Senior Fullstack Engineer (Moderation)

Description

The company is the company, which provides real-time chat, video, activity feeds and AI moderation to over 1 billion end users across more than 4,000 apps, including Strava, Bumble, eBay and Patreon. The platform handles billions of API requests a month and supports applications with millions of concurrent users, with a focus on high reliability, low latency and a strong developer experience.

The role is on the five-person Moderation team, which builds the product customers use to detect, review and act on harmful content. The company has offices in Boulder, Amsterdam, Skopje and Toronto, has 140+ employees from 37 nationalities, and is a Series B company. It is backed by Felicis Ventures, GGV Capital, 01 Advisors, Techstars and Arthur Ventures, with angel investors including Dick Costolo (ex-CEO of Twitter), Olivier Pomel (CEO of Datadog), Tom Preston-Werner (co-founder of GitHub) and Nicolas Dessaigne (co-founder of Algolia).

The team is small and the product has grown quickly, so the backend has accumulated a lot of cleanup, refactoring and simplification work. The role leans backend, and the frontend engineers own the moderation dashboards. The company is a startup, so expect no fixed playbook, end-to-end ownership, and some work outside your title. The company is casual and transparent, focuses on ownership and quality, and keeps management hands-on with little middle management.

Responsibilities

• Own the backend of the AI Moderation product, building new capabilities and making the Go services behind them cleaner, faster and more reliable.
• Design and ship Go services from database schema and API endpoints through to production, including the new AI moderation flow.
• Refactor existing moderation services, pay down technical debt, simplify code paths and raise test coverage.
• Strengthen alerting and observability, and fix scaling and latency problems in the moderation pipeline.
• Maintain and extend the AI and moderation provider integrations that plug into the pipeline.
• Find root causes of defects and take part in on-call, with a focus on North American hours.
• Troubleshoot issues directly with customers and feed what you learn back into the roadmap.
• Ship React changes alongside the frontend engineers when a feature spans the stack, and review peers' code.
• Work with the team lead, the other Toronto engineer, Infrastructure, Customer Success and Support, and customers' trust and safety and engineering teams.

Requirements

• You are a backend engineer at heart and are comfortable taking on frontend work when a feature needs it.
• You like leaving code better than you found it and would rather simplify a service than add another layer.
• You take ownership of problems end to end, including production issues and customer conversations.
• This role is a poor fit if you want a pure frontend job, a large team with a fixed process, or no on-call. The team is small, the product moves fast, and North American coverage is part of the job.
• 6+ years of professional software engineering experience, mostly on the backend.
• Solid backend experience in Go, Python or a comparable language, and a willingness to work in Go. The company runs a 10-week internal Go onboarding programme.
• Experience designing REST APIs and relational data models, ideally on Postgres, and working with Redis.
• A track record of shipping features used at scale and of refactoring and improving live production systems.
• Working knowledge of React and TypeScript or JavaScript.
• Experience with automated testing across client and server code.
• Comfort working with customers and handling production incidents.
• Bonus: exposure to trust and safety, content moderation or policy enforcement products.
• Bonus: professional experience with Go.
• Bonus: experience with GCP or another major cloud provider.
• Bonus: experience integrating LLM or ML-based services into production systems.
• Bonus: message queue experience.
• Bonus: full-text search experience.
• Bonus: open-source contributions.

Conditions

Full-time role, hybrid with 3 days a week in the Toronto co-working space.

Stack: Go, Postgres, Redis and React on GCP, with Claude, Cursor and ChatGPT Codex as everyday tools.

Base salary of CAD 130,000 to 190,000 per year.

Equal-opportunity employer.

Benefits

• 20 days of PTO in your first year, rising to 24 days from your second year.
• Company equity.
• Extended healthcare and dental benefits.
• Long and short-term disability, and life insurance.
• Fitness stipend and a MacBook Pro.
• Learning and development budget.
• Chances to attend or present at global conferences and meetups, and to visit the Boulder and Amsterdam offices.
• Work on open-source projects.