Backend Software Engineer - Payments

Job Description We are seeking a backend software engineer for a remote contract engagement building and operating scalable, revenue-critical payment infrastructure. You will deliver payment features, reduce technical debt, and modernize services while collaborating with engineers, product managers, and partner teams. Enterprise experience strongly preferred. Key Responsibilities - Implement production backend features for payment flows. - Refactor legacy services, improve test coverage, and modernize APIs, including migrations from deprecated APIs. - Deliver clean, well-tested, production-ready code with passing CI/CD pipelines and peer-review approval. - Deliver initiatives within agreed sprint cycles and participate in code reviews, design discussions, and sprint ceremonies. - Clarify requirements with product managers and partner teams and deliver end-to-end solutions. - Produce designs, API specifications, knowledge-transfer documentation, and runbooks for owned workstreams. - Support maintainability and a smooth handoff to the engineering team at the conclusion of the engagement. Qualifications Must-Have Skills - 3+ years of backend software engineering experience. - Experience building and operating production backend services at scale. - Strong proficiency in Java as the primary programming language, with Kotlin and Python as complementary skills. - Hands-on experience with RESTful and GraphQL APIs, microservices, and event-driven systems. - Payments, fintech, or billing domain experience, including gateways, processors, or payment service providers. - Experience writing unit, integration, and contract tests. - Agile/Scrum experience with sprint-based delivery. - Ability to ramp quickly on an existing codebase with minimal guidance. - Git-based version control and code review using GitLab. - Hands-on experience with GitLab CI/CD pipelines. - Relational database experience with MySQL and SQL. - Distributed systems experience with message queues, asynchronous processing, and eventual consistency. - Jira experience for task and sprint tracking. - Experience building end-to-end backend payment flows in production, including charges, refunds, disputes, and webhooks. - Legacy service refactoring or migration experience with regression testing. - Experience resolving production incidents in payment or billing systems. - Experience designing internal APIs consumed by multiple downstream services. - Ability to own feature delivery with minimal supervision and collaborate asynchronously with distributed, cross-functional teams. Nice-to-Have Skills - Experience in a large enterprise engineering organization. - Experience with Spring Boot, Gradle, and service mesh technologies. - PCI-DSS compliance, payment security, or financial data handling experience. - Experience with Datadog observability tooling. - Open-source contributions or a portfolio of shipped payment features. Additional Information Required Tools & Platforms - Java, with Kotlin and Python as complementary languages. - RESTful and GraphQL APIs, microservices, and event-driven systems. - Git, GitLab, and GitLab CI/CD. - MySQL and SQL. - Message queues and asynchronous processing systems. - Jira. Location, Time & Engagement - Candidates must be based in India or a nearby eligible APAC location no more than two hours ahead of or behind India Standard Time (IST). - IST support is required, preferably 10 AM to 7 PM IST. - Remote contract engagement, 40 hours per week. - Expected engagement through March 31, 2027; start date to be agreed. - One opening is available. - This is not currently a contract-to-hire opportunity.