Staff Software Engineer, Frontend Infrastructure

Slack•Seattle, WA

About The Position

Slack is looking for a Staff Frontend Infrastructure Engineer who views the browser as a complex distributed system. While most frontend roles focus on building user-facing features, this role is dedicated to building the Web Platform—the architectural foundation that enables hundreds of engineers to ship high-performance, reliable code to millions of users. You won't just use frameworks; you will optimize their internals, architect the network layers that sync real-time data, and lead the technical strategy for our application state and data flow. You will work with real-time data streams and author code that sets the standard for quality and velocity, establishing patterns that other teams can effectively contribute to. You will collaborate closely with Product and Design to influence the product roadmap and drive the technical vision for our large (and growing!) user base.

Requirements

7+ years of experience writing client-side code (React + Typescript) for modern web applications at scale.
Development at Scale: Experience working in a large-scale, shared codebase with hundreds of contributors, where you have successfully established patterns that allow other teams to contribute effectively without friction.
Strategic Architecture: Expertise in building complex systems and tooling, with the ability to lead technical design that guides the best decisions across the team.
Business Alignment: Exceptional communication skills with the ability to tie technical infrastructure your work succinctly to company goals like performance, reliability and developer velocity. Routinely and facilitates dialogue between junior and senior members to surface blockers.
Technical Breadth: Experience investigating and improving performance (e.g. Core Web Vitals, memory management) and reliability (e.g. Websocket resilience, request handling), with a track record of developing novel applications of existing frameworks or building new tools that enable "self-serve" models across engineering teams.
Self-Awareness: A commitment to proactively offering regular, constructive feedback and gracefully receiving it to improve yourself and the team culture.

Nice To Haves

Experience contributing to the engineering reputation externally (e.g., blog posts, speaking at conferences, open source contributions).
Experience navigating large-scale framework upgrades (e.g. React 19) in a production environment.
Experience with WebRTC, WebSockets, Local Storage and Service Workers at extreme scalerelated web APIs.
Experience in fast-paced and dynamic product development environments.

Responsibilities

Strategic Leadership: You will influence the product roadmap in collaboration with Product, Design, and Engineering, while helping to drive team-wide goals, planning, and feedback cycles.
Technical Standards: You will author code that sets the standard for quality and velocity for the team, frequently establishing patterns that other teams can effectively contribute to.
Navigating Ambiguity: You will thrive in ambiguity, often identifying and offering solutions to problems, like framework migrations or rendering bottlenecks, that are not yet evident to the leaders who presented them.
System Health: You will efficiently use and improve our infrastructure to reduce cost, load, downtime, and incidents, navigating trade-offs to ensure the healthy progress of the codebase. This includes optimizing the “Boot” lifecycle and managing API reliability through request deduplication and rate-limiting
Mentorship & Culture: You will build a safe space for learning and serve as a skilled and trusted mentor to engineers across the organization, developing the ability to coach new leaders rather than just individual contributors.
Cross-Functional Execution: You will collaborate with teammates across engineering to identify, define, and solve strategically important initiatives, acting as a leader in communication to de-escalate conflicts and drive consensus.