Full-Stack Developer

SAIC•Silver Spring, MD

9d•Onsite

About The Position

We are seeking an experienced Full-Stack Developer to design, develop, integrate, test, modernize, and support secure, data-intensive enterprise applications. The successful candidate will work across both modern and legacy technology stacks, including React/TypeScript and JavaScript, Python, C/C++, shell scripting, REST APIs, and SQL/MariaDB. The role requires the ability to create new applications and services while maintaining, troubleshooting, integrating, and incrementally modernizing existing legacy code and systems. The position will work closely with solution architects, front-end developers, DevOps engineers, AI/ML engineers, QA personnel, and business stakeholders in an Agile/Scrum environment.

Requirements

Bachelors and nine (9) years or more experience; Masters and seven (7) years or more experience ; PhD or JD and four (4) years or more experience.
Master's degree is preferred in Computer Science, Software Engineering, Information Systems, Data Science, Artificial Intelligence, or a related technical discipline.
5+ years of professional software-development experience, including full-stack web application development.
Strong hands-on experience with React and strong proficiency in TypeScript and JavaScript.
Strong proficiency in HTML5 and CSS3.
Experience developing modern, component-based, data-intensive web applications.
Experience designing and developing RESTful APIs and server-side business logic.
Working knowledge of AI/LLM concepts and AI agent-based application patterns, including prompt-driven workflows, tool/function calling, orchestration, context handling, and human-in-the-loop controls.
Experience integrating front-end applications with backend APIs and enterprise services.
Experience working across mixed-language codebases and understanding dependencies between legacy and modern application components.
Experience maintaining and modernizing legacy applications while developing new functionality and integrations.
Proficiency with Linux shell scripting (such as Bash) for automation, troubleshooting, and operational support.
Proficiency with JavaScript/TypeScript for modern web application development.
Strong programming experience with Python for backend development, automation, integration, data processing, or application support.
Strong programming experience with C and C++, including the ability to read, debug, maintain, and enhance existing legacy codebases.
Strong working knowledge of SQL and relational database design.
Hands-on experience with MariaDB/MySQL or comparable relational database technologies.
Ability to develop and optimize SQL queries and troubleshoot database-related application issues.
Experience implementing authentication, authorization, and role-based access controls.
Experience with Git and modern source-control practices.
Experience with automated unit and integration testing.
Experience working in a Linux-based development environment and using the Linux command line/shell.
Experience using Visual Studio Code (VS Code) or a comparable modern IDE.
Understanding of secure software-development practices.
Experience debugging applications across UI, API, backend, and database layers.
Experience working within an Agile/Scrum software-development environment.
Strong analytical, troubleshooting, problem-solving, written, and verbal communication skills.
Must be a US Citizen and able to obtain and maintain a Public Trust.

Nice To Haves

Experience integrating Python, C/C++, shell-based utilities, JavaScript/TypeScript applications, and relational databases in enterprise environments.
Experience modernizing legacy applications through refactoring, API enablement, service decomposition, or incremental replacement strategies.
Experience with legacy C/C++ build systems, libraries, compilers, debugging tools, and Linux-based development workflows.
Advanced experience with React and TypeScript and modern React routing, state-management, and data-fetching approaches.
Experience developing enterprise dashboards and workflow-oriented applications.
Experience with React Testing Library, Jest, Vitest, or comparable testing technologies.
Strong experience with MariaDB/MySQL, including schema design, indexing, query optimization, and performance troubleshooting.
Experience developing and consuming APIs in a microservices or service-oriented architecture.
Experience with enterprise SSO/MFA and identity-management solutions.
Experience integrating applications with Microsoft 365 and/or SharePoint.
Experience with Section 508/WCAG accessibility requirements.
Experience developing applications incorporating AI/ML, LLM, or agentic AI capabilities and integrating AI services through APIs.
Familiarity with AI agent frameworks, agent orchestration patterns, retrieval-augmented generation (RAG), tool/function calling, structured outputs, evaluation, monitoring, and guardrails is a plus.
Familiarity with human-in-the-loop AI workflows, CI/CD, DevSecOps practices, and containerized application environments.
Familiarity with Posit (formerly RStudio) products and development environments is a plus.
Experience working with data science, analytics, AI/ML, or research teams is a plus.
Experience supporting federal government, healthcare, life-sciences, or other regulated environments is preferred.

Responsibilities

Design, develop, test, and maintain full-stack enterprise web applications.
Develop front-end functionality using React, TypeScript, JavaScript, HTML5, and CSS3.
Develop reusable, modular, responsive, and accessible React components.
Develop server-side APIs, application services, and business logic.
Design and implement RESTful APIs supporting front-end and system integrations.
Implement server-side validation, error handling, logging, and application security controls.
Implement authentication, authorization, and role-based access control (RBAC), including support for enterprise SSO/MFA.
Develop and maintain application functionality using SQL and MariaDB/MySQL.
Design and work with relational database tables, relationships, queries, views, indexes, and data structures.
Develop and optimize SQL queries supporting application functionality, reporting, testing, and troubleshooting.
Support database schema changes, data migration, validation, and troubleshooting.
Develop dashboards, forms, workflow interfaces, search/filter functionality, reporting, and detailed record views.
Integrate applications with enterprise document-management and other internal services, including Microsoft 365 and/or SharePoint where applicable.
Develop interfaces and backend services supporting AI/ML, large language model (LLM), and AI agent capabilities, including human-in-the-loop review and approval workflows.
Integrate AI/LLM and agent-based services through APIs and approved application interfaces, including tool/function calling, workflow orchestration, structured outputs, and application guardrails.
Implement application logging, exception handling, auditing, and operational diagnostics.
Write unit, integration, and automated application tests and participate in peer code reviews.
Troubleshoot and optimize issues across the front end, backend, APIs, database, and integration layers.
Support System Integration Testing (SIT), User Acceptance Testing (UAT), regression testing, and production deployment.
Collaborate with DevOps engineers on CI/CD, build, deployment, configuration, and release processes.
Integrate legacy C/C++, Python, shell, JavaScript, database, and modern web components through well-defined APIs and interfaces.
Refactor and modernize legacy code incrementally while preserving required behavior, compatibility, security, and operational continuity.
Analyze and understand existing legacy source code, interfaces, dependencies, build processes, and data flows before implementing changes.
Develop and maintain shell scripts for Linux-based automation, application support, data processing, deployment, and operational tasks.
Develop backend services, automation, data-processing utilities, and integration components using Python.
Develop, maintain, troubleshoot, and enhance software written in C and C++, including existing legacy components and interfaces.
Develop and troubleshoot applications in a Linux-based working environment.
Use Visual Studio Code (VS Code) for application development, debugging, Git workflows, and related engineering activities.
Create and maintain application and technical documentation.
Participate actively in Agile/Scrum ceremonies, including sprint planning, daily stand-ups, backlog refinement, estimation, sprint reviews/demonstrations, and retrospectives.
Support iterative software releases and respond to feedback identified during testing and stakeholder reviews.