Senior AI Harness Engineer (Agentic Systems)

Stealth Talent Solutions; United States; Remote; USD 180,000 - 260,000; Full time

Benefits offered by this job

Medical benefits

401(k)

PTO

Job summary

Stealth Talent Solutions is hiring for a confidential client with a new AI product division. You will own core harness, ship production code weekly, and set standards for engineering across teams.

This is a hands-on, senior IC role with remote work in the United States, no visa sponsorship, and up to 25% travel to firm offices. You will tackle hard production issues, design the tool layer, and mentor engineers while maintaining production readiness.

Qualifications

• 10+ years of hands-on software engineering and actively writing code today.
• Strong Python skills and ability to build end-to-end features.
• AI agents shipped to production in an enterprise setting and in use.
• Experience running and scaling live systems on cloud platforms (Azure/AWS/GCP).
• Excellent communication with engineers and senior leaders.
• Portfolio or walkthrough showing a system you shipped.

Responsibilities

• Build and own the agent loop, including orchestration and lifecycle.
• Design the tool layer: schemas, argument validation, error handling.
• Own context engineering: what the model sees and does not see.
• Develop the evaluation framework to verify production readiness.
• Add tracing and telemetry to expose agent behavior in production.
• Create integrations around existing harnesses and open standards.
• Set standards for evals, security, and production readiness; mentor teams.

Skills

Hands-on software engineering

Strong Python

AI agents in production

Cloud platforms (Azure, AWS, GCP)

Clear communication

GitHub portfolio / shipped system

Education

STEM degree or equivalent experience

Tools

Azure

AWS

GCP

Claude Code / Cursor / Codex

Job description

Stealth Talent Solutions is hiring for a confidential client: a global professional services firm that has just launched and funded a new AI product division. The division runs like a startup studio, with small product teams building AI agents on top of major SaaS platforms. No billable hours, no utilization targets, no sales quotas. The job is to build great products and ship them.

About the role

Every product team in the division builds on the same shared core: the harness the agents run on. You'll own it. This is a hands-on, individual contributor role at a senior level. You'll write and ship production code every week, take the hardest production issues yourself, and set the engineering standards other teams build on. The problems aren't fully defined yet, and that's on purpose. The right person finds that exciting.

What you'll do

• Build and own the agent loop: orchestration, state and when it stops
• Design the tool layer: schemas, argument validation and errors a model can actually act on
• Own context engineering: what the model sees and what it doesn't
• Build the evaluation framework, so you know it works before it ships
• Add tracing and telemetry, so agent behavior is visible once it's live
• Build integrations around existing harnesses and open standards like MCP, and make build or integrate calls
• Set standards for evals, security and production readiness, and mentor engineers across teams without managing anyone

What you bring

• 10+ years of hands-on software engineering, and you're still writing code today
• Strong Python. You can build it yourself, not only through a coding agent
• AI agents you've shipped to production in an enterprise setting, still in use today
• Experience running and scaling live systems on Azure, AWS or GCP
• A daily, AI-first workflow with coding agents like Claude Code, Cursor or Codex
• Clear communication with engineers and senior leaders
• A GitHub, code portfolio or a walkthrough of a system you shipped
• STEM degree or equivalent experience

Nice to have

• MCP, LangGraph or other agent frameworks
• Founder or early-stage startup experience alongside enterprise work

The details

• Full-time, fully remote in the US, with up to 25% travel to the firm's offices to work with internal teams
• No visa sponsorship. US citizens and green card holders only
• Benefits include medical, 401(k) and PTO