Senior IT System Engineer (Freelance)Location: Brussels, Belgium (with travel to customer sites across Belgium)Start Date: ASAPDuration: Long-term assignment (2+ years)Contract Type: FreelanceAbout the RoleWe are looking for a Senior IT System Engineer to join a multidisciplinary team supporting critical railway infrastructure environments. You will play a key role in ensuring the availability, performance, continuity, and security of business-critical systems across on-premises, hybrid, and cloud environments.Key ResponsibilitiesManage, maintain, and optimize Linux-based infrastructure and VMware environments.Provide 2nd-line support, troubleshoot incidents, and ensure operational continuity.Participate in infrastructure migrations, system upgrades, patch management, and security improvements.Monitor and maintain high-availability production environments.Support infrastructure and application deployments during go-live and hypercare periods.Contribute to automation, documentation, testing, and continuous improvement initiatives.Collaborate with internal teams and customer stakeholders to deliver reliable IT services.Required Skills & ExperienceStrong experience with Linux administration (CentOS / RedHat).Hands-on experience with VMware technologies including vSphere, vCenter, and vMotion.Scripting experience using Bash and/or Python.Experience working within high-availability production environments.Good understanding of networking fundamentals, including VPNs, Firewalls, Routers, and Switches.Ability to work independently and within a team in a fast-paced environment.Fluent in Dutch and French.Nice to HaveVeeamPuppetNagiosElastic Stack / KibanaMySQL / PostgreSQLJira, Confluence, and GitWhat We're Looking ForStrong analytical and problem-solving skills.Excellent communication and documentation abilities.Customer-oriented mindset with a proactive approach.Flexibility regarding working hours and travel within Belgium.Ability to perform under pressure and support critical operational environments.Interested in learning more? Feel free to get in touch for additional details sihame@synctiv.be