Founding AI Harness Engineer — Remote (Eastern Europe)

Heyjared; Polska; Hybrid; PLN 777,000 - 1,166,000; Full time

Job summary

Heyjared is seeking a Founding Harness Engineer for Eastern Europe. You will build the harness that enables Jared's AI coworker to act as a proactive, careful teammate, managing context, tools, and approval gates.

You will ship production-ready agents, design system prompts, and craft robust evaluation harnesses while collaborating with the founder and early users from Serbia, Poland or other Eastern European countries.

Qualifications

• Shipped agents that use tools in production.
• Hands-on system prompt design improved through testing.
• Strong regression/eval harness experience.
• Understanding safe tool execution and data risk.
• Ability to own broad problems from prototype to production.

Responsibilities

• Design and build the agent runtime: how Jared gets context, decides when to speak, chooses tools, waits for approval, completes work.
• Write and iterate system prompts: proactive without noisy or reckless
• Build eval and regression tests around real tasks, tool use, failure cases. Prompt changes are code: test them, catch regressions
• Make behaviour reliable across long-running work, interruptions, retries
• Build safe boundaries: approval gates, multi-tenant data separation
• Work directly with the founder and early users

Skills

Agent development

Tool integration

System prompts design

Regression testing

Safety & data risk

Prototype to production

Founding team mindset

Tools

Production tools

Job description

Heyjared is seeking a Founding Harness Engineer for Eastern Europe. You will build the harness that enables Jared's AI coworker to act as a proactive, careful teammate, managing context, tools, and approval gates.

You will ship production-ready agents, design system prompts, and craft robust evaluation harnesses while collaborating with the founder and early users from Serbia, Poland or other Eastern European countries.