Senior Full Stack Software Engineer

Senior Full Stack Software Engineer

Location: Hong Kong

Job Highlights

• Full stack: React (web) + Node.js/PostgreSQL + AWS CDK + payments

• 5+ years engineering experience with fintech or financial systems

• We're looking for someone who can start within the next 1 month.

About Us
We are a Hong Kong-based fintech company building mission-critical financial infrastructure across payments. This is an opportunity to work on core platform systems that handle real-time transactions and serve institutional clients. We value engineers who take ownership, ship with urgency, and care deeply about building secure, reliable financial systems.

Responsibilities

• Develop and maintain full stack features across web and backend services (Node.js, PostgreSQL) powering the company's fintech platform

• Integrate fiat banking rails and payment infrastructure including ACH, card issuing, ledger systems, and real-time payment networks (e.g., FPS, SWIFT)

• Implement authentication and security solutions including passkeys, device biometrics, OAuth, WebAuthn, and session management to protect client assets and data

• Design and consume REST APIs; build robust, well-documented service interfaces for internal and external consumption

• Participate in architecture decisions shaping system scalability, security, fault tolerance, and user trust across the platform

• Define and deploy cloud infrastructure using AWS CDK, applying infrastructure-as-code practices for reproducible, auditable, and version-controlled deployments

• Champion engineering best practices including code reviews, automated testing, CI/CD pipelines, observability, and comprehensive documentation

• Mentor junior and mid-level engineers; contribute to technical hiring and building the engineering team culture

Requirements

• Bachelor's or Master's degree in Computer Science, Software Engineering, or a related field, or equivalent professional work experience

• Minimum 5 years of professional full stack engineering experience, with demonstrated work on financial or fintech systems

• Strong proficiency in TypeScript, Node.js, and React; experience with PostgreSQL or equivalent relational databases

• Experience designing and consuming REST APIs in production environments

• Hands-on experience with AWS and infrastructure-as-code tooling

• Solid understanding of authentication models (OAuth, WebAuthn, session security) and security best practices for financial applications

• Proven ability to work effectively with AI coding agents and to critically review the code and changes they produce

• Self-starter with strong ownership mentality who thrives in ambiguous, fast-paced environments; comfortable proposing solutions and driving them to completion

• Fluent in English

Preferences
The following are not required, but candidates with any of these will stand out:

• Familiarity with AWS CDK specifically

• Experience with fintech or payments APIs (e.g., Stripe, Plaid, Marqeta, Column, Lithic, Unit) or banking integration (ACH, card networks, ledger systems)

• Fluency in native iOS (Swift) and/or native Android (Kotlin) development

• Proficiency in Cantonese and/or Mandarin

Hiring Process
Candidates progress through the following stages and must pass each one to advance to the next:

• Programming screening — an unproctored multiple-choice test covering core programming fundamentals

• Technical interviews — two live interviews (no coding) of similar content, each conducted by a different interviewer, building on the candidate's screening answers and covering software engineering fundamentals and problem-solving