Full-Stack API Developer – Merchant Integration

Hyphenconnect

China (APAC) Remote permanent

Posted: August 31, 2025

Job Description

Job Summary

We are hiring for an innovative crypto wallet and payment network startup who are looking for a Full-Stack API Developer to build and maintain merchant integration APIs, client portals, and SDKs for our crypto wallet app’s merchant payment system. You will develop backend services to support crypto-only payments via QR/NFC and POS, contributing to the January 2026 rollout. This remote role requires expertise in API development, merchant systems, and blockchain technology.

Responsibilities

• Design and develop merchant-facing APIs and SDKs to enable crypto payments via wallet app.

• Build and maintain merchant, admin, and customer portals for transaction management and reporting.

• Integrate backend services with smart contract-based payment systems for secure transactions.

• Collaborate with the Tech Lead and Integration Engineer to align APIs with merchant requirements.

• Ensure scalability, security, and performance of APIs for online and physical POS environments.

• Document APIs and SDKs for external developers and internal teams.

Qualifications

• 5+ years of experience in full-stack development, with a focus on API and SDK development.

• Proven experience building merchant or client portals for payment systems (e.g., fintech, e-commerce).

• Strong proficiency in backend technologies (e.g., Node.js, Python, Go) and frontend frameworks (e.g., React, Vue.js).

• Familiarity with blockchain technology and crypto wallets (e.g., Solidity, Web3.js, Ethers.js).

• Experience with RESTful APIs and integration with payment gateways or POS systems.

• Ability to work remotely and align with Hong Kong/Singapore time zones.

• Bachelor’s degree in Computer Science, Engineering, or a related field (or equivalent experience).

Preferred Skills

• Experience with crypto payment gateways (e.g., Coinbase Commerce, BVNK) and QR/NFC systems.

• Knowledge of smart contract development and security (e.g., Hardhat, Foundry).

• Familiarity with POS hardware integration for in-store payments.

• Strong documentation skills for developer-facing APIs and SDKs.

Why Apply Through MisuJob?

AI-Powered Job Matching: MisuJob uses advanced artificial intelligence to analyze your skills, experience, and career goals. Our matching algorithm compares your profile against thousands of job requirements to find positions where you have the highest chance of success. This saves you hours of manual job searching and ensures you only see relevant opportunities.

One-Click Applications: Once you create your profile, applying to jobs is effortless. Your resume and cover letter are automatically tailored to highlight the most relevant experience for each position. You can apply to multiple jobs in minutes, not hours.

Career Intelligence: Beyond job matching, MisuJob provides valuable career insights. See how your skills compare to market demands, identify skill gaps to address, and understand salary benchmarks for your experience level. Make data-driven decisions about your career path.

Frequently Asked Questions

How do I apply for this position?

Click the "Register to Apply" button above to create a free MisuJob account. Once registered, you can apply with one click and track your application status in your dashboard.

Is MisuJob free for job seekers?

Yes, MisuJob is completely free for job seekers. Create your profile, get matched with jobs, and apply without any cost. We help you find your dream job without any hidden fees.

How does AI matching work?

Our AI analyzes your resume, skills, and experience to understand your professional profile. It then compares this against job requirements using natural language processing to calculate a match percentage. Higher matches mean better fit for the role.

Can I apply to jobs in other countries?

Absolutely. MisuJob features jobs from companies worldwide, including remote positions. Filter by location or look for remote opportunities to find jobs that match your preferences.

Ready to Apply?

Join thousands of job seekers using MisuJob's AI to find and apply to their dream jobs automatically.