Senior Applications Developer (MERN Stack)

About the role

Oliver Wyman is looking for a Senior Applications Developer in Mexico City to design, develop and deliver modern enterprise applications that simplify business processes and improve user experience. The role combines full-stack development with the MERN stack, workflow engineering, API and system integration, cloud technologies and emerging agentic AI capabilities. The developer owns solutions across the application lifecycle, from architecture and UX through business logic, workflows, integrations, data, deployment, monitoring and continuous improvement.

Key responsibilities

• Lead the design and development of enterprise applications from concept through production, covering business, analytics, automation and data-driven use cases.
• Build full-stack applications with MongoDB, Express.js, React, Node.js, JavaScript and TypeScript, and create responsive, accessible, high-performance user experiences.
• Design application architecture spanning UI, business logic, workflows, APIs, integrations, data services, cloud components and AI-enabled capabilities.
• Implement workflows that coordinate users, business rules, approvals, APIs, data, automated processes and external systems.
• Build secure, documented REST APIs, microservices, webhooks and integration services, and design for performance, scalability, reliability and maintainability.
• Work with SQL and NoSQL databases, and develop event-driven, asynchronous capabilities with queues, messaging and background processing.
• Evaluate opportunities to incorporate generative AI, intelligent agents and agentic workflows, and choose the right technical approach for each business problem.
• Troubleshoot production issues, contribute to architecture, set development standards, review code and mentor developers.
• Partner with product owners, analysts, designers, business and data teams, and ensure compliance with security, privacy, testing, documentation and governance requirements.

Required profile

• Bachelor's degree in Computer Science, Software Engineering, Information Systems or a related field, or equivalent professional experience.
• 5+ years of software engineering or application development experience, including end-to-end production applications.
• Strong experience building full-stack applications with the MERN stack, and designing business workflows and automation solutions.
• Ability to translate complex business requirements into scalable, secure and maintainable applications, and to collaborate with technical and non-technical stakeholders globally.
• Professional English proficiency.

Required skills

• MERN stack: MongoDB, Express.js, React, Node.js, JavaScript and TypeScript.
• REST APIs, API-first architecture, JSON, webhooks, authentication and enterprise integrations.
• SQL and NoSQL databases, data modeling and query design.
• Git, automated testing, CI/CD pipelines, Agile, Docker and Kubernetes or similar.
• Preferred: Python and FastAPI, and experience with AI agents interacting with enterprise systems.