Legacy blocks each new release
Every change now depends on workarounds, manual checks or risk trade-offs that have become permanent.
See our modernization approachREELIANT · Digital Engineering Workshop
Engineering trust — legacy IT modernization, digital trust and cybersecurity
Modernize. Build. Maintain. For the long run.
We modernize complex critical systems and embed digital trust from the architecture up. We step in when environments become hard to evolve, and we take responsibility for maintaining them in a trusted condition over time.
Top 1% EcoVadis Platinum
9 years Critical systems
40+ Regulated clients
100+ Projects delivered
When to call us
The situations where we can genuinely help
If you're in one of these situations, we should talk.
A regulatory deadline is getting close
eIDAS, KYC, signature, security or auditability must be built into the architecture without stalling delivery.
See our digital trust scopeA new service to launch — built to last from day one
From idea to production: architecture, compliance and AI integrated from the start so innovation holds.
See our build and AI offerRUN is eating your team capacity
Incidents may be limited, yet security, debt and compliance are moving without a clear operating model.
See our MCC offerCore territory
Our 3 intervention pillars
Information System Modernization
Your legacy assets must evolve without disruption.
Your legacy systems keep the business running, but technical debt slows your deployments. We modernize them from the inside, through controlled iterations, without interrupting the service.
View service →New Services, AI & Cyber
Innovation must not mean losing control.
Business services and AI: we build them to integrate securely into your existing architecture.
View service →Maintenance in Trusted Condition (MCC)
"It works" is no longer enough.
We don't just maintain your applications: we guarantee control over them over time. When the regulatory or security landscape changes, you've already anticipated it.
View service →Engagement models
We adapt to your starting point
01
Quick diagnostic
Frame fast and decide right
In a few weeks, we map risks, clarify the trajectory, and propose an executable plan.
02
Dedicated team
Design and deliver with accountability
A senior team equipped to build, modernize, and integrate without disrupting your operations.
03
Piloted MCC
Sustain reliability over time
RUN, security, quality, and compliance steered with explicit criteria and readable governance.
OUR STANDARD
Digital trust by design
Protect
Identity
Strong authentication, entitlement management and access control.
Security
Prevention, detection and response: from code to infrastructure.
Engage
Compliance
Regulatory framework treated as an architectural constraint.
Traceability
Signatures, commitments and transactions: tracked, timestamped and legally binding.
Our AI conviction
AI as a lever. Mastery as a condition.
AI experiments are multiplying. But deploying it in production in regulated environments is another matter.
In regulated environments, you don't plug an LLM in without authentication, traceability, and isolation in place first.
LLMOps, agents, workflow automation: we design for production, with the same security and auditability requirements as the rest of the system.
Production references
Critical systems delivered and maintained over time
A few recent examples in production.
Finance & Automotive Credit
Digital Subscription Platform - BMW Financial Services France
- 295 points of sale
- 300 files per day
- live since 2020
Implementation of a fully digital subscription solution - in dealership and remotely - for BMW Financial Services France (ACPR-regulated credit institution) and its network of 295 points of sale (BMW, MINI, Motorrad). Fully paperless journey for both customers and advisors. Scope: identity & authentication, E-KYC, electronic signature, probative archiving. Live since 2020.
- More than 300 files processed per day
- E-KYC, KYB and Open Banking: enriched data for better decisions
- Full integration with BMW business tools
Identity & Qualified Signature
jesignexpert.com e-signature platform for the accounting profession - ECMA
- 5M signatures in 2025
- 1.6M seals in 2025
- 60 partner integrations
Development and maintenance since 2018 of jesignexpert.com, an eIDAS-compliant electronic signature and sealing platform dedicated to the accounting profession. Covers three signature levels (simple, advanced with LCP nominal certificate, qualified via ANSSI-certified PVID) and supports multi-document, multi-signatory and multi-firm workflows.
- 5 million signatures and 1.6 million seals in 2025
- Electronic signatures from simple to advanced, with qualified certificate
- Integrated with 60 partners via dedicated APIs
- Interoperability with jedeclare.com and jefacture.com
- Gold medal Monde du Chiffre 2025 (7th consecutive year)
Energy & Professional Networks
New Extranet and consumer matchmaking platform - Les Professionnels du Gaz
- 10,600 certified companies
- business tools + e-learning
- real-time lead distribution
Design and development of the new information system for habitA+, which manages the PG quality programme (Professionnels du Gaz) for 15+ years. Members include GRDF, ENGIE, EDF, Butagaz, Antargaz and emerging biomethane players.
- Support for 10,600 certified PG companies
- Business tools: maintenance certificates, Visa Qualité sheet, correspondence tracking, compliance audits and project monitoring
- Level assessment and integrated e-learning modules for professionals
- Commercial matching: offers published, ranked and tracked in real time
- Duty-of-care traceability: every intervention documented and legally enforceable
Water & Public Services
Online Web & Mobile Agency - Veolia Eau
- 1M+ active users
- 15 local brand apps
- 4.5/5 store rating
Co-design, development and operation of Veolia Eau's online Web and Mobile agencies. The web online agency combines a showcase site and customer area, rolled out across local brands. Platform integrated with core business systems and continuously maintained.
- National app: 1M+ active users, rated 4.5/5 on app stores
- 15 local brand apps published and maintained on the stores
- Shared CMS (content management system): each brand publishes content locally or nationally
Our final validation test is simple: would we be proud to use this tool ourselves? If the answer is no, we don't ship it.
Our basecamp
Paris 9th, between Opéra and Saint-Lazare
Our teams work on-site and our clients visit regularly. It makes collaboration straightforward.
10 rue Auber, 75009 Paris View on Google MapsJoin the Workshop
We build systems that last.
We recruit engineers who own the full lifecycle: design, development, production, operational maintenance.
- Growth through real-world experience, not slides
- Genuine architecture and security challenges, not simulations
- Every line of code written to last ten years
A demanding but rare environment: one where your work has a real and lasting impact.
Join us →
OUR INSIGHTS
Analyses & Perspectives
March 11, 2026
Generative AI in the enterprise: what the 2026 threat landscape changes for technical teams
Generative AI is not only changing the threat landscape. It is also changing how teams need to think about architecture, connectors, permissions and usage governance. What technical teams actually need to frame in 2026.
Read article →February 24, 2026
Data breaches: why MFA is now the sine qua non of trust.
Breaches keep coming, credentials keep circulating. In 2026, the right question is no longer how to protect your password: it is how to design authentication so that a stolen password has no operational consequence.
Read article →February 18, 2026
Open source and self-hosted AI models: real capabilities, real constraints
Llama, Mistral, Qwen, Gemma: open source models have considerably reduced the gap with frontier models. But 'free' does not mean no cost, and 'open source' does not mean no constraints. What you really need to know before choosing.
Read article →Regain control of your system, and keep it
A first conversation lets us quickly assess your context, risk areas and the most relevant trajectory, without aggressive sales pitch.