Applications life cycle-Program Designer_developer-Expert Tech lead solution architect - C#.NET Do you want to be part of the energy transition towards sustainability and zero carbon through real-time energy management balancing? Are you passionate about software development and digital technologies? Tech lead and hands-on solution architect in C#.NET and Azure? With experience on software solutions with complex technical features? If so, come and join our team, help the energy transition by working on real-time software products that help balancing the electric grid (aFRR) and connecting the physical reality (batteries, renewable parks,…) in real-time to forecasters and optimizers to improve optimization results. About US (SEM) A global leader in low-carbon energy and services, relies on its Global Business Unit Supply Energy Management (GBU SEM) to provide reliable, sustainable, and affordable energy to all its customers. This strategic unit optimizes the Group’s and clients’ production consumption assets and designs tailored energy solutions for our 200,000 professional clients and 15 million consumers. The Global Business Unit Supply Energy Management leverages Client assets to deliver secure and sustainable energy to its B2B and B2C customers. It uses its expertise in energy management to provide decarbonized electricity 24/7. Joining Supply Energy Management means becoming part of a team of over 10,000 passionate experts spread across 20 countries, all united by a shared mission: shaping a greener and more efficient energy future. Together, we push the boundaries of innovation to deliver decarbonized energy 24/7. Join us and be part of those shaping the energy of tomorrow. Context As part of Customer commitment to decarbonization, SEM (Supply Energy Management) plays a key role in managing and optimizing the flexibility of generation assets (e.G., renewable, thermal), storage assets (e.G., battery) and consumption assets (e.G., devices which we can stop or slow down). In this context, we are 2 teams of information system architects and software developers working together with business colleagues to analyse, design, develop, maintain and support several products. Kiwi enables to exploit the flexibility of many small assets and to offer demandside management services. It is connected to these assets with an edge device or through an API. Real-time asset services ensure notably the real-time aFRR steering and the realtime data collection from the assets. The primary focus of the present mission is real-time asset services. aFRR dispatcher receives every 2 to 4 seconds the aFRR amount requested by the TSO (= grid operator), calculates in real-time the optimal allocation towards the aFRR bids and power assets (batteries, renewable parks, power plants in general) and sends every 2 to 4 seconds the individual setpoints to the concerned connectivity solutions. TimeFlux connects the physical reality of power assets to forecasters and optimizers. Concretely, it collects and processes the real-time data from power assets, with a low-latency streaming architecture, and exposes it to other software systems in the organization (e.G., forecasters, optimizers). GENCO connects the software systems with the industrial SCADA systems. Main activities As hands-on tech lead and solution architect, you will: Guide technically the development (3-5 people). Guide the discussion with functional analysts and with domain experts. Design architectural proposals, documented in diagrams, including APIs, services, front-end and back-end interactions. Sometimes autonomously, sometimes in team collaboration. Improve the delivery in general. You will supervise the team to ensure these activities as a team, and you will directly contribute to these activities (hands-on): Subdivide the proposal into agile progressive development upgrades. Implement builds and associated testing and maintenance tools. Develop back-end services and APIs. Write tests in collaboration with business colleagues. Document and develop user manuals. Provide user assistance and support. Monitor systems and provide level 2 support, incident resolution, and troubleshooting (root causes of recurring incidents). Hard Skills Required: at least 6+ years of software engineering technical design and architecture responsibilities. Education: a master as polytechnic engineer is a strong plus. The following abilities are required: Proficiency in C# Proven experience in designing and operating event-driven architectures (Kafka, Azure Event Hub, MQTT and/or Azure Service Bus) Solid understanding of distributed systems concepts: scalability, fault tolerance, backpressure, ordering, idempotency Hands-on experience with Azure cloud (if experience with AWS cloud, willingness to learn switch to Azure) Hands-on experience with Kubernetes in production environments, including autoscaling and deployments Experience with stateful systems such as Redis (caching use cases) Strong testing culture: unit tests, integration tests, and production validation Production-grade observability: metrics, logging, alerting (Grafana, Prometheus, or equivalent) Familiarity with agile development practices PostgreSQL, Redis, Azure Data Explorer (under testing) CI/CD: GitHub Actions, Continuous Deployment Experience with one of these technologies is a plus: o Scala (for KiWi cloud) o Rust (for KiWi edge) o Python (to collaborate with other teams and to refactor some Python code to C#). Soft Skills The following abilities are also required: Proactive mindset with a collaborative spirit and a willingness to support team delivery. Ability to break down complex problems and propose pragmatic, scalable solutions. Empathy, humility, and a strong sense of ownership and accountability. Leadership, good communication and interpersonal skills. Skills to match # Skill / Requirement Weight Expected Level / Criteria 1 Assignment stability in last 10 years (no short missions ≤ 24 months) 10 Yes 2 C#.NET – Senior Developer Solution Architect 10 Expert (+10 years) 3 Fluent in English (written oral) 10 Senior (8 4 Experience with complex process-driven applications (NOT simple websites, CRUD, workflows, DB-oriented apps) 10 Advanced (5 5 Leadership + Tech Lead experience 10 Confirmed (3 6 Master’s degree in polytechnic engineering (or equivalent in Computer Science) 10 Yes 7 Recent experience (3+ years) in Belgium, close to Brussels 10 Yes 8 Azure Cloud 7 Advanced (5 9 Fluent in French AND/OR Dutch 7 Advanced (5 10 Event-driven architectures (Kafka, Azure Event Hub, MQTT, Azure Service Bus) + distributed systems concepts 3 Advanced (5 11 Good written oral communication skills (clarity, assertiveness) 3 Expert (+10 years) 12 Kubernetes (Azure AKS) in production incl. autoscaling deployments 3 Confirmed (3 13 Organized rigorous 3 Expert (+10 years) 14 Strong testing culture (unit, integration, production validation) 3 Expert (+10 years) 15 Python (bonus) 1 Junior (Languages: Fluent in English. o Fluent in French or Dutch. Practicalities o Last reaction date: March 18th 2026 Preferred Start Date: April 1st 2026 Preferred End Date: 1 year contract, extendable with 2 additional Location, Brussel Belgium o Full tume (40h) o