Senior Backend Engineer-Mobile App (f/m/x) - remote

Refurbed; United States; Remote; USD 140,000 - 190,000; Full time

Job summary

refurbed is seeking a Senior Backend Engineer to design and implement scalable backend services powering our mobile app and marketplace. You will ensure backend decisions align with mobile app needs, working in a cross-functional product squad with engineers, product managers, designers and business stakeholders.

You will own core APIs, production monitoring, and integration of third-party services, while upholding high performance and reliability.

Qualifications

• 7+ years of experience designing and building scalable backend services
• Strong proficiency in Go and distributed systems knowledge
• Experience with mobile-app consuming backends and API design considerations
• SQL and relational database design expertise

Responsibilities

• Design, build, and maintain core APIs and backend services powering the mobile app and marketplace
• Own operations and monitoring of production systems
• Advise on backend decisions to fit mobile app constraints across squads
• Integrate third-party systems and APIs into the platform
• Own design and implementation of new features and services
• Promote best practices and standards across engineering
• Document solutions with clear diagrams and comments
• Mentor junior colleagues and onboard new joiners
• Collaborate with engineers, product managers, and stakeholders to deliver value

Skills

Go

Distributed systems

Node.js/TypeScript

SQL

API design

Mobile app integration

Education

Bachelor's degree in Computer Science

Tools

PostgreSQL

Redis

RabbitMQ

gRPC

Kubernetes

Job description

Founded in 2017, refurbed is Europe’s fastest-growing marketplace for refurbished products, active in 23 European countries and having surpassed €2Bn in GMV — all while being profitable. With beautiful headquarters in Vienna, we operate as a remote-first company and have been recognised as a Top DACH Employer by Kununu for four consecutive years.

Our mission is to make sustainable consumption the easy choice by enabling customers to buy products up to 40% cheaper while significantly reducing CO₂ emissions.

If you thrive in an environment that values momentum, ownership, and impact, you’ll feel at home here. We’re a fast-paced, high-performance team that works hard and challenges itself everyday. To enable this high-performance every team member enjoys full autonomy over their location (we’re remote-first).

We are seeking an experienced Senior Backend Engineer (f/m/x) to join our App squad. In this role, you will be responsible for the design and implementation of scalable backend services that power refurbed's mobile app and marketplace. Just as importantly, you understand how a native mobile app consumes those services - so you can guide backend decisions, your own and those of other squads, to fit the app's needs and constraints. You will work as part of a cross-functional product squad, collaborating closely with other engineers, product managers, designers, and business members to deliver robust, reliable, and high-performance solutions that enhance the experience of both our customers and our sellers.

Our technology stack is built on proven, modern, and open-source technologies. On the backend, we primarily use Go, gRPC, PostgreSQL, Redis, and RabbitMQ, with Node.js / TypeScript powering a number of app-facing services. Our mobile app is built in React Native + Expo, and on the web frontend we leverage Vue.js, Alpine.js, and Tailwind CSS. Our infrastructure runs on Google Cloud Platform, orchestrated with Kubernetes, ensuring reliability and scalability at every layer.

WHO YOU ARE:

• You have 7+ years experience designing and building scalable backend services in a modern production environment
• You have strong proficiency in Go and deep understanding of distributed systems and service-oriented architecture
• You are comfortable with JavaScript/TypeScript, or confident you can pick up Node.js quickly - with strong Go fundamentals, we expect the rest to come easily. Existing Node.js experience is a plus.
• You've worked on a team that builds and maintains a native mobile app. You don't need to write native code yourself, but you have real exposure to how mobile apps consume backend services and understand the constraints and caveats they introduce (API design for mobile, versioning and backwards compatibility, release cycles, latency, offline behaviour). You can spot when a backend decision won't fit the app and flag it early.
• You are well-versed in SQL and relational database design
• You have general knowledge of the frontend world, and are able to perform basic tasks in our frontend apps
• You're a self-starter with strong ownership, initiative, and the ability to quickly learn and navigate complex systems
• You're open-minded and communicate with clarity, directness, and respect
• You value humility, are low-ego, and thrive in a collaborative, transparent culture
• You have excellent English skills and you are based in a European time zone.
• You're curious and eager to experiment with new and better ways of developing software, whether it's a new framework, the latest AI tool, or developing a new practice
• A degree in Computer Science (or a related field) or equivalent work experience is desired as it provides a strong foundation for tackling the complex challenges we work on.
• Bonus: you're comfortable operating beyond your own squad - reviewing designs and guiding other engineers whose work touches the mobile app. This role has room to grow into a broader technical leadership scope for the right person.

WHAT YOU'LL DO:

• Design, build, and maintain our core APIs and backend services that power the mobile app and marketplace
• Own the operations and the monitoring of production systems
• Be the mobile-aware voice in backend decisions across squads: review designs and API changes, yours and other teams', to make sure they fit the needs and constraints of our mobile app, and flag caveats early
• Integrate third-party systems and APIs into our platform
• Own design and implementation of new features and services
• Identify best practices and create/suggest standards to be used by whole engineering department
• Documents and demonstrates solutions by developing documentation, flowcharts, layouts, diagrams, charts, code comments and clear code
• Contribute to sustaining refurbed engineering culture by mentoring more junior colleagues and onboarding new joiners
• Collaborate closely with other engineers, product managers, and business stakeholders to deliver …