Senior Full-Stack Developer (Next.js) - Ruby Labs

About Us

Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us.

About the Role

We are looking for a disciplined, highly autonomous Middle Next.js Developer to build and ship product features for one of our core D2C subscription products. You will own features end to end across a TypeScript monorepo — a Next.js App Router client, a Fastify + Payload CMS API on PostgreSQL, and Cloudflare Workers at the edge — from the moment you receive a task, through breaking it down, estimating, implementing, testing, and observability, to a clean release to production and confirmation that it works for real users.

This is a hands-on engineering role suited for someone who treats production as the standard, not the finish line. Half-tested code, silent failures, and unverified AI-generated output are not acceptable. The codebase is convention-heavy — a layered Feature-Sliced Design structure with strict import rules — and you are expected to work inside those conventions rather than around them. You are accountable for every task you take on and for every area of the product you touch.

Key Responsibilities

Feature Development

• Build features across the Next.js client and the Fastify + Payload CMS backend according to product requirements.
• Write code that follows the team's Feature-Sliced Design layering, naming, and import conventions.
• Ship changes behind feature flags and A/B experiments, fully localized across every supported locale.
• Integrate third-party providers — billing, email/CRM, analytics — over REST APIs and webhooks.

Quality & Reliability

• Cover functionality with unit, integration, and e2e tests at the level the team expects.
• Run a thorough self-review before code review, and review teammates' code with the same rigour.
• Fix bugs and perform root-cause analysis for recurring issues.
• Optimize page and endpoint performance — rendering and caching strategy, database queries, bundle size.

Security & Observability

• Apply secure development practices: schema validation, access control, safe handling of secrets.
• Follow observability practices — structured logging, metrics, and alerts — using existing tooling.

Collaboration

• Break down, estimate, and ship your own tasks to production within the sprint — and stay accountable for them after release.
• Own the areas of the product you work in: their stability, performance, and follow-up fixes.
• Surface requirement clarifications, estimate changes, and risks early and in writing.
• Escalate complex architectural decisions and critical risks to senior engineers.

Qualifications

Must-Have Experience

• 2+ years of commercial React experience, including 1+ year with Next.js (App Router, Server Components, route handlers, rendering and caching strategies) and solid TypeScript.
• Node.js backend experience on a typed HTTP framework (Fastify, Nest, or Express) with PostgreSQL — REST API design, schema migrations, integrations over REST and webhooks.
• Hands-on with the modern client stack: TanStack Query, Zustand, React Hook Form + Zod, Tailwind CSS, and a React component library such as HeroUI, MUI, or shadcn/ui.
• Experience with a code-first headless CMS on PostgreSQL (Payload, Strapi, Directus, or equivalent).
• Testing and delivery discipline: e2e tests (Cypress or Playwright) and unit/integration tests (Vitest or Jest), Git flow, code review, working with CI.
• Daily use of AI development tools (Claude Code or equivalents) with full ownership of code quality, security, and correctness.
• English — B1+

Leadership Attributes

• Owns the outcome — takes a task from requirement to production without waiting to be pushed.
• Maximally autonomous and involved — needs a goal, not step-by-step instructions.
• Verifies before trusting — treats AI output and third-party responses as unproven until tested.
• Structured communicator — surfaces risks, blockers, and estimate changes early.
• Knows the edge of their scope — escalates architectural and security decisions instead of improvising.
• Learns from incidents — fixes the root cause, not just the symptom.

Location & Working Hours

Ruby Labs operates within the CET (Central European Time) zone. Applicants are welcome from locations within approximately ±4 hours of CET.

Benefits

• Remote Work Environment: Embrace the freedom to work from anywhere within the designated timezone.
• Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize well-being.
• Paid National Holidays: Celebrate and relax on national holidays with paid time off.
• Company-provided MacBook: Top-notch Apple MacBooks provided to employees.
• Flexible Independent Contractor Agreement: Benefit from tax advantages, autonomy, and flexibility.

Interview Process

• Recruiter Screening (40 minutes)
• Technical Interview (60 minutes)