Backend Developer

About the role

Solflare is a Solana self-custody wallet with around 4 million users controlling $20 billion in funds. As a Backend Developer you will build and maintain the backend infrastructure of its applications, ensuring high performance, security and scalability, and work closely with the engineering team on the technical challenges of a crypto wallet app. The company is remote-first but has offices in Zagreb, Belgrade and Novi Sad.

Key responsibilities

• Design and implement scalable, robust backend services and a microservices architecture.
• Develop APIs and integrate third-party services and Solana RPCs.
• Manage databases (PostgreSQL, MongoDB) and ensure data integrity and security.
• Implement caching with Redis and use PrismaJS for database access.
• Deploy and manage applications on DigitalOcean and Google Cloud Platform.
• Use BullJS for background jobs and Cron for scheduled tasks.
• Write unit and integration tests with Jest.
• Collaborate with frontend developers and stay up to date with web and blockchain trends.

Required profile

• At least 4 years of backend development experience focused on web2/web3 technologies.
• Experience with cloud services (Google Cloud Platform, DigitalOcean) and DevOps practices.
• Knowledge of event-based architecture, microservices patterns and scalable system design.
• Nice to have: familiarity with Solana, machine learning concepts applied to real problems, and experience optimising backends for large data volumes.

Required skills

• Node.js, Express.js, PostgreSQL, MongoDB, Redis, PrismaJS
• Jest for testing