Senior Backend Engineer, Payments

This is a fully remote position, open to applicants in United States.

📋 Description

• Design, develop, and manage services related to card processing, refunds, and payment reconciliation.

• Take ownership of processor integrations via a unified connector layer, including onboarding new processors and phasing out old ones.

• Create secure payment pipelines featuring idempotent charge paths, processor timeouts and retries, webhook management, and automated reconciliation.

• Establish audit trails for payments and refunds.

• Address payment-related incidents, conduct root cause analyses, and implement lasting solutions.

• Collaborate with Customer Success on the payments support queue and convert recurring issues into product enhancements.

• Write clean, testable, high-performance code in Kotlin and Java using Spring Boot.

• Design and develop scalable production APIs.

• Refactor and extend services to enhance reliability and maintainability.

• Design and optimize PostgreSQL schemas and fine-tune SQL queries for large data volumes.

• Participate in Agile/Scrum design reviews, code evaluations, and architectural discussions.

• Work closely with product, frontend teams, and Customer Success on billing and payments features.

• Mentor engineers through code reviews and share context to prevent knowledge silos.

⛳️ Requirements

• Over 5 years of experience in building production backend systems.

• More than 2 years working with payment systems in production, encompassing card processing, recurring billing, refunds and reversals, or reconciliation.

• Direct experience with at least one payment processor or gateway API integration.

• Proven experience in designing and managing systems with distributed data at meaningful scales.

• Experience in Agile/Scrum work environments.

• Strong familiarity with Git/GitHub workflows.

• High proficiency in Spring Boot (Java and/or Kotlin).

• Willingness to use Kotlin as the primary programming language.

• Extensive experience with relational databases, particularly PostgreSQL.

• Background in building and maintaining production APIs.

• Working knowledge of idempotency, at-least-once vs. exactly-once processing, retries, and reconciliation patterns for financial transactions.

• Understanding of PCI DSS scope and tokenization practices.

• Experience dealing with financial edge cases, including partial refunds, voids versus reversals, chargebacks, declined transactions, and timezone-sensitive scheduling.

• Ability to translate product requirements into technical solutions effectively.

• Strong skills in problem decomposition and debugging, including handling production incidents.

• Solid foundation in computer science principles and sound engineering judgment.

• Excellent written and verbal communication skills.

• Experience with AI-assisted development tools or a willingness to utilize AI tools daily, including Claude, Claude Code, Cursor, and GitHub Copilot.

🏝️ Benefits

• Competitive salary plus equity.

• Health, dental, and vision insurance.

• Flexible paid time off (PTO).

• Remote-first work culture.

• Access to modern development tools and AI assistants.