System Engineer

We are looking for an experienced Systems Engineer with deep Windows Server expertise to join our infrastructure team. This is a hands-on technical role with real variety - spanning day-to-day operations, incident resolution, and proactive improvements across a complex, multi-tenant AWS environment.

You’ll take ownership of Windows infrastructure work at all levels of complexity, working closely with senior engineers on challenging problems and contributing directly to the reliability and growth of the platform.

Key Responsibilities

Windows Server & Active Directory

• Administer and maintain Windows Server environments (2016/2019/2022) across multiple customer tenants.

• Design, deploy, and troubleshoot Group Policy Objects (GPOs) to effectively secure customer-facing environments, including AppLocker policies to restrict access to shell executables.

• Manage NTFS and share permissions across multi-tenant file server environments.

• Administer and support our RDS/TSplus environment during migration to new platforms.

AWS Infrastructure

• Operate and support a fleet of over 600 Windows and Linux EC2 instances using monitoring and patching tooling.

• Support customers during migration to and day-to-day use of WorkSpaces Applications (AppStream 2.0).

• Troubleshoot and manage AWS networking infrastructure including VPC routing, Security Groups, and related services.

• Work across multi-region, multi-account AWS environments with a clear understanding of tenancy boundaries.

Identity & Access

• Administer Okta: users, application assignments, and MFA configuration.

• Troubleshoot federated identity issues across Active Directory and Okta.

Security & Compliance

• Maintain security hardening standards across Windows Server and Linux environments.

• Respond to and document security incidents, including root cause analysis and follow-up remediation.

Monitoring & Troubleshooting

• Use Zabbix and bespoke internal tooling to monitor infrastructure health and respond to alerts.

• Diagnose and resolve complex issues across networking, DNS, authentication, and application layers.

• Produce clear incident documentation, root cause analyses, and post-incident reports.

• 5+ years of hands-on Windows Server administration in a production environment.

• Strong Group Policy experience: creating, troubleshooting, and documenting GPOs in complex Active Directory environments.

• Solid Active Directory fundamentals: OU structure, group management, delegation, and policy inheritance.

• Experience with RDS or TSplus environments, including multi-session management and profile handling.

• NTFS and share permission management, including inheritance, auditing, and remediation.

• Comfortable working in AWS at an operational level: EC2, VPC, IAM, S3, Route 53.

• Networking fundamentals: VPN configuration, DNS, routing, and firewall rules.

• Strong, methodical troubleshooting approach - able to isolate issues systematically and document findings clearly.

• Experience working in a Managed Service Provider or multi-tenant environment.

Desirable Skills

• AWS certification, or actively working towards it.

• Familiarity with WorkSpaces Applications (AppStream 2.0).

• Okta administration experience.

• Exposure to SAP Business One environments.

• Linux fundamentals (SLES, Ubuntu) - sufficient to navigate and perform standard administration tasks.

• Familiarity with Zabbix or CloudWatch monitoring.

• PowerShell scripting - able to write and maintain scripts for administration and automation tasks.

Personal Attributes

• Takes ownership and follows through - doesn’t wait to be told twice.

• Comfortable with ambiguity; able to investigate and resolve issues without a full brief.

• Clear and direct communicator - written and verbal.

• Methodical under pressure; documents as they go.

• Proactively surfaces risks and blockers rather than hoping they resolve themselves.

• Works well independently in a remote-first team.

Pulled from the full job description

• Free parking
• Company pension
• Casual dress
• Work from home

• On-site parking, * £30-36,000, dependent on experience.

• Remote-first working with flexibility.

• Exposure to a broad and genuinely complex technical environment.

Pay: £30,000.00-£36,000.00 per year

Benefits:

• Casual dress
• Company pension
• Free parking
• On-site parking
• Work from home

Ascarii are an SAP Gold Partner and AWS Partner with over 14 years of experience delivering SAP Business One cloud hosting and consultancy to clients and partners worldwide. As we continue to grow our global customer base and expand our SAP on AWS offering, we’re looking for a Systems Engineer to join the team and help us maintain the high standard of support our customers expect.

Our Operations Technical Team is based in Sedgefield, UK, with additional team members working remotely. We believe in getting the balance right - we expect everyone to own their work and take pride in what they deliver, but you’ll never be left to struggle alone. The team is genuinely collaborative, and whether you’re dealing with a complex incident or working through something unfamiliar, there’s always someone to think it through with.