Senior Staff Software Engineer, Client Architecture

Reddit is where 130M+ people a day come to share what they know, ask what they don't, and find their people. Every post, comment, and new format starts with our composers. We're looking for a Senior Staff engineer to be the technical anchor for how people create on Reddit across Web, iOS, and Android.

You'll own the cross-client vision for contribution. That means one shared content model and set of client contracts that all three platforms build against, the performance and reliability engines underneath, and the creation surfaces on top. Our modernized composers are now live on every platform, so the next chapter is growth: making video a first-class way to create, bringing new formats to every user, and using AI to inspire contribution without writing it for people. Every bet has to earn its way through an experiment, so you'll pair architectural judgment with real rigor about what moves the metrics. This is an IC leadership role, partnering directly with Product, Design, and Data Science leadership.

Key Responsibilities:

• Own the cross-client architecture: Define the shared contracts that Web, iOS, and Android build against, including our rich content model, GraphQL schemas, and shared UI primitives. A feature should be designed once and shipped natively everywhere, not built three bespoke ways.
• Make video and media first-class: Set the client architecture for video creation, editing, drafts, and upload, built to survive bad networks, app restarts, and lower-end devices.
• Bring new formats to every user: Establish how new contribution formats plug natively into the composers on every client, including formats that started on our Developer Platform. Unblock execution on the pillar's highest-upside bets.
• Drive experimentation rigor: Partner with Data Science on metric strategy for net-new features. Give engineers a clear recipe for designing and reading experiments, and make the call to iterate or kill when results come back flat.
• Bring AI into contribution thoughtfully: Shape where LLMs help people create, from inspiration at the start of the journey to routing and labeling at the end, while the content itself stays human. Model effective use of AI-assisted development tools, with rigorous judgment over what they produce.
• Lead beyond your team: Write the technical direction and get partner teams to adopt it: client platform, search, feeds, trust and safety, and the developer platform. Negotiate priorities and migrations, and mentor senior and staff engineers on every client.
• Raise the bar on client performance and reliability: Own composer success rates, latency, and crash budgets across platforms. Spot recurring pain points across technical designs and fix them at the root.

Qualifications:

• 10+ years of professional software engineering experience with a proven track record as a Senior Staff Engineer or Principal Engineer on consumer-facing mobile or web client applications.
• Client Architecture Expertise: Deep mastery of modern web architecture (e.g., React, TypeScript, advanced state management) with strong architectural command of native mobile paradigms (iOS/Swift, Android/Kotlin) to define unified client APIs and lead cross-platform engineering standards.
• Domain Expertise: Demonstrated track record of solving hard client-side performance and rendering bottlenecks at scale, building highly interactive features such as zero-latency rich-text editors, asynchronous media processing pipelines, or real-time state synchronization systems.
• Communication: Exceptional written and verbal communication skills. Ability to influence VP-level technical direction and navigate strict tradeoffs between performance, reliability, and business impact without directly managing the engineers involved.
• Demonstrated ability to lead large, cross-functional engineering initiatives that balance technical excellence with aggressive growth targets.

Nice to have:

• Experience with contribution and creation surfaces: composers, editors, rich text and document models, media and video pipelines, offline drafts and sync.
• Browser engine, framework internals, or notable open source contributions.
• Building product surfaces on top of LLMs, including handling latency and unpredictable responses in the UI.

Benefits:

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k with Employer Match
• Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Paid Volunteer Time Off
• Generous Paid Parental Leave