Sr. AI Software Engineer - Agent Harness (AI)

TL;DR

Sr. AI Software Engineer - Agent Harness (AI Engineering): Building and optimizing the agent harness—including context management, tool calling, and agent loops—for hybrid local and cloud AI systems with an accent on efficiency and security. Focus on designing agent planning, implementing multi-model abstractions, and solving complex concurrency and memory challenges.

Location: Hybrid (US: Santa Clara, Phoenix, Folsom, or Hillsboro)

Salary: $195,200 - $361,200 USD

Company

hirify.global is transforming AI into something safer and more trustworthy by building agentic AI that combines local and cloud hirify.globalligence to keep data private and costs low.

What you will do

• Design and build the agent loop, focusing on planning, tool invocation, observation handling, and termination.
• Implement tool integrations including file I/O, terminal/shell execution, web, and MCP servers.
• Develop context management systems to handle windowing, summarization, and long/cross-session memory.
• Create a model-agnostic harness to ensure local and cloud models are swappable behind a single abstraction.
• Design and implement security mechanisms for agent operations.
• Enhance observability through tracing, replay, and reproducible agent sessions.

Requirements

• BS/MS in CS, EE, Math, or a related STEM field.
• 8+ years of software development experience.
• Strong command of Python, TypeScript, Go, Rust, or C++.
• Expertise with async, concurrency, and process/subprocess management.
• Experience with projects that invoke external tools or APIs in a loop and manage failure modes.
• Must be based in the US and eligible for the hybrid work model.

Nice to have

• Experience with agent frameworks, tool/function calling, or MCP.
• Experience building developer tooling, CLIs, or IDE-adjacent products.
• Familiarity with sandboxing, containerization, and safe code execution.
• Contributions to open-source agent or LLM tooling.
• Experience with agent security.

Culture & Benefits

• Comprehensive total rewards package including competitive pay and stock bonuses.
• Generous health, retirement, and vacation benefit programs.
• Hybrid work model allowing a split between on-site and off-site work.
• Opportunity to work on frontier agent architecture and hybrid model routing.