Senior Full-stack Engineer; Node.js​/React

Position: Senior Full-stack Engineer (Node.js / React)
Job Title :
Senior Full-stack Engineer (Node.js / React)
Team :
Assets (Crypto & Fiat Management)
Location :
Onsite - Ticino, Switzerland

About Us
We are a new, well-funded R&D company with a clear vision: to build the future of cryptocurrency infrastructure. Our ambition is to become the #1 cryptocurrency platform in the EU by market share within the next three years.
We are starting with a proven, operational crypto platform and are now assembling a world-class team to evolve it to the next level. Our core products include:
Golden Ratio Exchange:  An advanced, security-first exchange for professional traders.
GRX Pay:  A seamless payment gateway that allows merchants to accept crypto and receive fiat.

This is a rare opportunity to join a fresh company culture from day one, while working on the exciting technical challenges of a mature product. We are building our foundational R&D hub in  Ticino, Switzerland , and are looking for core team members to build this new culture with us.

The Role
We are looking for a Senior Full-stack Engineer to be the core technical pillar of our new  Assets team . This is a hands-on technical leadership role  without  people management responsibilities. This is one of the most critical and complex roles in our company, responsible for the entire lifecycle of customer funds.
In our structure, the "Manager" defines the  why  and  what  (product) and manages the  who  (people). As the "Senior Engineer," you are the undisputed technical expert responsible for the deep  how . You will own the architecture and execution of all systems that manage crypto and fiat assets.
Your mission is to architect, build, and maintain the microservices for blockchain infrastructure, fiat payment processing, and user fund management. You will work across the entire stack (Node.js, React, Postgre

SQL) to build highly secure, reliable, and compliant systems. You will also be responsible for re-architecting our legacy asset management systems and migrating them to a modern, service-oriented architecture.
This is a full-time, onsite role at our new R&D hub in Ticino, Switzerland.  Given the high-security nature of the Assets team, we believe co-location is essential for building a robust, trust-based engineering culture.

What You'll Do
Architect and Build:  Design, build, and maintain the new "Assets" microservices using Node.js (Nest.js) and Postgre

SQL. These services are responsible for:
Blockchain

Infrastructure:  Transaction broadcasting, fund consolidation, and wallet management.
Fiat

Infrastructure:  Integrating with banks and payment providers for fiat transaction processing.
Core Asset Functions:  The complete functionality for user deposits, withdrawals, and internal transfers to other GRX users.
Fee Systems:  The foundational functionality for GRX fees.
Full-Stack Development:  Build the user-facing front-end components (in React) for the "Assets page," "Dashboard page," and "Statement reports" for tax purposes.
Legacy Migration:  Analyze the existing legacy codebase for asset and wallet management. Design and execute a clear migration strategy to the new architecture with zero downtime.
Technical Leadership:  Act as the primary technical mentor for other engineers on the team, performing in-depth code reviews and solving the most complex architectural challenges.
Security & Compliance:  Work closely with the Manager to ensure all systems are fully compliant with MiCA, "Travel Rule" regulations, and principles of asset safeguarding and segregation.
Maintain Legacy Systems:  Analyze and maintain existing systems, such as "GRX Codes," while evaluating their compliance and long-term utility.

What We're Looking For

Experience:

5+ years of professional experience in full-stack development.
Domain Expertise:
Direct experience in Fin Tech, banking, or cryptocurrency is a hard requirement for this role.  You must have experience building systems that move or manage money.
Back-end Expertise:  Expert-level knowledge of  Type Script  and  Node.js .
Front-end Proficiency:  Strong proficiency in  React.js  and modern front-end practices.
Database

Skills:

Deep experience with relational databases ( Postgre

SQL ).
Blockchain Knowledge:  A strong, practical understanding of blockchain principles, wallets (hot/cold), and transaction life cycles.
Legacy Systems

Experience:

Demonstrable experience working with and refactoring large, existing codebases.
Architectural

Skills:

Strong understanding of microservices architecture, secure API design, and event-driven patterns.

Location:

Willingness to work  onsite in Ticino, Switzerland .
Mentorship:  A passion for mentoring other engineers and raising the technical bar for the entire team.

Bonus Points
Direct experience running or interacting with blockchain nodes (e.g., Bitcoin, Ethereum).

Experience with fiat payment processor integrations (e.g., Stripe, Braintree, or bank APIs).

Experience with message brokers ( Rabbit

MQ ) and  Redis .

What We Offer
High-Impact Role:  A unique opportunity to be the founding…