Senior Systems Administrator; Windows Infrastructure

Position: Senior Systems Administrator (Windows Infrastructure)
We are looking for a Senior System Administrator to complete our consultants Workforce Management Serviceon behalf of the European Space Agency (ESA) for their location in Noordwijk,The Netherlands. Please beinformedthis position requires full on-site support.
Please note, the successful candidate will be employed by ATG Europe (or one of its subsidiaries). Furthermore, upon selection, they will be subject to a general security screening performed by an external provider (further information will be provided at the interview stage).
ATG is dedicated to diversity and inclusion and is an equal opportunity employer. Regardless of race, color, religion, sex, sexual orientation, gender identity, national origin, age, handicap any other reason protected by relevant state or municipal legislation, we are pleased to consider all eligible candidates for employment.
The successful candidate will be tasked with, but not limited to:
Administer and maintain the on-premises Microsoft Configuration Manager (Config Mgr/SCCM) infrastructure, including site servers, SQL databases, distribution and management points, boundaries, collections, and client health;

Monitor system availability and performance; analyse logs, alerts, and user-reported incidents; and implement timely corrective and preventive actions;

Support ESA/ESTEC Technology Labs users with Windows system deployments, upgrades, maintenance, and hardware changes, including memory, storage, and network interface components;

Manage server patching and update deployment, including software update groups, maintenance windows, compliance reporting, remediation, and controlled rollback where required;

Perform operating system deployment, application packaging, and task‑sequence management for server builds; maintain standardised automation and troubleshoot deployment failures;

Maintain accurate technical documentation, configuration records, operating procedures, and evidence required for service reviews, audits, and knowledge transfer;

Collaborate with team members on major incident resolution, root‑cause analysis, problem management, and the delivery and closure of infrastructure projects;

Coordinate with corporate IT services, networking, cybersecurity, and facility management teams, as well as external suppliers where applicable;

Work in accordance with ITSM practices and IT Service Operations processes and tools, with onsite presence Monday to Friday from 08:30 to 17:30.

Master’s degree in computer science, information technology, systems engineering, or a related discipline, with at least four years of relevant professional experience; or

Relevant IT studies or equivalent technical qualifications, with at least ten years of progressively responsible experience in enterprise Windows infrastructure administration;

Strong professional communication, stakeholder-management, and teamwork skills, with the ability to explain technical matters clearly and produce concise operational documentation;

Advanced hands‑on knowledge of Microsoft Configuration Manager (Config Mgr/SCCM), including infrastructure administration, client management, software distribution, patching, application packaging, operating system deployment, task sequences, and compliance reporting;

Strong Windows Server administration skills, including hands‑on knowledge of Active Directory Domain Services (AD DS), domain controllers, users and groups, organisational units, Group Policy, trusts, replication, delegation, authentication, permissions, DNS integration, Active Directory SSO, Kerberos, Power Shell scripting, security hardening, and troubleshooting in enterprise environments;

Sound understanding of network and storage fundamentals, including firewalls, routers, switches, DMZs, WAN,…