Company Description

Are you passionate about energy, sustainability, and technology, with a drive to create impactful backend solutions?

Flexcity, a leading European energy tech company within the Veolia Group is looking for a resourceful Senior Frontend Developer to join our French team.
 

This position offers the opportunity to join the Flexcity R&D team in France, alongside a team of skilled colleagues from different backgrounds, within the company headquarters in Brussels.

 

At Flexcity, Tech is not a support function — it is a key business driver. We operate in a complex, real-time, and highly regulated environment, requiring robust, secure, and adaptable systems to manage the increasing volatility of energy markets.

 

Job Description

Role

As a Senior Frontend Developer you will play a pivotal role in crafting and elevating our user interfaces and web applications. You'll drive feature development while ensuring code excellence through thorough reviews and mentoring junior developers. Working closely with cross-functional teams, you'll contribute to our technical strategy and deliver robust, scalable frontend solutions that empower our platform to manage real-time energy flexibility across Europe.

 

You will be part of our tech team, under the UI Team Manager , and your role is divided in:

 

Feature development & delivery - 60% 

Implement complex UI features in React/TypeScript

Collaborate with product teams

Own user-facing experiences from idea to release

Evaluate technical feasibility

Align with backend teams

 

Quality, reviews & mentorship - 30% 

Conduct in-depth code reviews

Ensure architectural consistency

Uphold best practices in performance, accessibility, and typing

Pair programming and guiding mid/junior engineers

Onboarding new developers

Write or maintain internal documentation and ADRs

 

Tech strategy & cross functional collaboration - 10% 

Design scalable UI architecture

Enforce frontend patterns

Lead structural refactors

Improve build tools, linting, and CI pipelines

Contribute to roadmap decisions

Contribute to component documentation / mockups (Figma, Storybook)

Qualifications

Hard Skills

   Must Have 

 

Fluent in English and French 

Strong front-end development expertise

Testing proficiency

Architecture principles

Component libraries & design systems

Tooling & DX expertise

 

Nice to have

UX sensibility

DDD / Hexagonal Architecture

Observability

 

Soft Skills

Strong communication skills

Leadership Skills

Mentoring and knowledge sharing

Problem-solving mindset

Stakeholder management

Meticulous attention to detail

Product-oriented thinking

Additional Information

Why Join Flexcity?

 

Impact            Be part of our key Technology team, with a direct impact in the decarbonisation of our industry

Purpose            Contribute concretely to a greener future, both in France, and globally

Scale-up           Work in an agile environment, getting structured and more efficient, but still with a large                                    freedom and strategic decision making available at all levels of the company

Group                Benefit from a close relationship with the Veolia group, a global leader in the ecological and                               energy transformation

Innovation         Engage with cutting-edge energy technology and markets

Supported         Get backing from dedicated central support teams in  Product and Portfolio, in order to                             get you the best tools, training and sounding board to work in the best environment

Community       Engage with a team spread across multiple countries, learning and innovating together.                                     Connect with diverse teams across Europe through regular team-building events, both                                       within  Flexcity and Veolia

Training            Develop your hard and soft skills with dedicated training made available, as well as strong                                learning curve within your position 

Hybrid              Experience international collaboration and flexible work schedules, including 2 work-from-                                  home days

 

About Flexcity

Flexcity is a uniquely positioned energy technology company in the Internet of Energy sector. It is a leading demand response aggregator in Europe, rapidly growing and expanding to new regions. Flexcity’s core activity consists of supporting the power grid balance through the operation of its large portfolio of flexible fully-automated assets. 

 

The Flexcity portfolio consists of a wide range of technologies such as batteries, eBoilers, CHPs, generators, wind farms, solar parks and large industrial processes. 

 

As a provider of smart energy management services based on innovative smart grid technology, Flexcity applications focus on demand-side optimization and management (Demand Response, Load Shifting, etc.). Flexcity supports many industrial companies in reducing their overall electricity costs by providing demand-side management services based on innovative optimization and modelling software applications.

 

Flexcity is truly at the cutting edge of energy innovation. As a member of the team, you will contribute to a sustainable low-carbon energy sector.

 

 

As an inclusive company, Veolia is committed to diversity and gives equal consideration to all applications, without discrimination.