Senior IT Systems Engineer

The Senior IT Systems Engineer is the technical authority for internal IT systems - the senior individual contributor who sets the architecture, standards, and patterns that systems engineers build to, owns the hardest builds and migrations, and makes the design and build-vs-buy calls within the internal IT estate. Core ownership is the target-state design and the standard - the reference architectures, the golden-image / infrastructure-as-code patterns, the automation framework, and the hardening / patch / backup baselines - delivered across the identity, endpoint, virtualization, cloud-IaaS, and automation stack. This is a senior individual-contributor seat reporting to an IT Manager or Head of IT, with technical-decision ownership of how the internal systems are built across the estate, deep partnership with the security team, and a mentoring relationship to the systems engineers. It is not an IT Manager (this seat sets technical direction and mentors, but owns no people, no budget, and no vendor contracts - it recommends and escalates those up), not the base IT Systems Engineer who executes builds and runs the joiner-mover-leaver, patch, and backup work to the standard (this seat defines that standard and the architecture and leads the major projects), not the Security Engineer who owns the security program and its detections (this seat defines and implements the hardening baseline and partners), and not a senior generalist, senior cloud, or SRE engineer running the customer-facing production platform (the focus here is internal-systems depth - infrastructure, identity, virtualization, reliability - on corporate IT). Performance is visible in the reliability and coherence of the estate the standards produce, the success of the hard migrations led, and the level the engineers mentored operate at - so better architecture produces measurable, compounding business impact. What separates great from average at this altitude is setting standards that multiply across the estate rather than building one more excellent snowflake: a reference architecture and a paved-road build pattern every engineer follows so the estate is coherent and reproducible, a hardening and recovery baseline defined with security and enforced as state, a build-vs-buy call made on total cost and lock-in rather than a demo, a migration led so the business barely feels it, and engineers who leave a mentoring relationship building to a higher bar. A mediocre senior hoards the hard systems and becomes the single point of failure at a higher pay grade; a great one turns the hardest problem into a pattern the whole team can run.