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Senior Software Engineer/ Principal Software Engineer - Copilot CLI

United States, Washington, Redmond💼 Full-time🗓 2026-06-02 → 2026-09-26

Core

Designing, building, and iterating on agentic systems and high-performance terminal experiences for the Copilot CLI.

Role type

Senior/Principal Software Engineer (Agentic Systems & Terminal UI)

Builds

Copilot CLI, shared agent runtime, terminal UIs, and low-level primitives

Domain

Developer tools, Generative AI, Agentic Systems

Deliverable

production ML models | product features

Required skills

Systems design, performance optimization, debugging complex environments, agentic system evaluation, tool design, agent loop management, quality optimization, product ownership

Preferred skills

Terminal user interface (TUI) development, low-level terminal primitives, open-source project leadership

Technologies

C, C++, C#, Java, JavaScript, Python

Responsibilities

Building and evaluating agentic systems including tool design and agent loops; Designing and shipping performant terminal experiences; Taking ownership of critical product and platform areas; Collaborating across org boundaries to enable other teams; Influencing architecture and engineering standards

Seniority

Senior/Principal, hands-on IC with strategic influence

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