Staff Software Engineer, Community Builders

The Community Builders organization exists to empower anyone, anywhere, to create and steer a thriving community. We do that by making community building intuitive, sustainable, and rewarding. That mission sits at the heart of Reddit's long-term health as a platform: a Reddit with more thriving communities is a better Reddit for everyone, and our job is to make sure the path to "thriving" is one any passionate person can actually walk.

The Engagement team is where we cultivate Reddit's community growth. We help new communities find their audience and build the kind of momentum that keeps them engaged long after the first few posts. We aim to connect users with content and conversations to which they want to contribute, no matter how niche the topic. 

Our north star is thriving communities. These are places where moderators are engaged, members keep returning, and content compounds on itself. Getting communities there requires a content flywheel that surfaces the right guidance and tools at the right moment to speed up organic engagement. We use data, ML-powered signals, and product experimentation to identify and remove every barrier standing between a community and sustainable, self-reinforcing growth.

This is a Growth team. We move with urgency, instrument everything, and treat a missed activation milestone as a signal to learn from, not a number to ignore. If you want to build systems that measurably change the trajectory of tens of thousands of communities, and improve the health of Reddit itself, this is your team.

What you'll do: 

Foster and Guide the Technical Strategy for Growth

Define and accelerate the backend architecture powering the team's core growth levers: the systems that get new communities in front of the right people across feeds, search, and onboarding surfaces, and the infrastructure that drives member participation to build sustained content momentum. You won't just be following a roadmap; you'll shape how we build these systems from the ground up.

🤝Partner With the EM to Cultivate a Growth Engineering Mindset

Growth teams operate differently than platform teams. We prioritize experimentation and iteration, which means sometimes we throw things away to move faster. You'll help the team internalize that operating model: what it means to build for learning, how to balance velocity with reliability, and how to stay rigorous when moving fast.

🤖Scale Impact Through Collaborative Engineering

Just as thriving communities don't succeed in isolation, neither does this team. You'll build and maintain deep partnerships with the engineering teams whose surfaces directly shape community growth: Relevance, Feeds, Search, and beyond. Many of these collaborations will touch ML-powered systems that surface the right communities to the right users. You'll be the bridge that ensures Community Builders has a technical representation for the team and a collaborative influence on their roadmaps.

📊Instrument, Measure, and Iterate

Establish the instrumentation and experimentation foundations that let the team run rigorous A/B tests on growth levers. Translate data from activation funnels, retention curves, and content engagement into architectural choices. Use metrics to make the case for the bets worth taking, and deprioritize efforts that don't meet goals.

🔗Guide Cross-Functional Alignment

Serve as the engineering voice in XFN partnerships with Product, Design, Data Science, and other Consumer platform teams. You'll align stakeholders on technical feasibility and tradeoffs, co-author roadmaps that bridge user experience goals with backend realities, and represent Community Builders Engineering in Reddit-wide technical forums.

⚡Raise the Bar on Engineering Excellence

Advocate for reliability, scalability, and maintainability across a complex, high-scale distributed system. Lead design reviews, establish patterns that the broader organization can learn from, and ensure that moving fast never becomes an excuse for accruing crippling tech debt. You'll define what "great" looks like on this team.

Who You Might Be

• At least 7 years of experience. You’ve steered cross-team projects that solved tangible business problems, rather than just hitting a 'ship' date.
• A strategic partner, not just a technologist. A systems thinker. You see how the code, the product, and the team dynamics all influence each other. You can plan for next year while still helping an engineer through a blocker today.
• You're a mentor who helps other engineers level up. You don't just assign tasks; you help the team work through complex problems more effectively. You're energized by the opportunity to build culture and craft on a team, not just software.
• You're deeply data-informed and logical. You ensure metrics are part of the design process, not just an afterthought in a dashboard. Your architectural directions are traceable back to product and business outcomes, and you're fluent in the language of experimentation, funnels, and retention.
• Comfortable with growth-team ambiguity. You navigate ambiguity with confidence when the goal is clear but the path is not. You're comfortable with growth-team speed—prototyping fast, moving on when the data doesn't back a bet, and keeping the team focused when the plan changes.
• A focus on clear, transparent communication. You can effectively distill complex technical trade-offs for any audience—whether you’re collaborating on a whiteboard with peers or presenting a roadmap review to executive stakeholders.
• Experience with ranking, recommendations, and personalization. You have a proven track record of working on ML-heavy products. You can design the backend architectures, retrieval systems, and inference pipelines required to scale them. You understand the nuances of candidate generation and scoring, and you can partner effectively with Machine Learning engineers to turn model outputs (such as Two-Tower models) into high-impact product features.

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