Golang Engineer (Card Payments)

Castle Island; Singapore; Hybrid; SGD 90,000 - 150,000; Full time

Job summary

BIT is looking for a skilled Golang backend engineer to support its card payment and card issuing systems in Singapore. You will develop and optimize core services handling issuance, accounts, authorization, clearing, settlement, and billing.

You will contribute to end-to-end transaction flows, system architecture, and performance improvements while ensuring security and reliability in a high‑volume fintech environment. Collaboration with product, security, and operations is expected.

Qualifications

• Bachelor's degree or higher in Computer Science or related field.
• 3+ years of experience in Golang and/or Java development.
• Hands-on experience in card issuing/payments/system processing is preferred.
• Strong understanding of concurrent programming and Linux proficiency.
• Familiarity with Docker, Kubernetes, gRPC, Protobuf, and CI/CD.

Responsibilities

• Develop Golang backend for card payment and issuing systems, including issuance, accounts, authorization, settlement, and billing modules.
• Design and implement end-to-end card transaction lifecycle (Authorization, Reversal, Capture, Refund, Reconciliation).
• Contribute to system architecture design, migration of legacy systems, and performance optimization.
• Improve throughput and reliability under high concurrency while ensuring data security and accuracy.
• Maintain technical documentation, enforce code quality, conduct reviews, and write tests.

Skills

Golang

Java

Linux

Data structures

Concurrent programming

Education

Bachelor's degree in Computer Science

Tools

Docker

Kubernetes

gRPC

Protobuf

CI/CD

Job description

About BIT:

BIT (formerly Matrixport) is a global digital asset financial services and infrastructure group. Headquartered in Singapore and founded in 2019, BIT bridges traditional finance and digital assets through governance-driven financial services and technology.

The firm manages over US$7 billion in assets and facilitates more than US$7 billion in monthly trading volume. BIT offers services including custody, trading, asset and wealth management, liquidity and financing solutions, and tokenised real-world assets (RWA), serving institutional and professional investors globally.

BIT Group entities maintain a licensed and regulated footprint across Singapore, Hong Kong, Switzerland, the United Kingdom, the United States and Bhutan.

For more information, visit www.bit.com

Why Join Us:

At BIT, we tackle complex problems as a team. We encourage openness and promote transparency, respect, and inclusivity. Every team member is valued and has a voice that can be heard. We are always in search of intellectually curious and entrepreneurial individuals who are keen on making an impact in the crypto ecosystem and in building a better product for the next one billion users.

Job Responsibilities:

• Core Business Development: Responsible for Golang backend development of the company's card payment and card issuing systems, including but not limited to card issuance, card accounts, authorization, clearing & settlement, transaction processing, billing, rewards/benefits, and other related business modules.
• Card Transaction Lifecycle: Participate in the design and development of the end-to-end card transaction lifecycle, with a solid understanding of and hands‑on experience with core transaction flows such as Authorization, Reversal, Capture, Refund, and Reconciliation.
• Architecture Design & Optimization: Participate in system architecture design, legacy system analysis and migration, continuous iteration and performance optimization, ensuring high availability, strong consistency, and stability of financial systems.
• Technical Problem Solving: Identify and resolve technical challenges and system bottlenecks, improve system throughput and response time, and ensure fund security and data accuracy under high‑concurrency transaction scenarios.
• Engineering Quality: Maintain high-quality technical documentation, enforce code quality standards, conduct Code Reviews, and develop unit and integration test cases.

Job Requirements:

• Bachelor's degree or above in Computer Science or a related field, with 3+ years of experience in Golang and/or Java development.
• Hands‑on experience in card issuing systems, card payment systems, or card transaction processing systems; directly relevant experience is highly preferred.
• Basic understanding of crypto fundamentals and how crypto systems operate; experience in crypto trading or payments is a plus.
• Strong proficiency in Golang and/or Java, with a solid understanding of concurrent programming. Proficient in Linux and possessing a strong foundation in data structures. Familiarity with Kubernetes (K8s), computer networking, and related technologies.
• Strong proficiency in MySQL, with the ability to perform SQL performance tuning. Proficient in Redis and other caching technologies, with a good understanding of common solutions for cache breakdown, cache penetration, and cache avalanche.
• Familiar with microservices architecture and proficient in gRPC and Protobuf. Understanding of microservice governance, including service registration and discovery, circuit breaking, rate limiting, and distributed tracing.
• Familiar with containerization technologies such as Docker and Kubernetes, as well as CI/CD processes.
• Proficient in tools such as Claude Code and Codex, with the ability to integrate AI into daily development workflows to improve efficiency and create valuable, reusable workflows.

Preferred:

• Experience in risk control/fraud prevention for Crypto Card or payment applications is preferred.
• Experience developing systems for licensed card issuers, acquiring institutions, third‑party payment providers, or Card Processors.
• Familiarity with ISO 8583 / ISO 20022 messaging, or experience integrating with card networks or card‑issuing partners.
• Experience with crypto deposits/withdrawals, Crypto Cards, or fiat on/off‑ramp products and business processes.
• Familiarity with PCI‑DSS and other payment compliance and security standards.
• Experience building payment systems from 0 to 1 or migrating core payment systems.

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