Senior Site Reliability Engineer

Remote (US) — West Coast or Mountain Time Only.

Lumonus builds software that supports oncology care teams. With our Series B complete and US expansion underway, we're forming a new in-region engineering capability to support and onboard US customers. You'll work closely with our Australian engineering squads while acting as the technical anchor for reliability in the US.

We're looking for a Senior Site Reliability Engineer who loves troubleshooting, improving systems, supporting customers, and making production safer and more predictable. Someone who's a jack of many trades, master of a few, and genuinely enjoys diving into incidents, fixing root causes, and strengthening long-term reliability.

You'll thrive here if you're self-directed, collaborative, comfortable across time zones, and enjoy working directly with customers as much as with engineers.

What You'll Be Doing

• Contributing to the application and infrastructure stack for our applications around key areas like security, performance or observability
• Run customer onboarding: new infrastructure, networking (VPN/TGW) and validating it all works together with your deep understanding of how it fits together
• Improve observability across metrics, logs, and tracing
• Partner with Australian engineering teams to uplift reliability, instrumentation, and operations
• Debug across our web SaaS apps, AWS infrastructure, networking, and containers
• Lead and support production incidents; restore service fast and prevent repeat issues
• Work closely with Product & Clinical Success on technical issues for US customers
• Collaborate with Product & Clinical Success Leads to resolve technical issues and understand customer needs in the US Region

What You Bring

• 7-10 years engineering experience across SaaS and cloud applications
• Strong backend engineering skills (Python/Django ideal, data integration a plus)
• Deep AWS knowledge across networking, TGW/VPNs, IAM, and compute
• Experience with AWS ECS or Kubernetes
• Multiple years experience with Terraform
• Strong observability experience logs, metrics, tracing (DataDog)
• Experience leading incident response
• Strong communicator, comfortable working directly with customers
• Ability to operate autonomously and collaborate across regions
• Ideally you have been in a Software Product StartUp/Scale up

Why Join Lumonus

Lumonus builds software relied on by oncology care teams, so reliability matters. You'll be part of the small, senior team establishing our US engineering presence and shaping the culture of the new region alongside our Australian engineering groups.

You'll work closely with experienced engineers in Australia and partner across product and customer teams, solving meaningful technical problems and seeing the impact of your work quickly. The culture is low-ego, friendly, and supportive, people here take the work seriously, but not themselves. We help each other, communicate openly, and keep things light even when the problems are complex.

If you value solid engineering, collaborative teammates, and an environment where everyone is trusted to do their best work, you'll fit right in.