Senior Software Engineer (LMTS), Backend – Enterprise Productivity

ABOUT SLACK

Slack is your Digital HQ – a place where work flows between your people, systems, partners, and customers. From Fortune 100 companies to corner markets, millions of people around the world use Slack to connect their teams, unify their systems, and drive their business forward.

Slack breaks down communication silos inside and beyond your organization by bringing teams and tools together around common goals, projects and processes in channels and in Slack Connect. In this digital-first era, Slack's mission is to make people's work lives simpler, more pleasant, and more productive.

A taste of our scale and reach:

• Slack delivers 300k+ messages per second
• 77% of the Fortune 100 use Slack
• 150+ countries have daily active users in Slack
• 200k+ paid customers

The Experience

The Enterprise Productivity team gets orgs authenticated and connected to their productivity suites (Google Workspace and Microsoft 365) and admin tools. Our mission is to close the productivity gap between Slack and Microsoft Teams and unlock deep interoperability with the Microsoft and Google suites, making Slack the clear choice for enterprise customers.

You'll work with product managers, designers, frontend, mobile, and quality engineers, and with partner teams across Platform, Slackbot, and 3P Integrations. We build on PHP/Hack, Java, and MySQL. Expertise in these is a plus, but familiarity with other web languages (Python, Ruby, Go) and relational databases is a fine substitute.

We value simplicity and reliability as properties of a system to be carefully calculated with every decision.

Slack has a positive, diverse, and supportive culture. We look for people who are curious, inventive, and work to be a little better every day. We aim to be smart, humble, hardworking and, above all, collaborative.

What you will actually being doing:

• Design and build backend services and API methods for admin and user authentication and connection flows with Google and Microsoft (OAuth, domain-wide delegation, token management, and permission policies).
• Own and evolve the Admin Productivity Suite backend, including bulk approve/install pipelines, install-state storage, failure handling, and admin analytics.
• Partner with Product, Design, and Frontend to ship features that raise connected-user and DWA adoption, using experiments and data to guide the roadmap.
• Work across team boundaries (Platform, Slackbot, Enterprise Search, 3P Integrations) on shared permission, auth, and connector frameworks, including the evolution from 2.0 connectors toward MCP.
• Contribute heavily to team projects with significant business impact, and own the long-term health of the systems you build.
• Write secure, well-documented designs and work with Security through scoped review.
• Help support and operations triage and resolve production issues.
• Mentor other engineers, review code in depth, and improve engineering standards, tooling, and processes.

You are our person if

You have:

• 6+ years of professional experience building web applications or backend services.
• Experience with PHP/Hack, Java, Python, Ruby, Go, or similar languages.
• Experience with OAuth 2.0/OIDC and authorization models, ideally with Google Workspace or Microsoft 365 / Entra ID integrations (admin consent, domain-wide delegation, Graph or Google APIs).
• Ability to contribute to technical architecture discussions and drive technical decisions within the team.
• Understandable, testable, maintainable code.
• Strong communication skills, including explaining complex concepts to designers, support, and other engineers, and collaborating across teams.
• Solid computer science fundamentals: data structures, algorithms, distributed systems, and information retrieval.
• A related technical degree.

Even Better If

You have:

• Experience with enterprise admin tooling, permission policies, or multi-tenant (Enterprise Grid) architectures.
• Experience with feature flags, experimentation, and data-driven product development.
• Experience with MCP or connector frameworks.