Senior Backend Engineer (Node.js)

About Us
Scrambly is one of the fastest-growing adtech startups in the world, featured in the AppsFlyer Performance Index and Singular ROI Index in just 3.5 years.

We’re growing 250%+ YoY across revenue, team, product, and technology — fully bootstrapped and profitable.

We’re building the future of app discovery: a reward-powered alternative to the App Store and Google Play. Our loyalty-driven ecosystem connects millions of users with the world’s top apps and delivers unmatched, ROI-focused growth for mobile advertisers.

Our mission is to build a true alternative to traditional app stores — fueled by rewards and data — and create a new, performance-first growth engine for mobile app advertisers.

About the Role
We are looking for a Senior Backend Engineer to join the team building the core systems behind Scrambly. In this role, you will work across two key areas: user-facing product systems, solving complex scalability challenges for a platform serving millions of users globally; and the internal platform, covering admin systems, tooling, and back-office automation that power our operations team.

Your focus will be on writing robust, high-performance code and bridging the gap between product requirements and technical reality. You will work within a modern tech stack to ensure our systems remain fast, reliable, and easy to maintain as we grow.

Key Responsibilities

• Design & Implementation
  • Design, build, and maintain high-performance, scalable backend services and APIs using Node.js (NestJS)
  • Write clean, maintainable, and testable code that serves as a benchmark for the team
  • Ensure seamless integration between backend services and frontend applications
• Architecture & Technical Strategy
  • Propose and implement architectural improvements for core systems
  • Design complex features with a focus on long-term scalability, extensibility, and maintainability
  • Apply best practices for distributed systems and RESTful API design
• Mentorship & Code Quality
  • Champion high code quality and engineering best practices across the team
  • Mentor other engineers through constructive code reviews, technical guidance, and pair programming
  • Foster a culture of technical curiosity and continuous improvement
• Performance & Infrastructure
  • Monitor system performance, identify bottlenecks, and proactively resolve reliability issues
  • Collaborate with DevOps to ensure smooth CI/CD pipelines, deployments, and infrastructure reliability
  • Work with containerization and orchestration tools to manage application lifecycles
• Cross-functional Collaboration
  • Work closely with Product, Design, Frontend, and QA teams to deliver high-quality features
  • Translate product requirements into robust technical specifications
  • Communicate technical constraints and trade-offs clearly to non-technical stakeholders

Requirements

• 5+ years of software engineering experience, with a strong focus on backend development
• Strong proficiency in Node.js and modern frameworks like NestJS
• Excellent system design skills and a solid understanding of backend architecture, RESTful APIs, and distributed systems
• Experience with cloud platforms (GCP preferred; AWS or Azure acceptable), containerization (Docker), and orchestration/IaC (Kubernetes, Terraform, Helm)
• Proficiency with relational (e.g., PostgreSQL), NoSQL (e.g., Redis) databases, and message queues (e.g., RabbitMQ, GCP Pub/Sub, Redis Pub/Sub)
• Hands-on experience with React, capable of implementing basic UI features for internal tools independently
• Strong communication and collaboration skills, comfortable working in a fast-paced team environment
• English: Upper-Intermediate or higher (B2/B2+, written and spoken). You need to be able to communicate clearly in English to work effectively in an international team and participate in architectural discussions

Nice to Have

• Experience in a B2C startup that has scaled to millions of users
• Basic proficiency in Go; able to read, write, and maintain basic Go services without starting to learn from scratch

What We Offer

• Work on systems where performance optimizations translate to immediate user impact for millions of users
• A culture of code reviews, knowledge sharing, and mentorship where the best idea wins
• A fast-paced environment where your code quickly translates into real user value
• We value the stability and value of what you ship, not just the number of lines of code
• Flexible, remote-friendly working environment
• 15 days of paid vacation
• 5 days of paid days off
• 5 days of paid sick leave
• Maternity/Paternity leave
• National holidays based on your country of stay