Backend Engineer (Offline Payment Gateway) [Bayarind]

Sprint Asia; Tangerang Selatan; On-site; IDR 82.822.000 - 115.952.000; Full time

Job summary

A fintech company in Indonesia is looking for a software developer to support backend services for terminal transactions. Candidates should possess a Bachelor's degree in a relevant field and have some experience or internships in backend development. Key responsibilities include supporting and testing communication flows and troubleshooting transaction issues. A strong interest in payment systems and willingness to learn are essential for this role.

Qualifications

• Bachelor’s degree in Computer Science, Electrical Engineering, or a related technical field.
• 0–2 years of experience in backend development.
• Strong interest in card-based payment systems and transaction protocols.

Responsibilities

• Support backend services for PG offline modules handling terminal transactions.
• Assist in building communication flows between POS terminals and host systems.
• Help debug transaction failures and contribute to internal documentation.

Skills

Backend development

Card-based payment systems

Networking (TCP/IP)

Linux command line

Teamwork and communication

Education

Bachelor’s degree in Computer Science or related

Tools

Java

PostgreSQL

MySQL

jPOS

Job description

Responsibilities

• Support the development and maintenance of backend services for PG offline modules handling terminal transactions and ISO8583 messaging.
• Assist in building and testing communication flows between POS terminals and host systems using jPOS and related tools.
• Work with senior engineers to integrate EMV and card-based transaction flows (sale, void, refund, settlement, reversal).
• Help debug transaction failures, connection timeouts, and message parsing issues during QA or UAT.
• Contribute to internal documentation, logs, and monitoring setup to support ongoing operations and certification efforts.

Requirements

• Bachelor’s degree in Computer Science, Electrical Engineering, or a related technical field.
• 0–2 years of experience in backend development (internship or project experience in fintech is a plus).
• Strong interest in card-based payment systems, terminal communication, and transaction protocols.
• Willingness to learn ISO8583 message formats, EMV standards, and jPOS architecture.
• Basic understanding of networking (TCP/IP, sockets) and API interactions.
• Familiarity with Java (or willingness to learn), especially for working with jPOS.
• Understanding of REST APIs, JSON, HTTP, and SQL databases (PostgreSQL/MySQL).
• Comfortable using Linux command line, reading logs, and basic debugging.
• Bonus: knowledge of Golang, smart card technology, or APDU command structures.
• Fast learner with attention to detail and a problem-solving mindset.
• Strong teamwork and communication skills, especially when working with QA, hardware, or frontend teams.
• Comfortable working in structured and regulated environments (e.g., fintech or banking).
• Internship or academic project experience in payment systems, POS, or embedded software is a strong plus.
• Enthusiastic about building a career in card payments, EMV, and transactional infrastructure.