[Hiring] Senior AI Engineer - Harness Engineering @Cast AI

Role Description

Kimchi is the AI platform inside CAST AI, focused on building the execution layer where agents perform real work. We are hiring for roles that involve:

• Coding agents, agent runtimes, orchestration systems, and reliability engineering.
• Building on our inference layer, which includes multi-model inference with intelligent routing and an OpenAI-compatible API.

Qualifications

• Experience using AI coding agents in real work environments.
• Strong proficiency in TypeScript or Go, with comfort moving between them.
• Ability to think in harness terms and diagnose agent failures.
• Experience driving features end-to-end: design, build, ship, measure, iterate.

Requirements

• Experience with AI coding agents beyond demos.
• Strong TypeScript or Go in production.
• Understanding of harness concepts and agent context management.
• Ability to manage agent memory and context effectively.

Responsibilities

• Build and evolve the agent harness, including hooks and permission gates.
• Own long-horizon execution with multi-session task completion.
• Architect planner/executor/evaluator pipelines.
• Manage agent memory and context for state persistence.
• Own the harness surface, including CLI and TUI integrations.

What success looks like (after 6 months)

• Shipped at least one major harness feature end-to-end.
• Added constraints to AGENTS.md based on observed failures.
• Improved a measurable reliability metric.
• Formed strong opinions about the harness's effectiveness.

Benefits

• Competitive salary (€6,500 - €9,000 gross, depending on experience).
• Flexible, remote-first global environment.
• Collaboration with a global team of cloud experts.
• Equity options.
• Fast-paced workflow with quick feedback.
• 10% of work time dedicated to personal projects or self-improvement.
• Learning budget for professional development.
• Annual hackathon to spark new ideas.
• Team-building budget and company events.
• Equipment budget for necessary tools.
• Extra days off for work-life balance.

Company Description

This is a location-specific opportunity. We are currently accepting applications from candidates residing in the following European countries: Bulgaria, Croatia, Estonia, Greece, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia, Slovenia, and Ukraine.

*As part of our standard hiring process, a background check may be conducted at the final stage of recruitment through our third-party provider, Checkr.

*Please note that Cast AI does not provide any form of visa sponsorship/work permit.