |
23 | |||
| 22 |
SIQUAL Informatiquesiqual.fr
Specializing in web solutions and information systems management, this company serves small businesses to large industrial groups with a focus on agility and client proximity |
22 | |||
| 23 |
ADMI France devient Bluebt-blue.com
Specializing in IT maintenance, cloud computing, telecoms, and system redesign, experts provide advice and technical know-how for seamless information management |
22 | |||
| 24 |
SIXMONsixmon.net
SIXMON specializes in developing complex web and mobile platforms, focusing on quality, scalability, and performance, with a passion for technology |
22 | |||
| 25 |
Artemys Agil-IT (groupe Artemys)groupeartemys.com
Support large enterprises with IT infrastructure, cloud, DevOps, user experience, BI, security, and training across multiple French regions and Belgium. |
20 | |||
| 26 |
Ceriel - Solutions d'infrastructure & Services ITceriel.fr
A digital services company based in Rouen, Le Havre, and Caen since 1990, providing expertise in IT infrastructure and services to drive growth and competitiveness |
18 | |||
| 27 |
FrameIPframeip.fr
FrameIP offers expertise in networking, security, telephony, and more, providing tailored solutions for infrastructure projects and professional training programs |
16 | |||
| 28 |
DEAPDATAdeapdata.com
A consulting firm specializing in business intelligence & big data, assisting clients with data management, visualization, analysis, science, and engineering projects Serving diverse industries |
14 | |||
| 29 |
wcomplywcomply.com
Provides specialized advisory services for cybersecurity, risk, and compliance, focusing on SAP system protection, cloud migrations, identity management, and financial license optimization. |
13 | |||
| 30 |
KEYVEOkeyveo.com
Specializing in virtual tours and immersive technologies, the company creates innovative digital projects for businesses, educational institutions, and municipalities with prestigious clients worldwide |
13 | |||
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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 11, 2026.
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The same list elsewhere in France
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