Senior Backend Engineer (Node.js)

Scrambly; Finland (MN); On-site; USD 140,000 - 180,000; Full time

Benefits offered by this job

Performance impact

Code reviews culture

Mentorship and growth

Fast-paced environment

Job summary

Scrambly is seeking a Senior Backend Engineer to build the core systems powering our adtech platform for millions of users worldwide. You will design scalable Node.js services (NestJS), develop robust RESTful APIs, and collaborate with Product, Design, and QA to deliver reliable software that fuels growth.

You will mentor engineers, optimize performance, and work with cloud, containers, and IaC tools (GCP/AWS/Azure, Docker, Kubernetes, Terraform, Helm).

Qualifications

• 5+ years of software engineering experience with a backend focus.
• Proficiency in Node.js and NestJS.
• Strong system design knowledge and experience with distributed systems.
• Experience with cloud platforms (GCP preferred; AWS or Azure acceptable).
• Docker and orchestration with Kubernetes; Terraform/Helm.
• Proficiency with relational databases (PostgreSQL) and NoSQL (Redis).
• Experience with messaging systems (RabbitMQ, Pub/Sub).
• Frontend autonomy with React for internal tools.
• Excellent communication in English in an international team.

Responsibilities

• Architecture & Development: Design, build, and maintain scalable Node.js RESTful APIs and distributed systems.
• Quality & Mentorship: Mentor engineers through code reviews and pair programming to promote clean, testable code.
• Infrastructure & Performance: Monitor reliability, optimize CI/CD pipelines with DevOps collaboration.
• Cross-Functional Collaboration: Work with Product, Design, and QA to translate requirements into robust specs.

Skills

Backend development

System design

RESTful APIs

Distributed systems

English communication

Tools

Node.js

NestJS

Docker

Kubernetes

Terraform

Helm

PostgreSQL

Redis

RabbitMQ

GCP Pub/Sub

Redis Pub/Sub

React

Job description

About The Company

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

• Architecture & Development: Design, build, and maintain highly scalable Node.js (NestJS) RESTful APIs and distributed systems. Ensure seamless frontend integration and drive long-term architectural improvements.
• Quality & Mentorship: Champion clean, testable code standards and foster a culture of technical curiosity by mentoring engineers through code reviews and pair programming.
• Infrastructure & Performance: Monitor system reliability, resolve bottlenecks, manage containerized application lifecycles, and partner with DevOps to optimize CI/CD pipelines.
• Cross-Functional Collaboration: Partner with Product, Design, and QA to translate requirements into robust technical specs, while clearly communicating technical constraints to non-technical stakeholders.

Requirements

• Experience: 5+ years of software engineering experience, with a strong focus on backend development.
• Tech Stack: Strong proficiency in Node.js and modern frameworks like NestJS.
• System Design: Excellent system design skills and a solid understanding of backend architecture, RESTful APIs, and distributed systems.
• Infrastructure: Experience with cloud platforms (GCP preferred; AWS or Azure acceptable), containerization (Docker), and orchestration/IaC (Kubernetes, Terraform, Helm).
• Databases & Messaging: Proficiency with relational (e.g., PostgreSQL), NoSQL (e.g., Redis) databases, and message queues (e.g., RabbitMQ, GCP Pub/Sub, Redis Pub/Sub).
• Frontend Autonomy: Hands-on experience with React, capable of implementing basic UI features for internal tools independently.
• Collaboration: 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

• Scale: Experience in a B2C startup that has scaled to millions of users.
• Additional Stack: 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.