Software Engineer - Payments

About the Role:

We’re looking for a backend-focused Software Engineer to join the Payments Team at Sardine. In this role, you’ll help design and build the APIs, services, and systems that power our crypto onramp and offramp infrastructure. You’ll work across the stack to launch impactful features, drive scalability, and contribute to product and technical direction. This is a high-ownership, high-impact role for an engineer passionate about building reliable systems at scale.

What you'll be doing:

• Build and maintain backend services for our crypto onramp/offramp platform used by hundreds of thousands of users worldwide.
• Design and implement APIs and data pipelines with a focus on high availability, fault tolerance, and zero downtime.
• Collaborate closely with cross-functional teams including product, compliance, and business to launch features end-to-end.
• Work with partners and vendors to deliver seamless payment integrations.
• Help shape the team’s technical roadmap, improve developer tooling, and optimize internal workflows.
• Participate in an on-call rotation and production support to ensure system health and uptime.

What you'll bring:

• 5+ years of proven experience as a Software Engineer specializing in web backend development.
• Proficiency in Ruby (our primary backend language on the Payments Team)
• Experience building APIs, services, and data pipelines.
• Strong sense of ownership, with attention to detail and a proactive attitude toward learning and improvement.
• Experience in frontend development is a plus.
• Proven ability to deliver high-quality, reliable systems in production environments.
• A user-first mindset with strong empathy for customers and their needs.
• Bonus: relevant industry experience, particularly in crypto, fintech or banking, and domain knowledge in fraud prevention or compliance. 
• Proficient in English - from casual chats to formal reports.

Technologies we use:

• Ruby
• Python
• Java
• Terraform
• TypeScript (React + node)
• Golang
• Bigtable
• Postgres / PostgreSQL
• GCP dataflow (apache beam)
• BigQuery