Senior Full Stack MERN Developer (Remote)

About Our Client:

OurOffice is a U.S.-based SaaS startup developing secure, scalable, and reliable software for organizations. They are seeking a senior-level Full Stack MERN Developer to work directly with their hands-on CTO and take ownership of complex production systems.

The ideal candidate will work across frontend, backend, database, integrations, and AWS infrastructure. A key initiative is the development of a secure Data Export and Analytics API for external platforms like Microsoft Power BI.

Role Overview:

As a Full Stack MERN Developer, you will:

• 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 like explain() and implement 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.