2 days ago

Agent Harness Engineer - Core Runtime

NinjaTech AI

Sydney

2 days ago

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NinjaTech AI is seeking a Core Runtime engineer to own the agent harness that powers autonomous AI agents. The role involves designing the run loop, orchestrator, and monitoring layer, and requires 4+ years of Python backend experience and familiarity with LLM APIs.

Core AIRemoteFull-timeMid LevelPythonConcurrency

Agent Harness Engineer - Core Runtime

Apply

Core AIRemoteFull-timeMid LevelPython

Salary

Not specified

Work Location

Sydney, New South Wales, Australia, AU

Work Model

Remote

Experience Required

4 years

Employment Type

Full-time

Experience Level

Not Applicable

Core Qualifications

Technical (Must-have)

PythonConcurrencyProcess supervisionFault-tolerant designLLM APIsAgentic patternsTool callingFunction callingStreamingBackend systemsSystems software

Soft Skills

Engineering rigorScientific curiosityCollaboration

Preferred Qualifications

Technical (Nice-to-have)

SandboxingContainerizationSecure code execution

Key Responsibilities

•Design and evolve the agent run loop: context management, turn compaction, and recovery from failed or partial tool calls
•Build the orchestrator that launches, supervises, and hands off long-running background agents without losing state
•Implement the monitoring layer that detects stuck, looping, or runaway agents and intervenes safely
•Own the provider abstraction across model backends (Claude, Codex, and others) so the harness stays model-agnostic
•Make the harness observable end to end with structured telemetry, so failures are debuggable in production
•Keep the loop fast and cheap at scale while it powers millions of daily user interactions
•Research, design, and build the core run loop and orchestration that power autonomous agents
•Define how agents manage context, recover from errors, and hand off work cleanly
•Build rapid prototypes and proof of concepts to turn harness ideas into shipped product capabilities
•Stay up-to-date with agent architectures from research and industry, and fold the best ideas into our runtime
•Design self-healing mechanisms so agents degrade gracefully instead of failing hard
•Collaborate with cross-functional teams including applied science, product, and integrations

Agent HarnessCore RuntimePythonLLMAutonomous AgentsBackendSystems EngineeringRemoteFull-timeAI

Key Responsibilities

•Design and evolve the agent run loop: context management, turn compaction, and recovery from failed or partial tool calls

•Build the orchestrator that launches, supervises, and hands off long-running background agents without losing state

•Implement the monitoring layer that detects stuck, looping, or runaway agents and intervenes safely

•Own the provider abstraction across model backends (Claude, Codex, and others) so the harness stays model-agnostic

•Make the harness observable end to end with structured telemetry, so failures are debuggable in production

•Keep the loop fast and cheap at scale while it powers millions of daily user interactions

•Research, design, and build the core run loop and orchestration that power autonomous agents

•Define how agents manage context, recover from errors, and hand off work cleanly

•Build rapid prototypes and proof of concepts to turn harness ideas into shipped product capabilities

•Stay up-to-date with agent architectures from research and industry, and fold the best ideas into our runtime

•Design self-healing mechanisms so agents degrade gracefully instead of failing hard

•Collaborate with cross-functional teams including applied science, product, and integrations