Développeur Full‑Stack Senior .NET / React

About HCLTech

HCLTech is a global technology company with over 225,000 employees in 60 countries, offering digital, engineering, and cloud solutions. The company supports major sectors such as financial services, industry, healthcare, telecommunications, etc. Its 12-month revenue, closed in September 2024, amounted to 13 billion dollars. HCLTech France has over 500 employees, with offices in Paris, Lyon, Toulouse, and Blagnac.

Mission Presentation

The Senior Full-Stack .NET / React Developer contributes to the design, development, modernization, and optimization of enterprise applications covering front-end and back-end layers. The role includes delivering secure, high-quality software components using React, TypeScript, C#, .NET Core, SQL, and modern architectures. It also involves supporting production platforms, resolving complex technical incidents, and contributing to the scalability and maintainability of systems.

In an Agile environment, the developer collaborates closely with functional teams, architects, and operations to deliver reliable and high-performance solutions. The mission may extend to financial systems, real-time applications, data-engineering modules, or access management, depending on the context.

Responsibilities

• Design, develop, and maintain full-stack web components using React, TypeScript, C#, .NET / .NET Core.
• Ensure technical and functional evolutions, perform code reviews, and provide recommendations to improve quality and performance.
• Develop backend APIs, multithreaded services, data processing components, and calculation engines according to the mission scope.
• Optimize SQL queries, stored procedures, and database interactions (SQL Server, PostgreSQL, Oracle).
• Investigate and resolve complex anomalies, production incidents, and high-priority technical issues.
• Participate in deployments, production releases, and technical documentation and change management activities.
• Ensure a high level of code quality through unit, integration, acceptance, and automated tests, in line with clean code and software craftsmanship practices.
• Participate in Agile ceremonies and collaborate with multidisciplinary stakeholders in regulated, large-scale, or real-time environments.

Mandatory Skills

Backend (C# / .NET)

• Proven expertise in C#, .NET, .NET Core, API development, and backend services.
• Experience with multithreaded, high-performance, or real-time architectures (depending on context).
• Proficiency in Visual Studio, Windows environments, and PowerShell scripting.

Frontend (React)

• Strong experience with React.js, JavaScript/TypeScript, componentization, and front-end architecture.
• Good understanding of UI component performance optimization.

Data & Database

• Excellent SQL skills with SQL Server, PostgreSQL, or Oracle, including stored procedures.
• Understanding of data-engineering principles (for missions related to calculation engines).

Testing & Code Quality

• Experience in unit, integration, and acceptance testing, and in TDD/BDD approaches.
• Mastery of design patterns, refactoring, maintainability, and clean code practices.

DevOps & CI/CD

• Experience with Git, GitHub, and Git-based workflows.
• Knowledge of CI/CD pipelines (Jenkins, TeamCity, GitHub Actions, or equivalents).

Architecture & Functional Domains

• Experience in enterprise architecture design.
• Understanding of IAM (Identity & Access Management) concepts.

Communication

• Ability to work in English-speaking environments and communicate effectively.

Additional Skills (Assets)

• Knowledge of financial, trading, ALM/Liquidity, or large-scale regulated environments.
• Experience with DevOps tools, containerization (Docker), and orchestration (Kubernetes).
• Strong documentation skills, contribution to architectures, and knowledge sharing.

Specific Requirements

• Hybrid model: 50% on-site presence in the Paris / Île‑de‑France region.
• Experience in resolving complex technical incidents in real-time or critical environments.
• Ability to produce and maintain technical specifications, documentation, deployment guides, and change management elements.
• Proven experience in Agile/Scrum teams.
• Ability to work autonomously as a senior/expert and support users or stakeholders as needed.

Why Join Us?

At HCLTech, you will evolve within an international ecosystem where technical expertise meets daily innovation. We offer you a structured, stimulating, and human environment, where your progression is not just a concept, but a real career plan.

You will benefit from:

• Global career opportunities, thanks to a worldwide presence and a wide variety of projects.
• Real flexibility, essential for maintaining a sustainable work-life balance.
• High-value missions, allowing you to expand your skills and shape your role.
• Constant support, with training, mentoring, and skill development programs.
• An inclusive and collaborative culture that values commitment, passion for the job, and the desire to innovate together.
• Strong internal initiatives focused on well-being, diversity, and positive social impact.

Joining HCLTech means integrating a company where we build, we innovate, and we move forward — together.

For more information on how we process your personal data, please refer to HCLTech’s Candidate Data Privacy Notice.