Sr. Backend Developer

Aliancers; Rosario; On-site; ARS 1,200,000 - 1,800,000; Full time

Job summary

Aliancers is seeking a Sr. Backend Engineer in Argentina to architect and develop scalable backend services using NestJS, focusing on PostgreSQL optimization and robust data models for financial workflows.

You will design RESTful APIs, lead system design decisions, and mentor junior engineers while leveraging AWS services and modern testing practices. Fluency in English and Spanish is required for cross-team collaboration.

Qualifications

• 7+ years of professional JavaScript development experience.
• 7+ years of professional Node.js development experience.
• Extensive experience with NestJS framework.
• 6+ years of professional PostgreSQL experience and relational DB design.
• Fluency in English & Spanish (Must).
• Proven track record of designing scalable, high-performance backend systems.

Responsibilities

• Architect and develop high-performance backend services using NestJS for scalability and maintainability.
• Design and optimize PostgreSQL schemas and query performance.
• Implement complex business logic and integration patterns for financial workflows.
• Create and maintain RESTful APIs with performance focus.
• Develop robust data modeling strategies for financial configurations.
• Lead backend system design and technical decision-making.
• Mentor junior engineers and contribute to team culture.
• Establish backend observability and monitoring infrastructure.
• Collaborate with frontend, product, and design teams for seamless integration.

Skills

JavaScript

Node.js

NestJS

PostgreSQL

TypeScript

REST APIs

AWS

Testing

Microservices

Observability

English

Spanish

Docker

CI/CD

RabbitMQ

Kafka

Tools

Docker

Terraform

Kubernetes

CloudFormation

RabbitMQ

Kafka

AWS CloudFormation

Job description

As a Sr. Backend Engineer you will:

• Architect and develop high-performance backend services using NestJS, ensuring scalability and maintainability
• Design and optimize PostgreSQL database schemas and query performance
• Implement complex business logic and integration patterns for financial service workflows
• Create and maintain RESTful APIs with exceptional performance characteristics
• Develop robust data modeling strategies that support complex financial service configurations
• Lead backend system design and technical decision-making
• Leverage AWS cloud services to build scalable and reliable infrastructure
• Mentor junior engineers and contribute to the overall engineering team culture
• Implement comprehensive testing strategies, including unit and integration testing
• Establish and maintain backend observability and monitoring infrastructure
• Collaborate closely with frontend, product, and design teams to ensure seamless system integration

You'll be a great fit if you have:

• 7+ years of professional JavaScript development experience
• 7+ years of professional Node.js development experience
• Extensive experience with NestJS framework
• 6+ years of professional experience with PostgreSQL and relational database design
• Fluency in English & Spanish (Must). The team primarily communicates in Spanish, so strong written and verbal Spanish skills are essential.
• Proven track record of designing scalable, high-performance backend systems
• Deep understanding of TypeScript and advanced JavaScript patterns
• Strong experience with RESTful API design and implementation
• Expertise in database optimization and performance tuning
• Comprehensive knowledge of backend testing methodologies
• Substantial AWS cloud services experience, including: Amazon EC2 Amazon RDS AWS Lambda Amazon S3 AWS CloudWatch Infrastructure as Code (CloudFormation or Terraform)
• Experience with microservices architecture
• Strong debugging and systems troubleshooting skills

Bonus points if you have:

• Knowledge of the financial services domain
• CI/CD pipeline configuration experience
• Docker experience
• Message queue systems (RabbitMQ, Kafka) experience
• Backend observability tools experience

Need only Argentina candidates who speak both fluent English and Spanish