Senior Fullstack Software Engineer

KMS provides the enterprise execution layer, where work becomes outcomes.

We are a global, AI-native technology services company focused on Enterprise Execution. We help enterprises build and modernize applications, create trusted data foundations, put AI into production, and continuously run and improve the systems that execute the work.

Founded in 2009 in the U.S., KMS has grown to serve clients worldwide, with locations across the U.S., Vietnam, Poland, and Mexico. We are trusted by technology and business leaders for the quality of our engineering, delivery, and execution. Our mission is to help enterprises move from business intent to measurable outcomes faster - with the control, reliability, governance, and confidence required to scale.

At KMS, we believe sustainable growth is built on the success of our clients and employees and on making a lasting contribution to our communities.

We are seeking a highly skilled Senior Fullstack Engineer with strong experience in React, TypeScript, JavaScript, Node.js, and NestJS to design, develop, and maintain scalable applications and services for the healthcare industry. This role focuses on building modern web applications, backend services, and system integrations while ensuring high standards of performance, security, and reliability.

The ideal candidate has a solid understanding of modern web development, enjoys building intuitive user interfaces, and is comfortable developing and integrating backend services. You will work with a modern AI-Driven technology stack that includes React, TypeScript, NodeJS, and Medplum, contributing to the development of healthcare solutions that improve clinical workflows and user experiences.

Responsibilities

• Design, develop, and maintain scalable web applications using React, TypeScript, and JavaScript.

• Design, develop, and maintain scalable backend services and RESTful APIs using Node.js and NestJS.

• Develop reusable frontend components, custom hooks, and modular application architectures following modern development best practices.

• Design, develop, and integrate RESTful APIs with internal and third-party systems.

• Implement authentication, authorization, and Role-Based Access Control (RBAC) to ensure secure access to application functionality and sensitive data.

• Develop responsive, accessible, and user-friendly interfaces based on UI/UX designs and accessibility best practices.

• Collaborate with cross-functional teams to understand business requirements, technical specifications, and healthcare-related workflows.

• Write and maintain unit and integration tests to ensure application quality, reliability, and maintainability.

• Participate in code reviews, providing constructive feedback and promoting clean coding standards.

• Troubleshoot application issues, identify root causes, and implement maintainable solutions.

• Ensure sensitive healthcare information is handled securely in application code, logs, integrations, and error-handling processes.

• Take ownership of assigned features throughout the software development lifecycle, from technical design and implementation to testing and delivery.

• Create and maintain technical documentation for application components, APIs, and integrations.

• Leverage AI-assisted development tools to improve coding efficiency, code quality, and development workflows.

• Participate in Agile ceremonies, communicate development progress, and proactively identify and escalate technical risks or blockers.

• 8+ years of professional software development experience, with strong hands-on experience in fullstack web application development.

• Advanced proficiency in React, TypeScript, JavaScript (ES6+), HTML5, and CSS3.

• Strong hands-on experience developing backend applications and RESTful APIs using Node.js, NestJS, and TypeScript.

• Experience designing and implementing Single Page Applications (SPAs), reusable components, custom hooks, and modular frontend architectures.

• Strong experience building, consuming, and integrating RESTful APIs, including asynchronous operations and error handling.

• Practical experience integrating LLM APIs, tool calling, or agentic AI workflows into software applications.

• Experience with Spec-Driven Development or AI-driven Software Development Lifecycle practices to improve development efficiency, code quality, and software delivery.

• Experience implementing authentication, authorization, and secure application development practices.

• Strong understanding of software architecture, design patterns, and clean coding principles.

• Experience with automated testing, including Jest, React Testing Library, or similar testing frameworks.

• Experience developing responsive and accessible web applications, including familiarity with WCAG accessibility guidelines.

• Experience working with Git, GitHub, CI/CD pipelines, and code review processes.

• Familiarity with AI-assisted development tools such as Claude Code, GitHub Copilot, or Cursor.

• Strong analytical, troubleshooting, and problem-solving skills.

• Ability to work independently, take ownership of technical deliverables, and adapt to changing requirements.

• Excellent written and verbal English communication skills, with experience collaborating with cross-functional and international teams.

• Experience working in Agile/Scrum development environments.

Preferred

• Experience developing applications for the healthcare industry or other regulated environments.

• Familiarity with healthcare interoperability standards such as HL7 FHIR.

• Experience with Medplum or similar healthcare platforms for managing clinical data and electronic health records.

• Understanding of healthcare data privacy and security requirements, including HIPAA and the protection of Protected Health Information (PHI).

• Experience with backend development using Python or other server-side technologies.

• Experience using Figma to implement UI designs and collaborate with design teams.

Perks you enjoy at KMS Mexico

• Mexican law benefits
• 15 days of PTO (in year zero, from the first year onwards it is 3 days per year).
• 5 days' leave for the death of immediate family members, negotiable.
• Major Medical Expenses Insurance with coverage for immediate dependents (spouse and children).
• Annual performance bonus (≈10% of annualized salary).
• Annual salary adjustment.
• Employee Referral Bonus.
• Paid Certifications / Courses
• Coursera License.
• 5% Savings Fund.
• 5% Grocery Vouchers.