Company lists · Data refreshed September 2026

Top 25 Legacy system modernization based in France

Name: Legacy system modernization based in France
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 20, 2026 679 companies tracked

RevenueBase identified 679 legacy system modernization headquartered in France as of September 2026 and tracks 8,501 professional contacts across them, including 3,305 with verified work emails. Paris is the largest hub.

This list covers legacy system modernization headquartered in France, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 20, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review

679Companies

8,501Contacts tracked

3,305Verified emails

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The 25 largest legacy system modernization based in France

Ranked by team size

Top 25 of 679 legacy system modernization based in France, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to legacy system modernization: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Acensi	Indirect evidence	Courbevoie, FranceHQ checked Sep 20, 2026	1,001-5,000	844 contacts →
	Indirect evidence “You will be part of ACENSI network: 1650 co-workers involved in IS transformation projects at our clients through our multisectoral expertise.” Source: RevenueBase Database · checked Sep 20, 2026
2	DCS Easyware	Indirect evidence	Lyon, FranceHQ checked Sep 20, 2026	1,001-5,000	532 contacts →
	Indirect evidence “Filiale du Groupe SYNERGIE, DCS SYNERGIE GROUP capitalise sur son histoire pour accompagner chaque jour les enjeux IT de ses clients.” Source: RevenueBase Database · checked Sep 20, 2026
3	ITS Group S.A	Indirect evidence	Boulogne-billancourt, FranceHQ checked Sep 20, 2026	1,001-5,000	342 contacts →
	Indirect evidence “For over 20 years, ITS Group has supported companies in their digital transformation projects thanks to the strength of its specialized areas of expertise.” Source: RevenueBase Database · checked Sep 20, 2026
4	Cyllene	Indirect evidence	Paris, FranceHQ checked Sep 20, 2026	201-500	279 contacts →
	Indirect evidence “Chez Cyllene, on couvre le spectre complet de votre besoin en termes de : Conseils 🧬 Définition d’architectures Hébergement & Services managés Cybersécurité & Formations…” Source: RevenueBase Database · checked Sep 20, 2026
5	Acelys Services Numériques	Indirect evidence	Montpellier, FranceHQ checked Sep 20, 2026	51-200	169 contacts →
	Indirect evidence “Créée en 1997, Acelys Services Numériques est une entreprise de services numériques (ESN) basée en Occitanie.” Source: RevenueBase Database · checked Sep 20, 2026
6	RBI	Indirect evidence	Rennes, FranceHQ checked Sep 20, 2026	11-50	133 contacts →
	Indirect evidence “Dans un monde où tout s’accélère, la transformation numérique n’est plus une option : c’est un levier de compétitivité.” Source: RevenueBase Database · checked Sep 20, 2026
7	Labsoft	Indirect evidence	Labège, FranceHQ checked Sep 20, 2026	51-200	132 contacts →
	Indirect evidence “Labsoft SSII accompagne des grands comptes régionaux et national ainsi que des PME PMI.” Source: RevenueBase Database · checked Sep 20, 2026
8	ENGIT	Indirect evidence	Valbonne, FranceHQ checked Sep 20, 2026	51-200	102 contacts →
	Indirect evidence “engIT \| Innovation IT & Transformation digitale - Faire du conseil différemment Depuis 2017, engIT accompagne les entreprises dans leurs projets stratégiques d'innovation…” Source: RevenueBase Database · checked Sep 20, 2026
9	Novahé	Partial evidence	Saint Cloud Cedex, FranceHQ checked Sep 20, 2026	51-200	92 contacts →
	Partial evidence “En 2018, AS-PC, EVEA TECHNOLOGY et INETD CONSULTING deviennent NOVAHE < Novahé accompagne les ETIs et les Grands Comptes dans l’optimisation et l’urbanisation de leur Système…” Source: RevenueBase Database · checked Sep 20, 2026
10	Digitalcook	Indirect evidence	Paris, FranceHQ checked Sep 20, 2026	51-200	86 contacts →
	Indirect evidence “DigitalCook #Weinspirechange Depuis 2016, DigitalCook accompagne les entreprises dans leurs projets de transformation digitale, infogérance, hardware & software, et cybesécurité.” Source: RevenueBase Database · checked Sep 20, 2026
11	Isitix	Indirect evidence	FranceHQ checked Sep 20, 2026	n/a	83 contacts →
	Indirect evidence “Depuis 20 ans, Isitix accompagne vos projets informatiques et numériques.” Source: RevenueBase Database · checked Sep 20, 2026
12	Hara Consulting	Indirect evidence	Strasbourg, FranceHQ checked Sep 20, 2026	51-200	81 contacts →
	Indirect evidence “HARA Consulting est un groupe spécialisé dans la transformation numérique des entreprises par la mise en place d'outils IA, data et tech.+ 1⃣ 0⃣ 0⃣ Collaborateurs - Experts…” Source: RevenueBase Database · checked Sep 20, 2026
13	Vaganet	Indirect evidence	Velizy-villacoublay, FranceHQ checked Sep 20, 2026	51-200	79 contacts →
	Indirect evidence “Pionnier du delivery agile depuis 2014, VAGANET met à disposition de ses clients des expertises techniques et fonctionnelles spécialisées dans la transformation et l’actualisation…” Source: RevenueBase Database · checked Sep 20, 2026
14	Attineos Infrastructures	Partial evidence	Mont-saint-aignan, FranceHQ checked Sep 20, 2026	51-200	69 contacts →
	Partial evidence “Attineos Infrastructures est une jeune ESN, spécialisée dans les Systèmes & Réseaux informatiques.” Source: RevenueBase Database · checked Sep 20, 2026
15	Tsplus Group	Indirect evidence	Paris, FranceHQ checked Sep 20, 2026	51-200	66 contacts →
	Indirect evidence “As businesses of all kinds become digital, organizations depend on the ability to create new disruptive business models, new ways to engage employees and customers, and new ways…” Source: RevenueBase Database · checked Sep 20, 2026
16	Komposite	Indirect evidence	Levallois-perret, FranceHQ checked Sep 20, 2026	11-50	63 contacts →
	Indirect evidence “Partenaire de la transformation digitale des entreprises, Komposite est l’architecte de la modernisation des infrastructures IT, fournisseur de services Cloud hybrides, et expert…” Source: RevenueBase Database · checked Sep 20, 2026
17	FOKUS	Indirect evidence	Lyon, FranceHQ checked Sep 20, 2026	51-200	61 contacts →
	Indirect evidence “FOKUS, où l’Humain et la Technologie se rencontrent.” Source: RevenueBase Database · checked Sep 20, 2026
18	Inforsud Technologies	Partial evidence	Bozouls (rodez), FranceHQ checked Sep 20, 2026	51-200	60 contacts →
	Partial evidence “Prestataire de services informatiques, nous accompagnons nos clients PME, ETI, Collectivités à gérer, sécuriser et transformer leur Système d’Information depuis plus de 35 ans.” Source: RevenueBase Database · checked Sep 20, 2026
19	Artik Consulting	Indirect evidence	Issy-les-moulineaux, FranceHQ checked Sep 20, 2026	11-50	59 contacts →
	Indirect evidence “Artik Consulting Artik est une société de conseil technologique qui accompagne les grandes entreprises dans leurs projets de transformation SI.” Source: RevenueBase Database · checked Sep 20, 2026
20	Kern Consulting	Partial evidence	Paris, FranceHQ checked Sep 20, 2026	51-200	59 contacts →
	Partial evidence “Kern Consulting est un cabinet d'experts spécialistes de la transformation de l'entreprise, convaincus que le Système d'Information en est un levier incontournable.” Source: RevenueBase Database · checked Sep 20, 2026
21	Arketeam	Partial evidence	Vandoeuvre Les Nancy, FranceHQ checked Sep 20, 2026	51-200	57 contacts →
	Partial evidence “Créée en 2008, ARKETEAM est à la fois un éditeur de logiciels, un cabinet de conseil et de service spécialisé dans les systèmes d'information.” Source: RevenueBase Database · checked Sep 20, 2026
22	IT Systemes	Indirect evidence	Malakoff, FranceHQ checked Sep 20, 2026	11-50	52 contacts →
	Indirect evidence “Votre logiciel métier devrait vous appartenir.” Source: RevenueBase Database · checked Sep 20, 2026
23	Onefirst	Partial evidence	Puteaux, FranceHQ checked Sep 20, 2026	51-200	49 contacts →
	Partial evidence “Onefirst Group is a Consultancy specialising in Information Systems Management and Digital Transformation.” Source: RevenueBase Database · checked Sep 20, 2026
24	CONIX	Partial evidence	Paris, FranceHQ checked Sep 20, 2026	51-200	49 contacts →
	Partial evidence “Conix Technologies et Services est une ESN, filiale de Conix Services créée en 1997, dédiée à la réalisation et à la sécurisation du Système d’Information de l’entreprise étendue.” Source: RevenueBase Database · checked Sep 20, 2026
25	Atémis	Indirect evidence	La Chapelle Sur Erdre, FranceHQ checked Sep 20, 2026	11-50	49 contacts →
	Indirect evidence “Depuis plus de 25 ans, ATÉMIS accompagne les entreprises dans la conception, le déploiement et la sécurisation de leurs infrastructures informatiques.” Source: RevenueBase Database · checked Sep 20, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: legacy system modernization. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names legacy system modernization.
Partial evidence: Its own public description names part of legacy system modernization, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name legacy system modernization. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 679 legacy system modernization based in France

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Legacy system modernization based in France at a glance

As of Sep 20, 2026

38.9%Verified-email coverage

12.5Average contacts per company

1-10Median size (employees)

20.8%Largest-city concentration · Paris

Sep 20, 2026Page data refreshed

Companies by employee count

1-10

417

11-50

202

51-200

201-500

1,001-5,000

Email recency for this list is measured worldwide rather than for France, so it is reported there. Company counts and contact totals on this page are exact for France, over 679 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among legacy system modernization, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in France whose own description of what they do matches “legacy system modernization”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names legacy system modernization), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among legacy system modernization, and records with no verified work email. Companies headquartered outside France are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 3,305 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 20, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Legacy system modernization by metro

Legacy system modernization in Paris141
Legacy system modernization in Lyon25

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names legacy system modernization, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many legacy system modernization are there based in France?

RevenueBase identified 679 legacy system modernization headquartered in France as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Acensi, headquartered in Courbevoie, tops this list with the largest team on record.

Which city has the most legacy system modernization?

Paris leads with 141 headquartered companies, followed by Lyon (25) and Toulouse (15).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 3,305 verified decision-maker contacts tracked across these 679 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 20, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.