Microsoft is a large, globally distributed software company whose engineers span many product domains, work across diverse codebases and program in a wide range of languages. As described in Adoption and Impact of Command-Line AI Coding Agents, a study written by Microsoft employees, it sells AI tools, encourages their use, and owns GitHub, the maker of GitHub Copilot CLI.
Activities & Products
For several years before 2026, Microsoft’s employees had access to GitHub Copilot in non-CLI forms — code completion, chat and agent mode in IDEs such as VS Code. In the first half of 2026 its engineers had two sanctioned agentic command-line tools: Copilot CLI, available to Microsoft through a product preview program ahead of its general availability, and Claude Code, which reached engineers along a narrower path — from late 2025, specific divisions and individuals received access through a managed program whose access list evolved over time. The study treats January 5, 2026 as the point around which the company’s broader internal use of these tools took off. Microsoft also ran an internal “Agentic Engineering Day” of demonstrations, tutorials and hands-on sessions on the tools.
Shortly after April 29, 2026, an internal announcement indicated that Claude Code licenses would be discontinued for most engineers in about a month, with affected engineers directed to transition to Copilot CLI. In the company’s telemetry-based study of the rollout, adoption of Copilot CLI spread mainly through visible peer and manager use, and adopters of either tool merged roughly 24% more pull requests than a synthetic counterfactual predicted.
Microsoft organises engineering roles on parallel career-stage ladders — IC for individual contributors and M for people-managers — in which a higher number indicates greater scope and seniority and stages with the same number on the two ladders, such as IC4 and M4, are calibrated as peers.