Senior Fullstack Engineer (Node/React) | Scale & Impact

Open Technology Group; Ciudad de Mendoza; On-site; ARS 1,000,000 - 2,000,000; Full time

Job summary

Open Technology Group is seeking a Full Stack Engineer to join the Cloud Platform Engineering Team in Mendoza, Argentina. You will build and scale end-to-end web applications, connecting modern UIs with robust backend services and databases, while ensuring secure authentication workflows and scalable architecture.

You will design PostgreSQL schemas for performance, build RESTful APIs, containerize applications, and implement OIDC/OAuth 2.0 with Keycloak across frontend and backend services.

Qualifications

• 3+ years of professional software development experience.
• Experience in building end-to-end web applications.
• Strong database design and query skills.
• Experience with authentication and authorization workflows.

Responsibilities

• Build and scale end-to-end web applications with frontend React and backend services.
• Design and optimize PostgreSQL schemas for performance and scalability.
• Create and consume RESTful APIs and containerize applications.
• Implement OIDC/OAuth flows using Keycloak in frontends and services.
• Secure API endpoints with JWT, token exchange and scope validation.
• Follow modern web security practices and token storage guidelines.
• Write unit, integration and contract tests; integrate tests into GitHub Actions.
• Collaborate with the engineering team to deliver reliable, scalable cloud-based apps.

Skills

React

PostgreSQL

REST APIs

Keycloak

OIDC

JWT

CORS

Containerized apps

CI/CD

GitHub Actions

Job description

The Role:

We are looking for a Full Stack Engineer to join our Cloud Platform Engineering Team.

In this role, you will be responsible for building and scaling end-to-end web applications, connecting modern and responsive user interfaces with robust backend services, database architecture, and secure authentication workflows.

Design, optimize, and query PostgreSQL database schemas with a strong focus on performance and scalability.

Build and consume RESTful APIs, packaging application logic as stateless OCI container images.

Integrate OIDC/OAuth 2.0 authorization code flows into React frontends and backend services using Keycloak.

Secure API endpoints through JWT verification, token exchange policies, and scope validation.

Implement modern web security practices, including appropriate token storage, CORS, and stateless session management.

Write and maintain unit, integration, and contract tests.

Integrate automated testing into GitHub Actions, ensuring tests are executed on every pull request.

Collaborate with the engineering team to build reliable, maintainable, and scalable cloud-based applications.

Requirements:

• 3+ years of professional software development experience, with strong hands-on experience in:


• React


• Relational databases, particularly PostgreSQL


• Experience designing and consuming REST APIs.


• Direct experience with Keycloak, including client libraries such as keycloak-js.


• Solid understanding of OIDC, OAuth 2.0, JWT, and modern web authentication and authorization practices.


• Understanding of token storage best practices, CORS, and stateless session management.


• Experience working with containerized applications and workflows.


• Experience with automated CI/CD environments, preferably GitHub Actions.


• Strong understanding of software engineering best practices and the ability to build secure, scalable, and maintainable applications.

Core Tech Stack