Senior Backend Software Engineer

About Boku

Boku Inc. is a global leader in mobile-first payment solutions, connecting major brands such as Amazon, Meta, Google, Microsoft, Netflix, and Spotify to millions of consumers lacking credit card access through over 300 local payment options across more than 70 countries. Processing over $10 billion annually, Boku operates worldwide with offices in London, San Francisco, Singapore, and many other countries. The company values diversity and fosters an inclusive workplace.

Role Overview

We are seeking a Senior Backend Software Engineer to join a focused group within our Innovation team, responsible for building brand-new payment products from the ground up. This greenfield role emphasizes designing and developing new services instead of maintaining existing ones, working in a highly autonomous small team reporting to the Head of Product and Engineering.

Key Responsibilities

• Design and develop high-performance, reliable backend services using Java and Spring Boot, ensuring availability above 99.99% and low latency.
• Create and enhance RESTful, gRPC, MCP, and event-driven APIs to handle payment initiation, callbacks, reconciliation, and settlements effectively.
• Implement resilience features including circuit breakers, retry mechanisms, idempotency, and graceful degradation under heavy load with maximum observability.
• Optimize system performance through profiling, load testing, and efficient data access using both SQL and NoSQL databases.
• Collaborate with global and offshore engineering teams, providing code reviews and technical guidance.
• Develop core payment components such as payout engines, AI-driven treasury orchestration, and cash forecasting systems from scratch, within PCI DSS compliance guidelines.
• Contribute to frontend functionality for internal tools and customer-facing dashboards using React, working closely with Product and Design teams.
• (Desirable) Assist integration with real-time FX data sources like Bloomberg feeds and support FX/tresuary monitoring services.
• Incorporate observability from project inception, including structured logging, distributed tracing, and metrics, and participate in defining SLAs and alerting mechanisms.
• Set up CI/CD workflows and container environments (Docker, EKS) adhering to engineering standards.
• Leverage AI-driven tools and workflows, integrating large language model (LLM) features and agentic systems within services where applicable.

Required Qualifications and Experience

• Minimum 5 years of backend software engineering experience, primarily with Java and Spring Boot ecosystem (MVC, Data, Security).
• Proven record building and maintaining high-throughput, highly available payment or financial services platforms.
• Understanding of payment architectures including idempotency, exactly-once delivery, reconciliation, and settlement processes.
• Experience with relational databases (PostgreSQL, MySQL) and messaging platforms like Kafka or RabbitMQ.
• Knowledge of containerized deployments using Docker and orchestration with Kubernetes/EKS plus CI/CD automation tools like GitHub Actions.
• Strong grasp of PCI DSS compliance, secure coding, and sensitive data handling.
• Excellent communication skills and ability to collaborate across distributed teams.

Preferred Skills

• Frontend development with React for internal applications.
• Experience working with Bloomberg FX data feeds or similar real-time financial data sources.
• Background in FX processing, treasury management, or multi-currency settlement systems.
• Familiarity with financial message formats such as ISO 20022 and SWIFT.
• Work history in payment processors, fintech firms, or PSPs covering multiple markets.

AI & Agentic Systems Expertise

• Practical experience integrating LLM-powered capabilities into production, including prompt engineering and API-based structured output handling.
• Design or participation in multi-step autonomous workflows with retries, failure handling, and human oversight checkpoints.
• Knowledge of protocols like MCP that connect AI to internal APIs and external services.
• Proficient use of AI-assisted development tools with critical judgment on their application.

Education

Bachelor’s degree in Computer Science, Engineering, or comparable practical experience is required.

Why Choose Boku?

Join a company impacting billions of dollars in payments worldwide, working within a diverse and innovative engineering culture dedicated to quality and rigorous delivery.