Software Engineer Fullstack Expérimenté

About the role

You will own the full lifecycle of digital product development as a Software Engineer Fullstack at Theodo, designing and building innovative solutions from initial concept through to production deployment. You will partner closely with product managers and tech leads to translate complex business requirements into high-performing, maintainable applications. Your daily work will involve investigating intricate technical issues, debugging defects, and applying creative problem-solving to ensure robust and scalable solutions. You will leverage modern tools, including working with LLMs, to accelerate development cycles without compromising on quality or best practices. You will be responsible for delivering code that meets strict deadlines while integrating continuous refactoring and adhering to team standards across diverse technology stacks. This role requires a deep understanding of both frontend and backend systems to craft cohesive and user-centric products. Ultimately, you will contribute directly to the success of prestigious client projects that impact major digital platforms.

Key facts

What you'll do

Investigate and resolve complex technical problems by analyzing deep codebases to identify root causes and develop sustainable solutions.

Produce high-quality code within demanding deadlines, integrating rigorous testing, systematic refactoring, and strict adherence to team technical standards regardless of the technology employed.

Collaborate closely with product managers and tech leads to fully understand client problems and evolve products in alignment with user needs throughout the entire production cycle.

Work within cross-functional project teams composed of software engineers, tech leads, and product managers to deliver innovative digital products for clients.

Utilize modern development tools, including experimentation with LLMs, to accelerate development processes while ensuring code quality and maintainability.

Perform debugging and corrective actions on defects in any environment, ensuring resolutions are permanent and do not introduce regressions.

Engage in continuous learning to master new technologies such as Java (Spring Boot), Angular, Node (Nest), React (Next), and Python as required by diverse projects.

Analyze and refactor legacy systems during migrations, such as moving monolithic e-commerce platforms toward composable architectures to achieve long-term scalability and security.

Participate actively in architectural discussions and design-to-cost approaches to modularize platforms and manage complex production constraints, including coordinated deployments across large-scale client environments.

Contribute to the strategic evolution of products like iDealwine® or Sevetys, navigating challenges such as data structuring, performance optimization, and seamless integration without service interruption.

Develop a comprehensive understanding of the end-to-end product lifecycle, ensuring that solutions are not only functional but also durable and aligned with client value propositions.

Act as an active member of a self-organized team, sharing knowledge, mentoring peers, and driving collective technical excellence.

Explore and pilot emerging technologies in specialized groups focused on areas like cybersecurity, serverless architecture, performance, and GreenIT initiatives.

Build a personalized career path towards advanced technical leadership roles such as tech lead, senior architect, or specialist evangelist under the guidance of Theodo's coaching framework.

Requirements

You possess more than eight years of professional experience as a software engineer with a strong track record in fullstack development.

You hold a proven ability to write clean, maintainable, and efficient code while adhering strictly to industry-standard quality practices.

You demonstrate mastery over core programming concepts and software design principles, enabling you to adapt rapidly to new languages and frameworks as project needs evolve.

You have a history of successfully delivering complex software projects from initial conception through deployment, managing both technical and functional requirements.

You are comfortable working in dynamic, multidisciplinary teams where clear communication and collaboration with non-technical stakeholders are essential.

You show resilience and resourcefulness when debugging difficult issues, applying analytical thinking to devise long-term solutions rather than quick fixes.

You have hands-on experience with at least one modern frontend framework such as Angular or React, and at least one backend technology such as Node, Java with Spring Boot, or Python.

You are committed to continuous learning and actively seek opportunities to deepen your expertise through training, community involvement, and peer knowledge sharing.

Nice to have

Prior experience working on large-scale enterprise applications and participating in legacy system migrations is highly valued.

Familiarity with DevOps practices, CI/CD pipelines, and cloud infrastructure will strengthen your ability to manage production deployments effectively.

Experience contributing to open-source projects or tech community groups is appreciated as it reflects engagement with the broader developer ecosystem.

Practical notes

This position is based in Paris and is offered as a permanent contract (CDI).

Candidates must be able to commit to long-term career development within Theodo, aligning with structured coaching and training programs.

Relocation support and visa sponsorship discussions are available for international candidates as required by French regulations.