Senior Linux Infrastructure Engineer

Company:  tastytrade  Role:  Senior Linux Infrastructure Engineer  Location:  Chicago, IL — Hybrid    About the Role  We are looking for a senior Linux engineer who is equal parts operator and builder. You will own the systems layer of our production environment — from the metal to the configuration management code. This is a hands-on role: you will jump into incidents, tackle challenging engineering problems, design systems that scale, and evaluate new software and architectures.  This is not a role where the abstractions hide the machine. You are expected to be curious about what is underneath and to be the person other engineers come to when a system is behaving in a way nobody can explain.  What You ll Do  Own Linux performance. Diagnose and tune systems under real production load: CPU scheduling and NUMA placement, memory and page cache behavior, disk and filesystem I/O, and network stack tuning.  Lead troubleshooting on hard problems. Work incidents methodically — form a hypothesis, find the cheapest test that falsifies it, and narrow the search rather than changing five things at once. Write postmortems, organize follow-up tasks, and future-proof the environment so the same issue does not recur.  Write and maintain configuration management code. Build infrastructure declaratively with Salt, Ansible, Chef, or Puppet, treating that code with the same standards as application code: reviewed, tested, and version-controlled.  Run containerized workloads. Build, deploy, and operate services on Kubernetes or Nomad, including scheduling behavior, resource limits, health checking, and the failure modes that only appear under contention.  Automate in Bash and Python. Replace manual runbooks with tooling and streamline repeatable work.  Operate core network services. Troubleshoot TCP/IP with confidence and bring solid networking fundamentals. Manage DNS and DHCP as production services — zone management, resolver behavior, TTL strategy, scopes, reservations, and relay configuration.  Operate the traffic and data tier. Configure and troubleshoot Nginx and HAProxy (routing, TLS termination, health checks, connection handling) and support Redis and RabbitMQ in production.  Manage virtualization. Provision and maintain guests across VMware, Xen, or KVM, including capacity planning, host maintenance, and live migration.  Handle secrets properly. Use Vault for secret storage, dynamic credentials, policy, and rotation — and help move the organization off whatever it was doing before.  Own observability. Maintain log aggregation on the Elastic Stack and alerting through Nagios, CheckMK, or Icinga. Tune alerts toward signal; an alert nobody can act on is a bug.  Work through change management and code review. Everything moves through Git and pull requests. You will review other people s changes as seriously as you expect yours to be reviewed.  Who You Are  6+ years in a Linux systems, infrastructure, or SRE role.  Expert-level Linux, specifically:  Performance analysis. You can go from a vague complaint to a named subsystem using the standard tooling — perf, strace, ss, iostat, bpftrace, or equivalents — and explain what the numbers mean.  Troubleshooting methodology. A disciplined, hypothesis-driven approach that works on a system you have never seen before. We care more about how you narrow the problem than about which commands you happen to know.  Systems fundamentals. Processes and signals, systemd, cgroups and namespaces, filesystems, and what actually happens when a host exhausts memory or file descriptors.  Declarative configuration management at production scale — Salt, Ansible, Chef, or Puppet. You have authored and maintained the code, not only run it.  Containerization and orchestration. Production experience with Kubernetes or Nomad, including the operational realities: scheduling, resource pressure, rollouts, and debugging a workload that will not start.  Scripting and automation. Strong Bash and working Python. You write code