Relout is a place created by ambitious people with a passion for technology. We work for international projects and clients from various industries, helping startups, software houses, and enterprises to transform and scale their businesses. We’re a boutique consulting (https://relout.team) & technology (https://relout.cloud) partner that builds the foundation to scale for our client’s success. Our mission is to connect best-in-class, passionate engineers with fast-growing digital & technology companies.We are currently looking for a Senior Systems Engineer to join a long-term project for one of our strategic clients in the UK.This is a senior, hands-on role with strong ownership over the Microsoft-based infrastructure in a complex, multi-site environment. You will be responsible not only for operations, but also for technical decisions, architecture, improvements and acting as the final L3 escalation point.You will work closely with the client’s Central IT Services team, local IT Managers, and external vendors on infrastructure operations, migrations, and automation initiatives, where fluent English communication is essential for daily collaboration.🔷Responsibilities:Take full ownership of the central IT infrastructure, ensuring stability, scalability and long-term maintainability across multiple locationsDesign, manage and continuously improve the Microsoft 365 environment (Entra ID, Intune, Exchange Online, SharePoint, integrations, security)Own and develop Windows Server environments (2016–2025) and Windows 10/11 endpoints using Active Directory, Azure AD and Group PoliciesAct as the highest technical escalation point (L3) for complex infrastructure incidents and requestsMaintain and develop on-prem infrastructure based on VMware ESXi clusters, including upgrades, migrations and performance optimisationLead infrastructure improvements, automation initiatives and standardisation to reduce manual overhead and increase reliabilityCollaborate directly with IT Managers and external vendors on project planning, technical scoping and deliveryCreate and maintain high-quality technical documentation, build standards and operational proceduresProactively identify architectural risks, bottlenecks and opportunities for optimisation across the environment🎯Requirements:6–8+ years of commercial experience in roles such as Senior Systems Engineer, Senior SysAdmin, Senior Platform Engineer, or similarProven experience working with ownership of production environments, not only operational supportAdvanced hands-on experience with Microsoft 365 (Entra ID, Intune, Exchange, SharePoint, SSO, integrations)Strong experience with Microsoft Windows Server (2016–2025) and Active Directory / Group Policy at senior/L3 levelStrong hands-on experience with VMware (ESXi, clusters, upgrades, migrations)Experience working in hybrid environments (on-prem + cloud)Confidence acting as final escalation point and taking responsibility for complex technical decisionsSolid understanding of core networking (DNS, DHCP, NTP, SNMP)Experience with monitoring tools (e.g. NinjaRMM, PRTG/SPRTG, SNMP-based tools)Strong analytical mindset and ability to solve root causes, not only symptomsAbility to work independently and communicate effectively with technical and non-technical stakeholdersEnglish level: minimum C1 (daily work with UK-based client) ⭐What we offer:Flexible contract currency of your choice (PLN/EUR/GBP)Flexible work arrangements and remote work optionsProfessional development and training opportunitiesCollaborative and inclusive work environmentRegular company events and integrations (meetups)Unlimited legal advice & support with B2B partnership and self-employmentMissing anything you like? Luxmed, Multisport? Ask us about it!Apply now! Join the Relout Team today! 📢