Senior Backend Developer (Fintech)

Location: Buenos Aires, Argentina; hybrid with at least one office day per week

Company

Builds simple financial products and a fintech platform for users across Latin America and beyond.

What you will do

• Write maintainable TypeScript code, conduct code reviews, refactor code, and implement testing frameworks.
• Build scalable and secure RESTful APIs for communication between frontend and backend systems.
• Design secure architectures with encryption, authentication, and authorization to protect user data.
• Design, manage, and optimize PostgreSQL and MongoDB schemas, queries, and indexes for high-load performance.
• Integrate payment processing, identity verification, analytics, and other third-party financial services.
• Monitor and optimize server performance using caching, load balancing, microservices, CI/CD, and deployment improvements.

Requirements

• Strong experience with TypeScript, Git, PostgreSQL, MongoDB, RESTful APIs, and Jest.
• English proficiency is required.
• Experience designing secure, scalable backend systems and handling high-volume transactions.
• Ability to collaborate with frontend developers and DevOps on data flows, deployment, and scalability.

Nice to have

• React, Docker, AWS, shell scripting, or NestJS.
• Experience with crypto and Portuguese proficiency.

Culture & Benefits

• Opportunity to build and own the security foundation of a fast-growing fintech platform.
• Passionate environment focused on innovation, transparency, and impact.
• Competitive compensation paid in USDT.
• Six weeks of vacation and flexible working hours.
• MacBook and an annual professional development budget.
• Startup culture with flexibility, autonomy, and a results-oriented approach.