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.

Key Responsibilities
Enterprise experience strongly preferred.
• 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 chance.

📌 #138512 - Backend Software Engineer - Payments (Bengaluru)
🏢 Upwork
📍 Bengaluru