Senior AI Engineer — Agent Harness & Tooling

Preacta; City of Melbourne; Hybrid; AUD 270,000 - 330,000; Full time

Benefits offered by this job

Hybrid work arrangement

Top-compensation package up to AUD 300

Biannual offsites across Australia

Access to best-in-class AI tooling

Clear development and career growth

Job summary

Preact is seeking a Lead/Staff AI Engineer in Australia to own the tooling layer between engineers and AI coding agents. You will architect and hardened agent-authored code, while shaping technical direction and building an in-house AI capability from the ground up.

You will lead secure, scalable delivery with strong Ruby on Rails and PostgreSQL expertise, and a track record in developer tooling that others rely on. Hybrid work across Australia offered and a significant growth opportunity.

Qualifications

• 5+ years of software engineering experience with senior-level production systems.
• Strong Ruby on Rails and PostgreSQL experience.
• Hands-on experience with AI coding agents in a real codebase.

Responsibilities

• Architect and build the coding agent harness, including MCP servers, tooling, integrations and workflows.
• Prepare the core Ruby on Rails codebase for agent-authored changes with clear module boundaries and strong tests.
• Design evaluation frameworks to measure agent performance and workflow effectiveness at scale.
• Lead investigation of failures and performance issues and feed learnings back into the harness and agents.
• Own security, privacy and guardrail controls and automated checks that stop agent changes from regressing systems.
• Lead incident response for coding agent and supporting systems including triage and root cause analysis.
• Build reusable tooling and drive adoption of AI-native development practices across teams.

Skills

Ruby on Rails

PostgreSQL

AI coding agents

Developer tooling

MCP servers

AWS

Terraform

Incident response

Financial services domain

Tools

Terraform

AWS

Job description

Preact is seeking a Lead/Staff AI Engineer in Australia to own the tooling layer between engineers and AI coding agents. You will architect and hardened agent-authored code, while shaping technical direction and building an in-house AI capability from the ground up.

You will lead secure, scalable delivery with strong Ruby on Rails and PostgreSQL expertise, and a track record in developer tooling that others rely on. Hybrid work across Australia offered and a significant growth opportunity.