Full Stack MERN Developer

Location: São Paulo, São Paulo, Brazil, Santiago, Santiago Metropolitan Region, Chile, Medellín, Medellin, Colombia, Montevideo Department, Uruguay, Buenos Aires, Buenos Aires, Argentina, Lima, Callao Region, Peru

Department: Workana Premium

Workplace: remote

Description

Workana is the largest remote work platform for talents in Latin America. Our Workana Premium segment focuses on connecting exceptional professionals with leading companies around the world, offering competitive compensation, dedicated support, and the flexibility of remote work.

We are pleased to present the following opportunity.

About Our Client

OurOffice is a U.S.-based SaaS startup developing technology solutions for organizations that need secure, scalable, and reliable software. The company is seeking a senior-level Full Stack MERN Developer to work directly with its hands-on CTO and take ownership of complex production systems.

The ideal candidate will be comfortable working across the frontend, backend, database, integrations, and AWS infrastructure. A key initiative for this role is the development of a secure Data Export and Analytics API that will allow external platforms, including Microsoft Power BI, to access organization-scoped SaaS data efficiently and securely.

Role Overview

As a Full Stack MERN Developer, you will maintain and scale an established MERN application while building new features and improving the platform’s security, performance, reliability, and observability.

You will be responsible for designing and implementing secure multi-tenant APIs, large-data processing workflows, integrations with third-party services, and end-to-end product features using React, Redux, Node.js, Express, MongoDB, and AWS.

This is a long-term remote opportunity for a senior or expert engineer based in Latin America who can work during U.S. West Coast business hours and communicate fluently in English.

Responsibilities

• Maintain, debug, and scale a production MERN application.
• Build secure Data Export and Analytics APIs for Microsoft Power BI and other external systems.
• Design large-data workflows using MongoDB cursors, batching, Node.js streams, CSV exports, and Amazon S3.
• Implement secure multi-tenant access with authentication, authorization, API credentials, rate limiting, and strict organization-level data isolation.
• Design and optimize MongoDB and Mongoose schemas, indexes, aggregation pipelines, Atlas Search configurations, and database queries.
• Analyze query performance using tools such as explain() and implement appropriate optimization strategies.
• Build reliable asynchronous workflows with concurrency controls, retries, idempotency, leases, locks, timeouts, and failure recovery.
• Develop new features end-to-end across React, Redux, Node.js, and Express.
• Integrate and maintain third-party services, including AI/NLP tools, Twilio, SendGrid, Stripe, Microsoft services, Slack, and AWS services.
• Improve application performance, security, reliability, logging, monitoring, and observability.
• Investigate and resolve production issues in a large, established application.
• Collaborate directly with the CTO to define technical solutions, prioritize work, and deliver reliable production features.
• Contribute to technical documentation, development standards, and continuous improvement of the platform.

Requirements

• 5+ years of professional experience developing full stack applications with the MERN stack.
• Advanced experience with MongoDB, Express, React, and Node.js.
• Strong experience designing and developing backend systems and production-grade APIs.
• Proven experience building data-access, reporting, analytics, or data-export APIs.
• Strong knowledge of REST APIs, API design, and API versioning.
• Solid understanding of authentication, authorization, and multi-tenant application security.
• Practical experience with Node.js streams, backpressure, batching, and processing large datasets without loading everything into memory.
• Strong knowledge of concurrency, retries, idempotency, timeouts, failure recovery, and asynchronous processing.
• Deep experience with MongoDB indexes, aggregation pipelines, query optimization, explain(), and Mongoose.
• Strong AWS experience, particularly with EC2, S3, IAM, CloudFront, and WAF.
• Strong React and Redux experience in established production codebases.
• Availability to work in alignment with U.S. West Coast / Los Angeles business hours.

Nice to Have

• Experience integrating applications with Microsoft Power BI or Power Query.
• Knowledge of Tableau, Looker, OData, or other analytics and data-platform integrations.
• Experience with Amazon SQS, EventBridge, Lambda, or background-worker architectures.
• Experience integrating Twilio, SendGrid, Stripe, Microsoft Graph, Azure, Okta, SAML, or Slack.
• Experience with AI/LLM integrations, embeddings, vector search, or retrieval-augmented generation systems.
• Experience with CI/CD, automated testing, deployment pipelines, and production releases.
• Previous experience working in SaaS, B2B software, or multi-tenant environments.

Benefits

• Compensation in USD.
• Fully remote, long-term opportunity.
• Work directly with a technical founder and CTO.
• Professional growth toward a technical lead position.