C# .net Software Engineer

C# .net Software Engineer (senior) – Application Support & Systems Integration FRENCH/ENG

Location: Brussels / Zaventem Start: ASAP. FREELANCE

We are looking for a hands-on Software Engineer to join a technical team responsible for maintaining, supporting and integrating business-critical software applications.

The role combines software development, application support, troubleshooting, systems integration and configuration. You will take ownership of production issues, perform root-cause analysis, implement fixes and work across application, database, infrastructure and networking layers.

Key Responsibilities

• Provide 2nd/3rd line application support and resolve complex production issues.
• Diagnose problems across software, databases, networks and system interfaces.
• Perform root-cause analysis and implement permanent fixes.
• Develop and maintain system integrations and data interfaces.
• Work with APIs, messaging systems and real-time data flows.
• Configure and maintain high-availability and redundant environments.
• Support software deployments, testing and system configuration.
• Collaborate with developers, infrastructure teams, technical teams and external stakeholders.
• Produce technical documentation, troubleshooting guides and operational procedures.
• Contribute to software stabilisation, refactoring, automation and CI/CD initiatives.
• Help modernise test environments and improve overall system reliability.

Technical Skills

Programming

• C# / .NET Framework / .NET Core
• Python (an advantage)
• PowerShell / Bash
• Multi-threaded and event-driven applications

Databases

• SQL Server / PostgreSQL
• Complex SQL queries and stored procedures
• Performance tuning
• Database redundancy/failover
• Data migration and ETL

Integration & Messaging

• OPC UA / industrial communication
• MQTT / AMQP
• TCP/IP and socket-level troubleshooting
• XML / JSON
• Message brokers
• Real-time data processing and event-driven architectures

Infrastructure

• Windows Server
• Linux / Red Hat / CentOS
• VMware / Hyper-V
• VPN, RDP, SSH
• Remote access and secure connectivity

DevOps & Tools

• Git / GitLab / GitHub
• CI/CD pipelines
• Docker
• Jira / Confluence
• ITIL / service management

Networking & Security

• TCP/IP
• Firewalls, proxies and NAT
• TLS/SSL and certificate management
• Secure remote access
• Network segmentation and DMZs

Experience Required

• 3+ years' experience in Software Engineering, Systems Integration, Application Support or a similar technical role.
• Strong debugging and root-cause analysis capability.
• Comfortable troubleshooting complex systems across multiple technical layers.
• Experience working in production/mission-critical environments is advantageous.
• Strong communication and technical documentation skills.
• Able to work independently while collaborating with technical and business stakeholders.

Nice to Have

• Industrial automation / SCADA / PLC experience
• Experience with DevOps and CI/CD
• Infrastructure-as-code exposure
• ITIL/service management experience
• French language skills
• Experience in logistics, transportation or other 24/7 operational environments

The mindset is crucial.

The ability to influence, change, want to change/improve and get stuck in

top firm, top management, lots of work. Not always easy and always a challenge

If you get to this bit, you must be keen and thorough (good work), email me direct, nic.simic@mbaswitzerland.com