We’re turning frontier model capability into a genuinely usable desktop agent product. Beyond the model itself, every system capability that lets the agent understand tasks, organize context, call tools, modify code, record its process, roll back state, and form training feedback belongs to the Harness. You’ll join the Harness team to work on the core of our desktop agent product, landing model capability inside real software-development workflows. Responsibilities Work on core Harness R&D, including the desktop workbench, agent loop, tool calling, context management, plugins/MCP/skills, trace, rollback, and training feedback. Own the design, implementation, testing, and iteration of React / Electron / Python / engineering-infrastructure modules. Design and improve the agent’s code-change pipeline—Git control, diff/patch, staging, branch/worktree, change tracking, conflict handling, rollback, and restore. Collaborate with researchers to analyze the agent’s successes and failures on real tasks, driving the Harness and model capability to evolve together. Dogfood the product on real internal development tasks, continuously surfacing and resolving usability, reliability, and developer-experience issues. Contribute to technical architecture, engineering quality, product experience, and project execution. Qualifications 2+ years of software development experience (flexible for exceptional candidates). Bachelor’s degree or above from a strong university. Solid engineering ability, with deep proficiency in at least one of the following: Frontend. React, TypeScript, state management, complex interactions, desktop UI engineering. Desktop. Electron, main/renderer process communication, local file system, process management, cross-platform desktop apps. Backend. Python, async/process models, tool systems, server-side architecture, testing, and engineering practices. Not all four areas required—but you must be able to independently own one core area and read and collaborate on another. Heavy hands‑on use of AI agent tools for real software development, with intensive experience using agent products. Understanding of LLM/agent fundamentals: LLM APIs, context window, agent loop, tool use, reasoning, planning, MCP, memory, subagents, etc. Good engineering habits—valuing maintainability, testing, observability, safety boundaries, and long‑term evolution cost. Nice-to-haves Capability across multiple of React / Electron / Python / engineering at once. Familiarity with Git internals—object store, index, refs, worktree, patch apply, merge conflict, reflog—or experience building Git-based snapshot, rollback, audit, or sync systems. Experience with AI agents, code assistants, IDEs, developer tools, LLM applications, or automated testing/evaluation platforms. Heavy use of Claude Code, Codex, Cursor, Windsurf, Devin, OpenAI Agents SDK, LangGraph, the MCP ecosystem, or similar products/frameworks. Experience with plugin systems, MCP, LSP, sandboxes, terminal orchestration, trace/replay, workflow engines, or evaluation systems. Personal open‑source work, open‑source contributions, research experience, competition awards, or publications. Able to communicate in English with open‑source or user communities. What We Value We value solid software‑engineering ability first. The Harness is complex, but it ultimately comes down to React, Electron, Python, tool systems, file systems, processes, state, testing, Git control, and user experience. The ideal candidate need not know everything, but must be strong in at least one engineering direction and have real interest in and judgment about agent products. #J-18808-Ljbffr
Harness Engineer [33250] • Menlo Park, CA, United States
Career Launch is hiring for this role and related opportunities.We review candidate profiles across active roles and use resumes/profiles to understand which backgrounds may be a fit.As a Senior Me... Show more
Array Labs builds advanced radar systems to help humanity understand and respond to changes across the physical world.We're launching a coordinated fleet of radar satellites to create a high-resolu... Show more
Retell AI is using first-principles thinking to reimagine the call center with cutting-edge voice AI.Thousands of companies now use Retell's AI voice agents to handle sales, support, and logistics ... Show more
Radar Engineer With Moving Target Indication (MTI) Experience.Array Labs builds advanced radar systems to help humanity understand and respond to changes across the physical world.We're launching a... Show more
At Matic, we're on a mission to recapture that lost time, and we're doing it by revolutionizing home robotics.Our first product, also called Matic, is a Wall-E-esque floor cleaning robot.We've buil... Show more
A cutting-edge technology company based in San Francisco is seeking a Hardware Engineer to develop mechanical components and support electrical testing for their innovative wildfire detection produ... Show more
Career Launch is hiring for this role and related opportunities.We review candidate profiles across active roles and use resumes/profiles to understand which backgrounds may be a fit.As a GTM ENGIN... Show more
Job Title - Power EngineerLocation - Bay Area, CA (Onsite)Contract Duration - 1 year.Work closely with the Design, DV, Implementation team to define low power vectors, generate early and signoff po... Show more
Location: Hybrid, Bay Area (San Mateo, 3x/week).Benefits include: health benefits, 401K, commuter benefits, annual international retreats.Monday morning All Hands at 8am.Series A startup, has PMF; ... Show more
At Dexterity, we believe robots can positively transform the world.Our breakthrough technology frees people to do the creative, inspiring, problem-solving jobs that humans do best by enabling robot... Show more
Experience with client-side MVC/MVVM frameworks and CI/CD pipelines.Expertise in front-end test automation, Git, responsive design, and cross-browser support.Excellent communication and collaborati... Show more
Solving Self-Improving Superintelligence.Today's AI brains are brittle and rigid.At Letta, we're building self-improving artificial intelligence: creating agents that continually learn from experie... Show more
We're looking for seasoned ML Infrastructure engineers with experience designing, building and maintaining training and serving infrastructure for ML research.Provide infrastructure support to our ... Show more
Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power.The com... Show more
At Dexterity, we believe robots can positively transform the world.Our breakthrough technology frees people to do the creative, inspiring, problem-solving jobs that humans do best by enabling robot... Show more
As a GTM Engineer, you'll bridge the gap between growth strategy and technical execution.You will design, build, and optimize the systems and campaigns that fuel acquisition and engagement.Reportin... Show more
ML/LLM systems or large-scale distributed systems.Proven ability to translate product requirements into measurable metrics and test plans.Strong experience with modern data tooling.Hands-on experie... Show more
Manufacturing Diagnostics Engineer.As a Manufacturing Diagnostics Engineer, you will be a part of the team that executes processes to bring up, validate, test, and troubleshoot the Client products ... Show more
Bluejay is building the simulation, evaluation, and observability layer for voice + text AI agents.We work with Fortune 500s, multinational corporations, and high-growth startups to ensure their AI... Show more
Applications EngineerAlembic is pioneering a revolution in marketing, proving the true ROI of marketing activities.The Alembic Marketing Intelligence Platform applies sophisticated algorithms and A... Show more
){kind=logo}
