Senior Full Stack Developer

About DMI DMI is a leading provider of digital services and technology solutions, headquartered in Tysons Corner, VA. With a focus on end-to-end managed IT services, including managed mobility, cloud, cybersecurity, network operations, and application development, DMI supports public sector agencies and commercial enterprises around the globe. Recognized as a Top Workplace, DMI is committed to delivering secure, efficient, and cost-effective solutions that drive measurable results. Learn more at www.dminc.com About the Opportunity DMI is seeking a Senior Full-Stack Developer to help build and modernize a mission-critical Department of Defense enterprise application. The system is an offline-first Progressive Web Application (PWA) that operates seamlessly across connected command centers, intermittent tactical networks, and fully disconnected environments. The role spans the full stack: a React and TypeScript front end, a Node and Express back end migrating to AWS serverless, and the synchronization and integration layers that keep the product working when the network does not. This is an AI-first engineering team. We deliver using an AI-augmented development methodology built around agentic coding tools, and fluency with those tools is a core competency of this role. Senior developers spend a meaningful share of each week directing, reviewing, and hardening AI-generated code, and they remain fully accountable for every line that ships. Duties and Responsibilities:  Perform detailed design, development, unit and integration testing, and delivery of features spanning the front end, back end, synchronization layer, and external integrations. Produce scalable, secure, high-quality TypeScript and Node code that satisfies both functional and non-functional requirements (performance, offline resilience, accessibility, security). Build and maintain an offline-first PWA front end in React and TypeScript, using Redux Toolkit for state, Material UI for theming, and Vite for builds; implement service workers, background sync, and encrypted at-rest storage (IndexedDB with FIPS-validated AES-256-GCM). Build and maintain back-end services in Express and Node using established controller and repository patterns, and contribute to the incremental migration of the monolith into domain-aligned AWS Lambda services. Implement and migrate persistence across both MongoDB and DynamoDB, including modeling DynamoDB access patterns for single-table designs. Develop configurable software services that integrate the application with external DoD and enterprise systems, handling data transformation, format conversion, and delta/change-data-capture synchronization while preserving data integrity for accountability workflows. Implement multi-protocol integration (REST, SOAP, SFTP) with pluggable authentication (CAC/mTLS, OIDC, JWT, OAuth2, API key, SSH key). Design data movement and process flows for connectivity-aware operation across online, intermittent, and disconnected modes. Apply secure-development best practices and program design patterns, including layered authentication, role-based authorization, resource-level access control, and tamper-evident audit trails. Use agentic AI coding tools to generate, refactor, and migrate code in logical, reviewable chunks, then direct, review, and harden that output to program quality and security standards. Write and maintain automated tests (Jest, Vitest, Playwright, supertest, Lighthouse), participate in code reviews, and support functional, regression, performance, and accessibility testing (Section 508 / WCAG). Create and maintain design and systems documentation, architecture decision records, API specifications (OpenAPI/Swagger), and process and data-flow diagrams. Lead feature-area design, set and enforce coding standards, mentor mid-level developers, and own technical trade-off decisions for an assigned domain. Collaborate with the technical delivery lead, solutions architect, DevSecOps engineers, UX designers, cybersecurity staff, and mission users within an Agile/Scrum cadence and a Git-based CI/CD pipeline. Ensure assigned work lands within sprint and program schedules. Qualifications Education and Years of Experience:   10 or more years of overall software development experience. Five or more years of professional experience in Node, TypeScript, and React. Three or more years of building on AWS serverless. Bachelor's degree in Computer Science, Software Engineering, or a related field. Master's preferred. Equivalency: a Master's degree substitutes for two years of experience, and an Associate's degree plus four years substitutes for a Bachelor's. Security clearance and citizenship are non-waivable and carry no equivalency. Required Skills and Technologies:  Languages and runtime:  TypeScript, modern JavaScript (ES2022+), Node.js 24 Front end:  React (hooks, function components), Redux Toolkit, Material UI, and Vite; Progressive Web App development including service workers, Workbox, IndexedDB, background sync, and offline-first architecture; accessibility to Section 508 / WCAG Back end and data:  Express REST APIs using controller and repository patterns; MongoDB (Mongoose) and DynamoDB (single-table design and access-pattern modeling), with experience migrating from document or relational stores to DynamoDB strongly desired; API design with OpenAPI/Swagger Cloud and serverless:  AWS Lambda, DynamoDB, API Gateway, Step Functions, EventBridge, and SQS; a managed-service-first approach that favors AWS managed services over bespoke plumbing where they fit; incremental monolith-to-serverless (Strangler Fig) migration patterns; AWS GovCloud exposure (IL5/IL6) desired Integration and synchronization:  multi-protocol integration across REST, SOAP, and SFTP; authentication schemes including CAC/mTLS, OIDC, JWT, OAuth2, API keys, and SSH keys; delta/CDC synchronization, ETL and data transformation, an