Senior Software Engineer, Backend

Xenith; Indonesia; On-site; IDR 330,000,000 - 540,000,000; Full time

Job summary

Xenith, a leading B2B fintech platform, is seeking a Senior Backend Engineer to join the Engineering team. You will design, implement, and maintain scalable Go services, focusing on reliability, security, and performance across multi-currency payments.

You’ll integrate with banks and e-wallets, write tests, and mentor junior engineers in a fast-growing environment. You should have a strong system-design background, hands-on experience with PostgreSQL and Redis, and a solid grasp of Agile

Qualifications

• 5+ years backend engineering experience with production-level Go
• Strong system design and architecture skills
• Proficient in test-driven development and code quality
• Excellent communication with technical and non-technical stakeholders
• Experience with Agile development practices
• Security-conscious mindset; familiarity with OWASP

Responsibilities

• Design, develop, and maintain scalable backend services using Go
• Integrate with external payment APIs and handle edge cases
• Write unit and integration tests for new features
• Collaborate with product, infra, and QA to ship high-impact features
• Provide technical leadership through code reviews and mentoring
• Enforce clean architecture, documentation, and observability
• Identify performance bottlenecks and optimize resilience
• Stay up to date with emerging technologies and align with business goals
• Ensure security and proper access control and auditing
• Deploy applications to AWS and support service readiness

Skills

Backend engineering

System design

Test-driven development

Communication

Agile practices

Security mindset

Education

Bachelor's degree in Computer Science or related field

Tools

Go

PostgreSQL

Redis

AWS

External API integrations

Job description

What we're looking for

We are seeking a talented, endlessly curious individual to join our team. You’ll be working closely with our group of companies in the fintech sector as part of the Engineering department. This company is a leading B2B fintech platform in its field, processing over US$2B across multiple currencies annually. We’re looking for individuals who are driven to create meaningful value, take full ownership of what they build, and thrive in a fast-paced, high-growth environment. If you’re motivated by impactful work and eager to be part of an innovative team, we’d love to hear from you.

What You’ll Do

• Design, develop, and maintain scalable backend services using Go, with a strong emphasis on code quality and maintainability
• Integrate with third-party payment services (e.g. banks, e-wallets) and handle edge cases such as ambiguous or delayed responses
• Write robust unit and integration tests for all new features and ensure proper validation for critical payment flows
• Collaborate cross-functionally with product, infra, and QA teams to define, design, and ship high-impact features
• Guide and mentor junior and mid-level engineers, providing technical leadership through code reviews, design discussions and pairing sessions
• Lead by example in enforcing clean architecture, clear documentation, and reliable observability practices
• Identify and resolve performance bottlenecks, improve system resilience, and optimize for correctness and traceability
• Stay up to date with emerging technologies and propose improvements aligned with business goals
• Build software with security and compliance in mind, ensuring proper access control, logging, and auditing
• Deploy applications to AWS infrastructure and support operational readiness of services

What you should have

• Bachelor's degree in Computer Science or a relevant field
• 5+ years of backend engineering experience, with production-level experience in Go
• Proven track record of integrating with external APIs, especially in payment, banking, or financial services
• Strong foundation in system design, test-driven development, and writing maintainable, well-documented code
• Comfortable working with PostgreSQL and Redis in high-availability environment
• Experience with test automation and methodologies for both unit and integration testing
• Strong communication skills - able to explain trade-offs clearly to both technical and non-technical stakeholders
• Familiarity with Agile practices and a commitment to continuous improvement
• Security-conscious mindset; familiarity with OWASP vulnerabilities and mitigation techniques
• Demonstrated leadership in team settings - mentoring, reviewing and leveling up peers
• Excellent communication and documentation skills in English.

About Us

Xenith is a B2B payment service provider focused on enabling seamless cross-border commerce. With an MSB license in Canada and PJP III license in Indonesia, we offer global merchants a one-stop solution to manage multi-currency payments - with a strong focus on alternative payment methods in emerging markets. Our deep regional expertise and strong partnerships with top local gateways, we simplify the complexity of fragmented payment landscapes, helping global merchants expand faster and more efficiently. At Xenith, we believe in building a culture where people feel empowered, trusted, and challenged to do their best work. Join us as we build the financial infrastructure of tomorrow!