Principal Software Engineer-M365

Principal Software Engineer-M365

United States, Washington, Redmond

Job description

Company and benefits

Job number

200063832

Date posted

Nov 06, 2026

Work site

3 days / week in-office

Travel

Less than 25%

Profession

Software Engineering

Discipline

Software Engineering

Role type

Individual Contributor

Employment type

Full-Time

Overview

Substrate is the data and intelligence platform that enables partner teams at Microsoft to build, deploy, and maintain compliant productivity apps and services with reduced effort and faster time to market. Substrate is one of the key pillars of Microsoft 365 cloud business offerings, used by millions of people across the world, and by hundreds of thousands of commercial organizations and government agencies.

The Core Authentication team is one of the fundamental teams in Substrate. It is responsible for building the authentication and authorization stacks that provide user access into Substrate and inter-service communication within Substrate. The team's mission is to provide secure, reliable and resilient authentication and authorization layers for Substrate and on-premises configurations, including our partners, and to serve as the gatekeeper for core Microsoft 365 resources.

We are looking for a Principal Software Engineer who is passionate about security, technical challenges, debugging and, above all, customer success and satisfaction. Deep experience building secure, large-scale distributed systems is essential; background in modern authentication and authorization is a strong plus.

As a technical leader on the team, you will drive the design and evolution of key parts of the authentication platform, lead complex cross-team initiatives from design through production, and guide the team through critical incidents and root-cause investigations. You will help shape how highly available distributed services of planetary scale securely serve thousands of businesses and millions of users around the world.

The ideal candidate enjoys solving massive scale challenges, mentors and grows others, and embraces the cultural values of inclusion and belonging. Your work will be high impact, with meaningful delivery in less than 6 months. Strong hands-on development skills and a proven track record of technical leadership are highly valued.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.

Responsibilities

• End-to-end ownership of a feature area related to authentication/authorization, responsible for all aspects of designing, developing and deploying the solution. This includes driving its technical direction, leading design and code reviews, and setting engineering standards for the team.

• Lead complex initiatives across Core Authentication and dependent partner teams, working closely with cross-functional discipline contributors (product managers, architects, security engineers, support engineers).

• Apply threat modeling and secure-by-design practices, and ensure solutions meet compliance requirements across commercial, sovereign and government cloud environments. Drive the evolution of the authentication stack, including modern protocols and next-generation cryptography.

• Participate in the on-call