Senior Software Developer

Role Overview

As a Senior Software Developer with strong back‑end capabilities and a good understanding of front‑end development, you will be involved in transformation projects at our clients. You will execute project assignments in software development, modelling and digital transformation environments, with a good deal of business perspective.

• Back‑end development: designing, developing and maintaining robust, scalable and secure applications, APIs and system integrations using Python and Type Script/Node.js (Java as a nice to have), with mainstream frameworks such as Flask, Django, Spring Boot and Express; building data and service layers with tools such as SQL Alchemy, Marshmallow and Alembic; and working with API architectures and integration patterns across distributed systems, including REST and GraphQL.
• Front‑end contribution: supporting the implementation of user‑facing features and collaborating on interface development when needed, using modern front‑end technologies such as Type Script, React, Angular and Vue.js, along with tooling and frameworks such as Vite, Next.js and Nuxt.js.
• Dev Ops and software delivery: contributing to CI/CD pipelines, containerised deployments and release processes in Git Lab CI/CD, Docker and Kubernetes environments, with attention to code quality, testing, observability and maintainability.
• Big Data and cloud: applying algorithmic knowledge to large‑scale data processing using technologies such as Apache Spark, Kafka, Airflow, Flink and Hadoop, and contributing to the design, deployment and operation of cloud‑native data platforms across Azure, AWS and GCP, including modern environments such as Databricks, with exposure to scalable storage, compute, orchestration and distributed processing architectures.

• Development and reinforcement of our offer, by contributing to the structuring of our software, data, cloud and AI offerings, building points of view on emerging technologies and helping define relevant solution approaches for our clients.
• Business development, by contributing to one‑on‑one definition and participating in our commercial initiatives, helping translate business needs into modern software, data and AI solution architectures.

• You have a Master’s degree.
• You have 3‑6 years relevant working experience.
• Analytical mind, exploring options and able to synthesize into conclusions.
• You’re a fast learner, communicative, flexible and entrepreneurial.
• You have a strong interest in data and AI‑related topics, the ability to quickly build expertise in these areas, and you’re excited about helping our clients seize the opportunities they offer.
• Excellent English, Dutch and French verbal and written skills are required. If you also speak German fluently, that’s a great plus!
• Passionate about Energy!

• An international company that gives importance to diversity, inclusion, employee well‑being and corporate social responsibility actions.
• A great working atmosphere with friendly and professional colleagues where innovation and entrepreneurship are encouraged.
• A personal development plan with regular follow‑up, as well as training opportunities to develop yourself.
• A competitive salary with great advantages, like a mobility budget or company car, hospital insurance, performance‑related bonus, etc.

We are unable to provide a work permit for this position.

Sia is an equal opportunity employer. All aspects of employment, including hiring, promotion, remuneration, or discipline, are based solely on performance, competence, conduct, or business needs.