Senior Ruby on Rails Engineer

About Our Client

Weʼre an established fintech company building the next generation of payments solutions. Our Tech Delivery Team owns our payment platform end-to-end, including critical backend systems that process high-volume, low-latency transactions securely and reliably. Weʼre currently looking for a skilled Backend Engineer with strong Ruby on Rails experience to help build, maintain and evolve the core of our payment processing systems.

About the Role

As a Backend Engineer in the Tech Delivery team, youʼll design, build, and maintain the core services that underpin our payments platform. Youʼll be part of a cross-functional team focused on scalability, security, and performance. While Ruby on Rails is a core part of our stack, youʼll also collaborate across services written in other languages and have opportunities to work in Go and/or Java.

Responsibilities

• Design, develop, and maintain backend services primarily using Ruby on Rails
• Write clean, maintainable, and testable code following best practices.
• Participate in code reviews and ensure code quality.
• Troubleshoot and resolve issues in existing software.
• Improve the performance, reliability and observability of ZAI services.
• Collaborate effectively with engineers on product initiatives that span multiple services and languages in our tech stack.
• Contribute to the continuous improvement of software development processes.

Qualifications

• Min 5 years of professional experience in backend development
• Strong, hands-on experience building production systems with Ruby on Rails.
• Solid knowledge of relational databases (e.g., PostgreSQL, MySQL and NoSQL systems.
• Experience building and consuming RESTful APIs.
• Strong problem-solving skills.
• Ability to work collaboratively in a team

Desirable

• Experience with Go and/or Java, or a demonstrated willingness to work in other languages.
• Familiarity with AWS and cloud-native architectures.
• Exposure to high-throughput, low-latency systems.
• Familiarity with CI/CD practices and tools (e.g., BuildKite, etc).
• Experience building distributed systems and working on high-throughput backend services.
• Experience with message-driven architectures (e.g. Kafka, EventBridge, SQS).
• Background in fintech, payments, or other regulated environments