Jobs and Careers

Senior Full-Stack Engineer

European UnionRemotefull_timeVerifiedPosted 24 Dec 2025

About the role

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. Learn more about our story at: https://rubylabs.com/about-us/

About the role

We’re looking for a Senior Full-Stack Engineer to help build and scale a modern web platform using Next.js and Fastify. You’ll take ownership of complex features across the stack, contribute to architectural decisions, and ensure high standards for performance, security, and reliability.

You’ll work closely with product and analytics teams to implement data-driven improvements, integrate analytics, and run A/B tests that enhance the user experience. The role also involves researching and adopting new technologies, including AI-driven solutions, to continuously improve both the product and development workflows.

As a senior team member, you’ll mentor other engineers, promote best practices, and clearly communicate technical concepts to a wide range of stakeholders. This role is ideal for someone with a strong product mindset who enjoys building scalable, high-quality systems end to end.

Key Responsibilities

FullStack Development: Take an active, hands-on role in developing complex features and modules using Next.js for the frontend and NodeJS for the backend.
Quality Assurance: Enforce best practices in coding, testing, caching, and performance monitoring to ensure a robust and scalable application.
Security: Design and implement comprehensive security measures at the application, infrastructure, and data levels.
Analytics & Optimization: Collaborate closely with the product team to integrate analytics systems and conduct A/B tests to enhance the user experience.
Innovation: Research and integrate emerging technologies, particularly AI-driven solutions, to improve the product and streamline development workflows.

Qualifications

Next.js: A minimum of 2 years of active, commercial experience with Next.js (v14.x/v15.x). Must have worked on at least two recent projects where Next.js was the primary frontend framework.
NodeJS: Deep knowledge and at least 3 years of hands-on experience with a modern framework such as NestJS, Fastify, or Hono. A clear understanding of their architectural trade-offs is required.
Databases: Strong proficiency with PostgreSQL and/or Supabase, including query optimization and schema design.
ORM: In-depth, practical knowledge of Prisma or Drizzle ORM, with experience in building complex queries and managing migrations.
Caching: A profound understanding of caching strategies (e.g., in-memory, distributed cache, CDN) and the ability to apply them effectively to optimize performance (e.g., using Redis).
Docker: Full proficiency with Docker for creating, managing, and deploying containerized applications. Experience with docker-compose is essential.
Workers & Queues: Understanding and practical application of background workers and message queues (e.g., BullMQ, RabbitMQ) for handling asynchronous tasks.
Security: Proven experience in building secure systems, including protecting against common vulnerabilities (OWASP Top 10), configuring Content Security Policy (CSP), CORS, securing APIs, and hardening hosting environments.
Analytics & A/B Testing: Experience working with analytics tools (e.g., Google Analytics, PostHog, Mixpanel) and platforms for A/B testing.
Mentorship: A genuine passion for teaching, sharing knowledge, and helping team members grow professionally.
Communication: Excellent communication skills, with the ability to articulate complex technical concepts clearly to both technical and non-technical stakeholders.
Product Mindset: The ability to understand business objectives and translate them into technical solutions that deliver real value to users.