Senior Full Stack Engineer - Unified Experience

About the Role

Support Fanatics Collect’s Unified Experience initiative, building seamless collector journeys across Fanatics Live, Marketplace, Instant Rips, Collections, Topps, and future experiences.

Today a collector can win a card in a live show, rip a pack, buy on the marketplace, and store it all in a vault, but those moments still feel like separate products. Your job is to make them feel like one. That means building the shared surfaces, APIs, and front-end systems that connect experiences built independently, without slowing any of them down.

This is a hands-on senior role with a frontend-leaning center of gravity. You’ll own meaningful slices of the unified experience end to end (UI through API contract), primarily in TypeScript, React, and Next.js on Vercel, with GraphQL as the owned front-to-back contract. You’ll partner with a Staff Backend Engineer, mobile engineers, product, and design.

Why Join Us

Fanatics Collect is growing fast, and the unification work is the highest-leverage engineering investment we have: every new app, drop, and live format gets easier once the shared foundation exists. You’ll work across mobile, web, and internal tools, with real autonomy and a short path from idea to production. Your teammates are passionate about the space and most of them are collectors themselves.

Product Context and Scale

Our surfaces reach millions of collectors across iOS, Android, and web, with live, high-traffic moments (breaks, drops, auctions closing) that make performance, accessibility, internationalization, and reliability non-negotiable. You’ll work across multiple existing products with real users and real data, so migration, backward compatibility, and careful rollout are part of the craft.

First 90 Days

• Ship a meaningful, user-facing piece of the unified experience end to end.
• Build a working map of how Live, Marketplace, Instant Rips, Collections, and Topps fit together today: data models, identity, entitlements, and the seams between them.
• Establish working relationships with the backend, mobile, product, and design partners you’ll depend on.
• Identify one piece of duplicated or divergent logic across surfaces and make the case for consolidating it.

Responsibilities

• Design, build, and maintain fullstack features with a frontend lean: TypeScript, React, Next.js, and Vercel, plus backend work in Python/FastAPI (or equivalent) when the feature needs it.
• Own GraphQL (and related API) contracts for what you ship: schema collaboration, generated types, validation, and compatibility. Treat contract drift as a bug.
• Build scalable, performant interfaces and services on Vercel and AWS.
• Own features end to end: UI, API contract, tests, rollout, and post-launch metrics.
• Build and maintain reusable front-end components, design-system tokens, shared packages/SDKs, and monorepo libraries that multiple apps depend on.
• Ship commerce and cross-surface UX (identity, entitlements, navigation, checkout/offers) that feels continuous across products.
• Make accessibility (a11y), internationalization (i18n), and localization part of how you ship, not a follow-up.
• Ship behind feature flags with instrumentation in place, and use the data to decide what to keep, fix, or cut.
• Prototype quickly with Product and Design when a working demo settles a debate faster than a document.
• Use AI-assisted development tools (Cursor, Claude Code, LLM workflows) to raise throughput, and share what works.
• Write meaningful tests across the stack: Playwright, Vitest or Jest, React Testing Library, visual regression (Chromatic), and Pytest where you touch backend; keep CI trustworthy.
• Maintain Storybook (and Chromatic) for components and interaction specs; use Tailwind alongside the design system.
• Participate in sprint planning, retros, and product strategy; raise scope and sequencing concerns early.
• Mentor through code review and pairing; raise the bar on structure, testing, contracts, and docs.

Requirements

• 5+ years of professional fullstack development, with strong TypeScript, React, Next.js, and Vercel, plus solid backend experience (Python/FastAPI or equivalent) and cloud (AWS preferred).
• Experience owning or co-owning API contracts between UI and backend, ideally GraphQL (schema, codegen/typed clients, compatibility).
• Strong grasp of architectural patterns, API design, and performance tuning, plus the judgment to keep solutions simple.
• Track record of owning features end to end in production, including monitoring, debugging, and iterating on real user behavior.
• Solid front-end fundamentals: responsive UI, accessibility (a11y), internationalization (i18n), localization, and performance.
• Experience with design systems: tokens, shared packages/SDKs, and monorepo multi-app consumption.
• Experience with or clear aptitude for platform-style frontend work across stacks: shared packages, migrations, multiple consumers.
• Experience with state management patterns (React Context, Zustand, Redux, XState, or similar) without over-engineering.
• Strong testing discipline: Playwright, Vitest or Jest, React Testing Library, Chromatic or equivalent, and backend testing (e.g. Pytest).
• Experience with Tailwind and Storybook in real teams.
• Experience with Git and modern CI/CD.
• Comfortable working across domains (backend APIs, customer-facing web, mobile web, internal tools) without dropping threads.
• Clear written and verbal communication with Product, Design, and other engineering teams.
• Experience using or a genuine appetite for AI developer tooling.
• Bachelor’s degree in Computer Science or equivalent practical experience.

Nice to Have

• Integrating or consolidating multiple existing products, including data migrations against live users.
• High-traffic, real-time, or live-event product surfaces.
• Growth engineering or rapid experimentation frameworks.
• E-commerce, marketplaces, or gaming live ops.
• Deep design system or shared component library ownership.
• Passion for collecting, trading, sports, or gaming, and interest in being a user of what you build.

If you like owning problems end to end, care about how software feels and not just whether it works, and want your work used daily by millions of collectors, we’d love to talk.

Ensure your Fanatics job offer is legitimate and don’t fall victim to fraud.  Fanatics never seeks payment from job applicants. Feel free to ask your recruiter for a phone call or other type of communication for interview, and ensure your communication is coming from a Fanatics email address (including @collectfanatics.com).  For added security, where possible, apply through our company website at www.fanaticsinc.com/careers