Software Engineer III - Linux & AWS

<div class="content-intro"><p> </p> <div> <h2><strong>Company Overview</strong></h2> </div> <div> <p>Arcesium is a global financial technology firm that solves complex data-driven challenges faced by some of the world’s most sophisticated financial institutions. We constantly innovate our platform and capabilities to meet tomorrow’s challenges, anticipate the risks our clients encounter, and design advanced solutions to help our clients achieve transformational business outcomes. </p> </div> <p>Financial technology is a high-growth industry as change and innovation continue to disrupt the status-quo and prompt major transformation. Arcesium is at a particularly interesting time in our own growth as we look to leverage our successfully established market position and expand operations in pursuit of strategic new business opportunities. We value intellectual curiosity, proactive ownership, and collaboration with colleagues, and we empower you to meaningfully contribute from day one and accelerate your professional development.</p></div><p>We are looking for someone who will own the architecture and health of the Linux side of Developer Compute — the fleet of AWS WorkSpaces, WSL, and Linux config that thousands of engineers build on every day. You'll set the standard for how the team ships Ansible changes through peer review, do the deep OS-internals work that keeps the fleet healthy, and act as the final technical authority when a problem survives first-line and self-service troubleshooting. This is a hands-on senior Unix engineering role: you diagnose from strace and journalctl, design the fix at the platform level, and make sure it's codified so the same problem doesn't recur across the fleet.</p> <p><strong> The Role at a Glance</strong></p> <ul> <li>Architect and own the Linux compute platform — the design decisions behind AWS WorkSpaces, WSL, and the broader Linux fleet that thousands of engineers build on daily.</li> <li>Set the automation standard: define how configuration, patching, and lifecycle management are codified in Ansible and enforced through engineering review, not just author individual changes.</li> <li>Act as the final technical authority on hard Unix/identity/infrastructure problems — the ones that survive first-line and self-service troubleshooting.</li> <li>Drive the platform's technical roadmap: OS/region expansion, deprecation of legacy images, and R&D into Unix-ecosystem capabilities the fleet doesn't yet have.</li> </ul> <p><strong>What You'll Do:</strong></p> <ul> <li>Resolve fleet-wide health issues at the root: Investigate unhealthy/stuck/disconnecting WorkSpaces reported daily by end users — stale desktop-session state, broken shell config after a distro migration, disk/memory exhaustion, CloudWatch-reported anomalies — and fix the underlying cause via Ansible rather than a one-off reboot.</li> <li>Own Ansible for the Linux/WorkSpaces fleet: Author and review playbooks and roles covering package management, DNS/nameserver config, credential-refresh scripts, PAM/Kerberos, and systemd-based job scheduling; land changes through a peer-reviewed merge-request workflow with staged rollout and a rollback plan.</li> <li>Troubleshoot auth and identity plumbing: Debug Kerberos/KCM cache issues, kinit failures, GSSAPI/publickey SSH auth errors, and STS regional-endpoint assumptions across accounts — the kind of problems that show up as "VSCode SSH won't connect" but trace back to credential caches or IAM endpoint config.</li> <li>Keep package management and toolchains working: Own issues across modern and traditional Linux package managers and internal package repositories — SSL/cert trust issues, GPG signature failures, re