We're looking for a Senior Backend Developer (Elixir) to join a global healthcare organization's engineering team, working on a business-critical payment platform that manages donor compensation in the U.S.

You'll design, develop, and maintain secure and reliable payment solutions, build integrations with external payment providers, and contribute to platform modernization.

This role is ideal for an experienced backend engineer who enjoys solving complex financial transaction challenges and building scalable, high-quality systems.

Must Have

• 5+ years of software development experience, with strong backend engineering skills and hands-on experience with Elixir and AWS.
• Experience building payment or financial transaction systems, including payment gateways, ACH transfers, prepaid card APIs, or payment processor integrations.
• Solid understanding of financial transaction integrity, including idempotency, exactly-once processing semantics, and reconciliation.
• Experience designing and integrating RESTful APIs, GraphQL, and distributed systems.
• Strong knowledge of relational and non-relational databases, data modeling, query optimization, and transaction management.
• Experience with CI/CD, automated testing, secure coding practices, and cloud-based applications.
• Experience delivering software in regulated or high-reliability environments, with an understanding of security and data protection.
• Familiarity with AI-assisted development tools (GitHub Copilot, Cursor, Claude Code, or similar) and feature flags.
• Advanced English skills.

What You'll Do

• Design, build, and maintain backend services for a payment platform using Elixir and AWS.
• Develop payment processing features, transaction management workflows, and integrations with external payment providers.
• Implement reliable financial transaction logic, including payment reconciliation, exception handling, and safeguards against duplicate processing.
• Build and maintain secure APIs connecting payment processors, prepaid card networks, and enterprise systems.
• Write clean, maintainable, and well-tested code, following security and compliance standards.
• Troubleshoot production issues, optimize performance, and improve system reliability and observability.
• Contribute to automated testing, code reviews, technical documentation, and production support.
• Collaborate with engineers, technical leads, and product teams to improve and modernize the platform.

Why Apply?

• USD Compensation
• Paid time off
• Meaningful impact: Work on a business-critical platform supporting real financial transactions and donor compensation.
• Interesting technical challenges: Solve complex problems involving payment reliability, transaction consistency, security, and integrations.
• Relocation opportunity (Costa Rica)