Interim Staff Systems Engineer - IT & Infrastructure (d/f/m)

Our story: Every year millions of people are either filing their taxes in fear or giving up on their tax refund altogether. We're working on fixing that. Our intuitive app enables anyone, regardless of education or background, to file their taxes with newfound confidence. Spread across Germany, Spain and the UK, the team at Taxfix Group with its brands Taxfix and Steuerbot, is a compassionate group of solution-finders. We speak our minds openly, and with over 400 professionals, including tax experts, developers, and IT security experts, we're rich in ideas and voices. The group has facilitated more than 3.5 billion euros in tax refunds for its customers since its founding in 2016. The opportunity (Interim/Freelance basis): As our Staff Systems Engineer within the IT & Infrastructure team, you'll be responsible for keeping the enterprise systems that power Taxfix running reliably, securely, and intelligently — from cloud infrastructure and identity management to network, device, and application performance. Reporting to our Director of IT & Infrastructure, and collaborating closely with cross-functional stakeholders across the business, you'll architect and operate the backbone that enables every team at Taxfix to do their best work. In a company that moves fast and thinks big, you'll be the person who makes sure the foundation never wobbles. This is an interim position on a freelance basis. Your responsibilities: Maintain and operate enterprise cloud infrastructure that serves employees and internal systems, ensuring high availability, performance, and security at all times. Lead and evolve identity management across the enterprise — including platform management and Okta — developing concepts and processes to govern both human and agentic identities in a scalable, secure way. Support the integration of new tools and systems based on business requirements, owning the technical evaluation, onboarding, and configuration end to end. Ensure enterprise systems remain up to date, with security configurations, patches, and compliance standards consistently applied across the board. Maintain security backups and redundancies for enterprise infrastructure, proactively identifying and closing gaps before they become incidents. Manage and improve network, device management, and systems, keeping the environment stable, modern, and fit for a growing, hybrid workforce. Develop automations, AI-powered and agentic solutions, and scripts that reduce manual toil and improve the efficiency of infrastructure maintenance. Provide third-level support for cloud applications, acting as the deepest technical escalation point for complex issues and enablement of internal app deployment. Collaborate with SRE and platform engineering to assess risk, develop guardrails, and resolve incidents together with application owners. Collaborate with the Director of IT to continuously improve the enterprise architecture and infrastructure landscape, contributing strategic thi