# The 30 largest professional services firms in the Val-d'Oise department
Tamtam tracks 44 professional services firms headquartered in the Val-d'Oise department. This list ranks the 30 largest by number of employees on LinkedIn, led by Chubb Fire & Security France, Worldgrid and SERIMAX. Their median headcount is 43. Half of them were founded in 2002 or later. The most common headquarters are Bezons (6), Roissy-en-France (5) and Cergy (4).
The Val-d'Oise department hosts a concentration of professional services firms, ranging from IT and security to industrial manufacturing and aviation. These companies include both established mid-sized firms and younger enterprises. Many specialize in niche technical services, catering to business clients.
Among them, Chubb Fire & Security France provides fire and electronic security solutions. Worldgrid specializes in smart energy solutions for utilities, while SERIMAX is a global leader in pipeline welding. JRI develops temperature monitoring solutions for healthcare and industry, and Simaero offers pilot training and simulation engineering.
馃嚝馃嚪 Val-d'Oise 路 30 companies 路 Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Chubb Fire & Security France](https://www.tamtam.ai/c/chubb-fire-and-security-france) (chubbfs.com)
Fire and electronic security solutions provider. Installation, maintenance of detection, extinction, access control, video surveillance systems, and remote monitoring for businesses and individuals. | Security and Investigations | 馃嚝馃嚪 Cergy | 1,661 | |
| 2 | [Worldgrid](https://www.tamtam.ai/c/worldgrid) (alten.com)
Specializing in smart energy solutions for utilities, we offer integration projects and real-time solutions across the power, water, oil & gas sectors | IT Services and IT Consulting | 馃嚝馃嚪 Bezons | 970 | 2009 |
| 3 | [SERIMAX](https://www.tamtam.ai/c/serimax) (serimax.com)
Global leader in pipeline welding solutions, offering high quality automatic and manual welding services on land and sea, in tough conditions Specializes in innovative equipment | Industrial Machinery Manufacturing | 馃嚝馃嚪 Roissy-en-France | 748 | 1978 |
| 4 | [JRI](https://www.tamtam.ai/c/jri) (jri-mms.com)
Develops temperature monitoring solutions for thermo-sensitive products in healthcare, food, and industry, utilizing IoT technology and offering metrology services. | Measuring and Control Instrument Manufacturing | 馃嚝馃嚪 Bezons | 298 | 1845 |
| 5 | [Simaero](https://www.tamtam.ai/c/simaero) (sim.aero)
Global provider of pilot training on full-flight simulators and simulation engineering solutions for international airlines and pilots. | Airlines and Aviation | 馃嚝馃嚪 Roissy-en-France | 199 | 2002 |
| 6 | [Edifixio](https://www.tamtam.ai/c/edifixio) (edifixio.com)
Provides IT services to large international companies, specializing in Industry, Retail, Insurance, and Services sectors, with a global presence. | IT Services and IT Consulting | 馃嚝馃嚪 Bezons | 192 | 2000 |
| 7 | [CONSUL'TECH](https://www.tamtam.ai/c/consul-tech)
Founded in 2008, the company specializes in technical engineering, construction, project management, maintenance engineering, and technical management support for real estate professionals | Real Estate | 馃嚝馃嚪 Bezons | 124 | 2008 |
| 8 | [H-Tech Supports](https://www.tamtam.ai/c/h-tech-supports) (htechsupports.com)
Provides modern IT and network solutions, offering managed IT support, professional consulting, data solutions, and maintenance services to enterprise markets worldwide. | IT Services and IT Consulting | 馃嚝馃嚪 Saint-Leu-la-For锚t | 107 | 2016 |
| 9 | [ESE脧S](https://www.tamtam.ai/c/eseis) (eseis.fr)
Provides facility management services including workspace management, maintenance, general services, and innovative digital solutions to enhance operational efficiency. | Business Consulting and Services | 馃嚝馃嚪 Bezons | 96 | 2000 |
| 10 | [SPIE Operations](https://www.tamtam.ai/c/spie-operations) (spie.com)
Provides multi-technical services in energy and communications sectors, supporting energy transition and digital transformation with diverse, committed teams. | IT Services and IT Consulting | 馃嚝馃嚪 Cergy | 70 | |
| 11 | [BeGC](https://www.tamtam.ai/c/begc) (fr.begc-groupe.com)
Engineering & design office specializing in mechanical engineering, machines design, automation, and safety audits for various industries worldwide since 1981 | Industrial Machinery Manufacturing | 馃嚝馃嚪 Goussainville | 60 | 1981 |
| 12 | [IMP360](https://www.tamtam.ai/c/imp360) (imp-360.com)
Specialist in healthcare IT providing security evaluation, system integration, infrastructure management, medical imaging solutions, and continuity planning for clients. | IT Services and IT Consulting | 馃嚝馃嚪 Roissy-en-France | 54 | 1997 |
| 13 | [Time to Fly](https://www.tamtam.ai/c/time-to-fly) (timetofly.eu)
Consulting company specializing in aeronautics founded by an experienced airline manager Services include aviation operation, engineering, maintenance, safety, and airport consulting worldwide | Airlines and Aviation | 馃嚝馃嚪 Roissy-en-France | 53 | 2009 |
| 14 | [STEPHYA](https://www.tamtam.ai/c/stephya) (stephya.com)
STEPHYA is a DATACENTER service center in France, offering IT relocation services across Europe with experienced consultants and highly skilled technicians | IT Services and IT Consulting | 馃嚝馃嚪 Montmorency | 50 | 1999 |
| 15 | [Snapcom](https://www.tamtam.ai/c/snapcom) (snapcom.eu)
Specializes in consulting, deploying, and optimizing unified communications, videoconferencing, audiovisual, and event solutions with expert services and training. | IT Services and IT Consulting | 馃嚝馃嚪 Bezons | 43 | 2005 |
| 16 | [Negociatis](https://www.tamtam.ai/c/negociatis) (negociatis.com)
Support companies of all sizes in their commercial development through expertise in national and international B2B sales of products and services. | Business Consulting and Services | 馃嚝馃嚪 Eaubonne | 37 | 2007 |
| 17 | [INFODIP](https://www.tamtam.ai/c/infodip) (infodip.com)
A European IT company with 35 years' experience, offering customized solutions, appliances, service delivery, and support adhering to ISO 9001 standards | IT Services and IT Consulting | 馃嚝馃嚪 Saint-Leu-la-For锚t | 35 | 1986 |
| 18 | [Techma](https://www.tamtam.ai/c/techma) (techmadev.com)
Provider of services, turnkey supply, and technical assistance for industrial process control, automation, instrumentation, safety, SCADA, and telecoms for over 25 years | IT Services and IT Consulting | 馃嚝馃嚪 Cergy | 33 | 1994 |
| 19 | [MIDRANGE Group](https://www.tamtam.ai/c/midrange-group) (midrange-group.com)
Provides innovative, tailor-made digital services like IT support, AI, data, and IT asset disposition, focusing on sustainability and local economic commitment for businesses. | IT Services and IT Consulting | 馃嚝馃嚪 Saint-Ouen-l'Aum么ne | 28 | 1993 |
| 20 | [Skills & Affinity](https://www.tamtam.ai/c/skills-and-affinity) (skillsaffinity.com)
Skills & Affinity is an innovative recruitment solution focusing on human connection, matching talents with companies based on projects and skills | Staffing and Recruiting | 馃嚝馃嚪 Vaur茅al | 26 | 2018 |
| 21 | [Dao-Infranet](https://www.tamtam.ai/c/dao-infranet) (dao-infranet.com)
A specialized engineering firm offering VRD studies, topography, and network detection services with experienced team, advanced equipment, and high client satisfaction | Engineering Services | 馃嚝馃嚪 Cergy | 23 | 2011 |
| 22 | [Comme Une Image](https://www.tamtam.ai/c/comme-une-image) (commeuneimage.fr)
A communication agency offering graphic design, editorial expertise, event planning, PR, and digital strategies to help businesses stand out authentically | Advertising Services | 馃嚝馃嚪 Arnouville | 23 | 1992 |
| 23 | [INCUB'ETHIC](https://www.tamtam.ai/c/incub-ethic) (incubethic.fr)
Consulting firm specializing in sustainable development, CSR, energy eco-efficiency, multiservice solutions, and ethical investment with human-centered leadership. | Environmental Services | 馃嚝馃嚪 Cormeilles-en-Parisis | 22 | 2009 |
| 24 | [Apave Parisienne Osny](https://www.tamtam.ai/c/apave-parisienne-osny)
This company offers comprehensive services in training, inspections, building, testing, consulting, and certification to help businesses and municipalities manage technical, human, and environmental risks | Security & Investigations | 馃嚝馃嚪 Osny | 21 | 1867 |
| 25 | [RH'Venture](https://www.tamtam.ai/c/rh-venture) (rhventure.fr)
Supports small and medium-sized businesses in structuring their HR function and ensuring the success of their HRIS projects, providing temporary HR and HRIS reinforcement. | Human Resources Services | 馃嚝馃嚪 Sannois | 20 | 2021 |
| 26 | [IT-tude](https://www.tamtam.ai/c/it-tude) (it-tude.fr)
IT-tude by Infodis is a consulting and integration company specializing in IT Service Management, Enterprise Service Management, and IT Asset Management solutions | IT Services and IT Consulting | 馃嚝馃嚪 Roissy-en-France | 16 | 2014 |
| 27 | [EXTO SAS](https://www.tamtam.ai/c/exto-sas) (exto.fr)
Provides IT management consulting services, including software implementation, training, technical support, custom development, and IT infrastructure and security management for businesses. | Software Development | 馃嚝馃嚪 Goussainville | 14 | 1995 |
| 28 | [INSIDE AMO CONCEPT](https://www.tamtam.ai/c/inside-amo-concept) (inside-ac.com)
Inside offers services in project management, technical control, and consulting for real estate assets in various sectors such as commercial, residential, and office spaces | Real Estate | 馃嚝馃嚪 Argenteuil | 13 | 2015 |
| 29 | [EXPORTECH](https://www.tamtam.ai/c/exportech) (exportech.eu)
Exportech helps small businesses in electronics, plastics, and metallurgy sectors achieve practical results in their export projects with a specialized, multilingual team | International Trade & Development | 馃嚝馃嚪 Neuville-sur-Oise | 13 | 2003 |
| 30 | [JM MATEU, A SANCHEZ & JC TASSEL NOTAIRES ASSOCIES](https://www.tamtam.ai/c/jm-mateu-a-sanchez-and-jc-tassel-notaires-associes) (magma.notaires.fr)
A team of 8 notaries and 30 staff members operating in two locations, specializing in legal services in Magny en Vexin and Mantes la Jolie | Legal Services | 馃嚝馃嚪 Magny-en-Vexin | 13 | 1630 |
## 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 11, 2026.
## More company lists in the Val-d'Oise department
- [The largest companies in the Val-d'Oise department](https://www.tamtam.ai/l/largest-companies-val-doise) (849)
- [Multinational companies in the Val-d'Oise department](https://www.tamtam.ai/l/multinational-companies-val-doise) (128)
- [Companies with in-house R&D in the Val-d'Oise department](https://www.tamtam.ai/l/r-and-d-companies-val-doise) (88)
- [Manufacturers in the Val-d'Oise department](https://www.tamtam.ai/l/manufacturers-val-doise) (85)
- [Hardware manufacturers in the Val-d'Oise department](https://www.tamtam.ai/l/hardware-companies-val-doise) (70)
- [Distributors and wholesalers in the Val-d'Oise department](https://www.tamtam.ai/l/distributors-and-wholesalers-val-doise) (67)
- [Retail chains in the Val-d'Oise department](https://www.tamtam.ai/l/retail-chains-val-doise) (56)
- [Family-owned companies in the Val-d'Oise department](https://www.tamtam.ai/l/family-owned-companies-val-doise) (42)
- [IT services companies in the Val-d'Oise department](https://www.tamtam.ai/l/it-services-companies-val-doise) (42)
- [IT Services and IT Consulting companies in the Val-d'Oise department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-val-doise) (38)
- [Transportation, Logistics, Supply Chain and Storage companies in the Val-d'Oise department](https://www.tamtam.ai/l/transportation-logistics-supply-chain-and-storage-companies-val-doise) (33)
- [Aerospace and defence companies in the Val-d'Oise department](https://www.tamtam.ai/l/aerospace-and-defense-companies-val-doise) (31)
- [Public sector organisations in the Val-d'Oise department](https://www.tamtam.ai/l/public-sector-organisations-val-doise) (30)
- [Construction companies in the Val-d'Oise department](https://www.tamtam.ai/l/construction-companies-val-doise) (29)
- [Wholesale companies in the Val-d'Oise department](https://www.tamtam.ai/l/wholesale-companies-val-doise) (29)
- [Healthcare providers in the Val-d'Oise department](https://www.tamtam.ai/l/healthcare-providers-val-doise) (27)
- [Industrial Machinery Manufacturing companies in the Val-d'Oise department](https://www.tamtam.ai/l/industrial-machinery-manufacturing-companies-val-doise) (27)
- [Government Administration companies in the Val-d'Oise department](https://www.tamtam.ai/l/government-administration-companies-val-doise) (26)
- [Logistics companies in the Val-d'Oise department](https://www.tamtam.ai/l/logistics-companies-val-doise) (25)
## The same list elsewhere in France
- [Professional services firms in France](https://www.tamtam.ai/l/professional-services-firms-france) (6,611)
- [Professional services firms in 脦le-de-France](https://www.tamtam.ai/l/professional-services-firms-ile-de-france) (3,377)
- [Professional services firms in Auvergne-Rh么ne-Alpes](https://www.tamtam.ai/l/professional-services-firms-auvergne-rhone-alpes) (711)
- [Professional services firms in the Hauts-de-Seine department](https://www.tamtam.ai/l/professional-services-firms-hauts-de-seine) (629)
- [Professional services firms in Provence-Alpes-C么te d'Azur](https://www.tamtam.ai/l/professional-services-firms-provence-alpes-cote-dazur) (433)
- [Professional services firms in the Rh么ne department](https://www.tamtam.ai/l/professional-services-firms-rhone) (400)
- [Professional services firms in Occitanie](https://www.tamtam.ai/l/professional-services-firms-occitanie) (399)
- [Professional services firms in Grand Est](https://www.tamtam.ai/l/professional-services-firms-grand-est) (316)
- [Professional services firms in Nouvelle-Aquitaine](https://www.tamtam.ai/l/professional-services-firms-nouvelle-aquitaine) (308)
- [Professional services firms in Hauts-de-France](https://www.tamtam.ai/l/professional-services-firms-hauts-de-france) (260)
- [Professional services firms in Pays de la Loire](https://www.tamtam.ai/l/professional-services-firms-pays-de-la-loire) (254)
- [Professional services firms in the Bouches-du-Rh么ne department](https://www.tamtam.ai/l/professional-services-firms-bouches-du-rhone) (249)
- [Professional services firms in the Haute-Garonne department](https://www.tamtam.ai/l/professional-services-firms-haute-garonne) (208)
- [Professional services firms in the Nord department](https://www.tamtam.ai/l/professional-services-firms-nord) (178)
- [Professional services firms in Brittany](https://www.tamtam.ai/l/professional-services-firms-brittany) (167)
- [Professional services firms in the Loire-Atlantique department](https://www.tamtam.ai/l/professional-services-firms-loire-atlantique) (158)
- [Professional services firms in the Gironde department](https://www.tamtam.ai/l/professional-services-firms-gironde) (151)
- [Professional services firms in Normandy](https://www.tamtam.ai/l/professional-services-firms-normandy) (114)
- [Professional services firms in the Yvelines department](https://www.tamtam.ai/l/professional-services-firms-yvelines) (108)
- [Professional services firms in Paris](https://www.tamtam.ai/l/professional-services-firms-paris) (2,241)
- [Professional services firms in Lyon](https://www.tamtam.ai/l/professional-services-firms-lyon) (265)
- [Professional services firms in Toulouse](https://www.tamtam.ai/l/professional-services-firms-toulouse) (139)
- [Professional services firms in Marseille](https://www.tamtam.ai/l/professional-services-firms-marseille) (123)
- [Professional services firms in Boulogne-Billancourt](https://www.tamtam.ai/l/professional-services-firms-boulogne-billancourt) (102)
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Source: https://www.tamtam.ai/l/professional-services-firms-val-doise