Senior Full Stack Engineer - Agent Runtime & Platform

About the role

Sydney · Full-time · On-site/hybrid

Every agent task runs somewhere: a sandboxed container with a filesystem, a browser, tools and a time limit. This role owns that runtime and the platform services around it — the layer everything else in the product depends on.

WHAT YOU'LL DO

- Own the agent sandbox runtime: provisioning, isolation, scheduling, lifecycle and cost per task at scale.

- Build and own platform services — identity plumbing, secrets, metering, object storage, workflow orchestration, and the tool/connector abstraction layer.

- Drive the observability stack from instrumentation through ingestion to the dashboard people actually open during an incident.

- Harden infrastructure against the failure modes that surface to users as “the agent got stuck”, and keep the platform from becoming a bottleneck to growth.

WHAT WE'RE LOOKING FOR

- 5+ years building and operating production backend systems and platforms.

- Deep AWS (we are CDK-first) and container orchestration understanding below the level of configuration — schedulers, runtimes and isolation boundaries.

- Python strength, plus enough front end to build the internal tooling your platform needs rather than waiting for someone else.

- A bias for simplicity and pragmatism over architecture for its own sake.

See the posting on NinjaTech's site