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Agent Harness Engineer (On-site)

Warsaw💼 Full-time🗓 2026-04-29 → 2026-09-25

Core

Build the runtime and infrastructure for a general-purpose AI agent (Viktor) that executes tasks across thousands of business integrations reliably.

Role type

Senior IC agent harness engineer

Builds

Agent runtime, tool integrations, memory systems, and evaluation frameworks for a general-purpose AI agent

Domain

AI Agents / LLM Infrastructure / Enterprise Integration

Deliverable

production ML models

Required skills

AI agent development, Python, TypeScript, systems design, evaluation frameworks, infrastructure as code, rapid prototyping, debugging at scale

Preferred skills

prior AI engineering experience, open source contributions to AI tooling, founder/early-stage builder experience

Technologies

Python, TypeScript, React, Modal

Responsibilities

Build the agent runtime loop for planning, acting, and verification; compose tools across 3,000+ integrations; develop memory and self-writing skills; implement evaluation systems to catch regressions; ship features to Slack and Teams; fix production incidents end-to-end

Seniority

Senior, hands-on IC

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