Principal Backend Engineer (Fintech)

TL;DR

Principal Backend Engineer (Go/Python/Node): Building and optimizing the backend of a global financial operating system with an accent on payment infrastructure, spend management, and AI integration. Focus on designing scalable microservices, implementing reliable LLM pipelines, and ensuring high-performance transaction processing.

Location: Remote (LATAM). Fluent in Spanish or Portuguese is required

Company

A groundbreaking financial operating system providing corporate cards, cross-border payments, and spend management software for global businesses.

What you will do

• Design and maintain scalable backend services for financial transactions across 20+ countries.
• Develop production-quality code in Go, Python, or Node.js/TypeScript and design RESTful/GraphQL APIs.
• Optimize relational and non-relational database schemas using PostgreSQL, MongoDB, and Redis.
• Integrate LLM APIs (OpenAI, Anthropic) to build features like spend categorization and document parsing.
• Implement security best practices and manage CI/CD pipelines, distributed tracing, and operational visibility.
• Collaborate with cross-regional teams using English and Spanish or Portuguese.

Requirements

• 5+ years of professional backend engineering experience building production systems.
• Professional fluency in English is required for daily global collaboration.
• Fluency in Spanish or Portuguese is required for collaboration with LATAM teammates and partners.
• Strong proficiency in at least one language: Go, Python, or Node.js/TypeScript.
• Experience with microservices, event-driven architectures, and PostgreSQL.
• Proficiency with cloud infrastructure (AWS, GCP, or Azure), Docker, and Kubernetes.

Nice to have

• Experience in fintech, payment rails, or regulated industries (KYC/AML, PCI-DSS).
• Prior experience in a high-growth startup environment.
• Knowledge of multi-currency systems and cross-border payment processing.
• Familiarity with Kafka or RabbitMQ.

Culture & Benefits

• Full-time remote work arrangement.
• Work with a Y Combinator-backed company recognized as one of the most promising startups.
• Collaborative, globally distributed engineering culture with an async design approach.
• Opportunity to bridge experimental AI work and production financial systems.