Senior Full-Stack Engineer (Next.js)

About Ruby Labs: Ruby Labs is a leading technology company that creates and operates innovative consumer products, driving the future of consumer-led platforms across the health, education, and entertainment industries. We build and scale highly profitable Direct-to-Consumer (D2C) subscription platforms used by hundreds of thousands of active customers globally, processing large volumes of high-traffic data and revenue every single month. Well beyond the standard MVP stage, our products are battle-tested in production and scaling rapidly, providing an ambitious environment for engineers who want to make a global impact.

Position Overview

We are seeking an autonomous, pragmatic, and highly driven Senior Full-Stack Engineer to take meaningful technical ownership of complex product areas under a permanent, full-time remote Independent Contractor Agreement. Operating within a high-velocity engineering culture aligned with the Central European Time (CET) zone, you will run complex features end-to-end without waiting for structured tickets or extensive product specifications. Shifting entirely away from legacy software maintenance, low-stakes application scripting, or comfortable line-by-line coding routines, you will drive architectural decisions and feature iteration under real-world pressure. This position requires a full-stack authority with 4+ years of production experience who builds scalable web systems natively using Next.js frameworks, optimizes relational data querying inside PostgreSQL environments, establishes automated CI/CD deployment channels, and collaborates directly with product teams to ship high-quality customer features in days rather than weeks.

Key Responsibilities

• End-to-End Product Ownership: Lead the complete engineering lifecycle of complex product modules, spanning initial structural architecture decisions, clean implementation, production deployment, and post-launch optimization natively utilizing Next.js mechanisms.
• Technical Strategy and Scope Navigation: Drive technical direction independently within your assigned area, collaborating directly with Product Management and leadership to push back on unrealistic scope, flag timeline risks, and offer better engineering alternatives.
• High-Traffic Performance Tuning: Guarantee the absolute reliability, speed, and scalability of web applications, implementing data caching strategies (such as Redis) and optimizing PostgreSQL schemas and queries.
• Engineering Excellence and Culture: Formulate and improve rigorous CI/CD automation pipelines and development workflows, leading peer code reviews to raise overall maintainability and software standards across the organization.
• Team Mentorship and Growth: Provide technical mentorship to mid-level engineers to elevate the engineering bar, while contributing actively to the onboarding and technical interview process for incoming talent.
• Production Triage and Monitoring: Actively monitor, debug, and troubleshoot live production errors, ensuring minimal regression patterns across high-volume transaction setups.

Required Skills & Qualifications

• A minimum of 4+ years of professional history building, scaling, and maintaining full-stack web applications within a high-tempo production environment.
• Mandatory Next.js App Router Expertise: At least 2+ years of direct, practical production experience leveraging the Next.js App Router framework coupled with TypeScript and modern frontend architectures.
• Proven capacity to manage features autonomously from vague, loosely defined specifications to production-ready deployments.
• Strong relational database proficiency using PostgreSQL, including deep data modeling, schema design, and query performance optimization.
• Solid understanding of application caching strategies (Redis or equivalent) along with active version control workflows using Git and Docker containers.
• Excellent communication strengths, demonstrating full confidence explaining complex technical systems clearly and providing pragmatic engineering feedback to non-technical stakeholders.
• Location Context: Position operates under remote geographic guidelines open to qualified full-stack developers based in Ukraine, Bosnia, Georgia, Kazakhstan, Moldova, North Macedonia, Serbia, or Turkey (retaining ±4 hours compatibility with Central European Time).

Preferred Strategic Indicators (Nice to Have)

• Experience working with headless CMS architectures, with a specific preference for Payload (or Strapi, Sanity, Contentful).
• Prior history building or debugging subscription payment systems and billing infrastructure (such as Stripe, Paddle, or Recurly), including dunning, cancellation flows, and retry logic.
• Experience with close-to-the-metal PDF rendering, data manipulation, or editor libraries (such as pdf-lib, PDF.js, or react-pdf).
• Background operating inside D2C SaaS environments, rapid conversion rate optimization (CRO) testing, or performance marketing engineering loops.
• Familiarity with server-side Node.js frameworks like Nest.js.

What We Offer

• Flexible Independent Contractor Structure: A highly autonomous, flexible agreement offering significant entrepreneurial freedom and regional tax advantages.
• Absolute remote work empowerment, giving you the control to optimize your calendar and workspace.
• Unlimited Paid Time Off (PTO): Comprehensive unlimited vacation days to recharge your well-being, supplemented by fully paid regional national holidays.
• Top-tier hardware infrastructure provisioning, featuring a company-provided Apple MacBook delivered directly to your home office.
• A transparent, elite engineering platform where high effort is matched with rapid career advancement, expanded responsibility, and financial success.