Senior Harness Engineer (AI)

Location: Work from home, United Kingdom

Company

hirify.global is a global analytics software company providing decision-making solutions for businesses in more than 100 countries.

What you will do

• Design, build, deploy, and support harness components including agent guides, feedback loops, guardrails, shared context, and verification systems.
• Develop reusable agent instructions, architectural rules, reference documentation, codemods, custom linters, static analysis, and architecture-fitness tests.
• Define quality gates, release criteria, authority boundaries, and escalation rules for agent-produced work.
• Build LLM testing and evaluation infrastructure, including AI reviewers and consumer or contract testing such as Pact.
• Improve agent-work observability and measure cost per merged pull request, merge time, review velocity, defect escape rate, and agent-pull-request survival rate.
• Partner with product and platform teams, translate specifications into enforceable controls, and mentor engineers in harness practices and responsible AI-tool usage.

Requirements

• Bachelor’s or Master’s degree in Computer Science or a related discipline, or equivalent experience in software architecture, design, development, and testing.
• Strong software engineering experience with large, complex codebases, architecture, design, testing, and maintainability.
• Hands-on experience with AI coding agents such as Claude Code or Codex, including understanding where they succeed and fail.
• Experience building engineering tooling across linters, static analysis, CI/CD pipelines, containerized build and test environments, instrumentation, and observability.
• Experience with spec-driven development, context engineering, agent orchestration, fitness functions, developer platforms, and quality-gating processes.
• Knowledge of autonomous-agent security, including prompt injection, tool and permission scoping, sandboxed execution, audit trails, and least-privilege guardrails; excellent communication skills are required.

Culture & Benefits

• Inclusive culture guided by ownership, customer focus, and mutual respect.
• Professional development through learning experiences and opportunities to use individual strengths.
• Competitive compensation, benefits, and rewards programs.
• People-first environment with work-life balance, employee resource groups, and social events.