As a Network & Security Architect / Lead Engineer, you will join the Network & Security Team and play a key role in the design, evolution and implementation of the network and security landscape within a complex enterprise environment.The assignment combines approximately 50% architecture and design with 50% hands-on engineering and troubleshooting.Your main responsibilities will include:Defining and developing Network & Security architectures, including HLD and LLDEstablishing technical roadmaps and standardsLeading and supporting datacenter projects and migrationsTranslating business and technical requirements into scalable solutionsReviewing implementations and ensuring technical qualityContributing directly to operational support and complex L3 troubleshootingSupporting critical incidents and problem analysisCoaching and guiding engineers within the teamCollaborating with internal stakeholders and external partnersThis role requires a senior professional who can combine architectural thinking, technical leadership and hands-on expertise in a complex Network & Security environment. We are looking for a Senior Network & Security professional, typically with 8+ years of experience, combining proven architecture and design expertise with a strong hands-on engineering background.You have practical experience in complex enterprise and datacenter environments and are comfortable acting both as a technical architect and as a senior engineer involved in implementation and L3 troubleshooting.Required expertiseStrong experience in Network & Security architecture and designPractical Cisco ACI experience - mandatoryCisco NexusPalo Alto NGFW and PrismaFirewalling, VPN, segmentation and Zero TrustVMware NSXLoad balancingHigh-availability and mission-critical environmentsMulti-vendor enterprise environmentsExperience with complex migration and transformation projectsCisco certification (CCNP or higher) or equivalent expertise through experienceExperience with network automation, CI/CD and/or scripting is considered an advantage. PCNSE and/or Cisco ACI certifications are strong assets.You combine an architectural mindset with a hands-on approach, have strong analytical and problem-solving skills, and communicate effectively with both technical teams and stakeholders. You are comfortable coaching engineers, sharing knowledge and acting as a technical reference within the team.Fluent Dutch and English are required. Job BenefitsLong-term assignment: 12 months+, renewableHybrid working: approximately 4 days remote and 1 day per week onsite in BrusselsFull-time assignmentWork within a complex, enterprise-scale public-sector environmentCombination of architecture/design and hands-on engineeringExposure to business-critical Network & Security infrastructureOpportunity to act as a technical reference and coach within the teamFreelance / Time & Material contract