Senior Backend Developer (Node.js)

TL;DR

Senior Backend Developer (Node.js): Building and scaling REST APIs and backend services that power a high-traffic walking rewards application with an accent on NestJS, PostgreSQL, Redis, and Google Cloud Platform. Focus on optimizing data access, designing scalable cloud-native infrastructure, and improving reliability for millions of users.

Location: Hybrid role based in Barcelona; candidates must already live in the city or be ready to relocate to Spain.

Company

A consumer technology product helps millions of users make walking more rewarding, engaging, and consistent.

What you will do

• Design, build, and maintain robust REST APIs and backend services with NestJS.
• Architect and optimize PostgreSQL data models, schemas, indexes, and queries.
• Implement Redis caching strategies and improve application responsiveness at scale.
• Deploy and operate cloud-native backend infrastructure using Google Cloud Platform services such as Cloud Run, Pub/Sub, and Cloud Storage.
• Collaborate with mobile, product, and data teams to define API contracts and deliver reliable features.
• Monitor performance, participate in code reviews and agile ceremonies, and contribute to technical strategy and documentation.

Requirements

• 6+ years of backend development experience, preferably in product-driven, high-traffic environments.
• Strong TypeScript and Node.js skills, including solid experience with NestJS.
• Deep knowledge of PostgreSQL and hands-on experience with Redis.
• Experience with Google Cloud Platform or cloud-native deployment patterns.
• Experience with Prisma ORM or a similar ORM, plus understanding of clean architecture, design patterns, and SOLID principles.
• Fluent English required; candidates must be based in Barcelona or ready to relocate to Spain.

Nice to have

• Experience working in an agile, fast-moving startup environment.
• Experience with high-traffic consumer applications and analytics tools such as BigQuery, Mixpanel, or Metabase.

Culture & Benefits

• Hybrid working culture with international flexibility.
• Private healthcare, meal vouchers, and a wellness allowance.
• Four additional company holiday days.
• Friday team lunches, company events, and offsites.
• Ownership-driven culture focused on collaboration, data-informed decisions, empathy, and continuous improvement.

Hiring process

• HR call followed by a hiring manager interview.
• Practical assessment and technical interview discussing the assessment.
• Final culture-fit interview with the CTO and other team members.