Mid-Senior Agent Harness Engineer (Python & TypeScript) | Poland, Remote

About the Company

Our Client is building the AI coworker of the future.

Integrated directly into Slack and Microsoft Teams, the platform connects with thousands of business tools and executes real work across finance, marketing, operations, engineering, and customer workflows. The vision is ambitious: replace a significant portion of today's fragmented SaaS stack with a single AI-powered teammate capable of completing real business tasks autonomously.

As the company scales rapidly, they are seeking exceptional engineers to help build the core infrastructure powering the next generation of AI agents.

• Location: Poland (Remote)
• Employment Type: Full-Time
• Level: Mid-Senior Level
• Compensation: Competitive Salary + Meaningful Equity
• Work Authorization: Valid Work-Permit for Poland

What You'll Do

Build Agent Runtime Systems;

• Develop and improve agent runtimes
• Design tool orchestration frameworks
• Build memory and context management systems
• Implement verification loops and agent self-checking mechanisms
• Improve reliability and execution accuracy

Ship Integrations;

• Build integrations with business platforms and APIs
• Implement OAuth, webhooks, schema mapping, and data synchronization
• Create reliable workflows that operate on real customer data
• Support integrations across platforms such as: Salesforce, HubSpot, Stripe, Shopify, QuickBooks, Notion, Microsoft Teams, Slack

Infrastructure & Platform Engineering;

• Manage containerized workloads
• Improve scalability and system reliability
• Optimize infrastructure performance and operational costs
• Support high-volume production workloads

Product Development;

• Ship user-facing features directly into production
• Work across backend, frontend, integrations, and deployment systems
• Collaborate directly with founders and product stakeholders
• Own technical surfaces end-to-end

Requirements

• Experience building or significantly modifying AI agents
• Strong Python development skills
• Strong TypeScript development skills
• Experience with agent architectures and orchestration systems
• Experience shipping production software rapidly
• Strong systems thinking and architectural decision-making abilities
• Experience working with APIs, integrations, and distributed systems
• Strong understanding of AI-assisted development workflows

Preferred Qualifications

• Experience building AI agents used in production environments
• Open-source contributions within AI ecosystems
• Experience with developer tooling and automation
• Experience creating custom agent workflows, MCP servers, or CLI tooling
• Infrastructure and DevOps experience
• Experience with Slack or Microsoft Teams applications
• Previous startup or founder experience
• Deep interest in AI systems, evaluation methodologies, and emerging models

What We Offer

• Competitive compensation package
• Meaningful early-stage equity
• Direct collaboration with founders
• High ownership and autonomy
• Opportunity to build core AI technology used by real customers
• Fast product feedback cycles
• Remote-first work environment within Poland
• Exposure to cutting-edge AI systems and infrastructure

If you have already built AI agents, enjoy shipping quickly, and want to work on one of the most ambitious AI products being built today, we'd love to hear from you...