Fullstack Engineer – Integrations | Fully Remote

Location: Fully Remote

Job Category: Information Technology (IT) & Software;
Finance & Accounting;
Banking & Insurance

Rezerv is hiring a Fullstack Engineer to develop and maintain payment integrations for its booking, payments, and studio management platform. The company supports more than 1,000 fitness, wellness, and sports businesses across Southeast Asia.

The role focuses on integrating third-party payment providers, including Hit Pay and Pay Pal, and maintaining reliable payment connections through REST APIs, webhooks, and other payment-related technologies. The successful candidate will work across frontend and backend systems to deliver secure, scalable, and dependable payment functionality.

This opportunity is suited to an experienced fullstack developer with expertise in React.js, Next.js, C#, and ASP.NET Core. Candidates with payment gateway integration experience will be preferred. The position also offers an opportunity to deepen technical expertise in payment systems, API integrations, transaction processing, and modern software development.

• Integrate and maintain third-party payment gateways and payment APIs.
• Develop payment-related features across frontend and backend applications.
• Implement and maintain payment flows, webhooks, transaction status updates, and refund functionality.
• Troubleshoot payment integration issues, API errors, and transaction-related problems.
• Build and maintain reliable, secure, and scalable payment integrations.
• Collaborate with product and engineering teams to develop and deliver new payment features.
• Maintain integrations with providers such as Hit Pay, Pay Pal, and other third-party services.

• At least 3 years of fullstack development experience.
• Strong experience with React.js and Next.js.
• Strong experience with C# and ASP.NET Core.
• Experience working with REST APIs and webhooks.
• Experience with third-party API integrations.
• Payment gateway integration experience is highly preferred.
• Strong troubleshooting, analytical, and problem-solving skills.

Technical environment:

• Frontend:
  React.js, Next.js
• Backend: C#, ASP.NET Core
• Integration technologies: REST APIs, webhooks, payment APIs
• Payment providers:
  Hit Pay, Pay Pal, and other third-party providers

Compensation: Salary is paid in Singapore dollars (SGD). The specific salary range has not been disclosed.

The original job description does not specify additional employee benefits, training allowances, or certification support. Candidates should confirm these details directly with the employer.

The position provides opportunities to develop professional expertise in payment integrations, API development, transaction processing, and fullstack engineering. Experience in these areas can support long-term career growth in fintech, payment technology, and software engineering.