Senior Full Stack Engineer

Job Description

ECS is seeking a highly skilled Senior Full Stack Engineer with extensive experience in designing, building and maintaining large scale API’s for enterprise level applications to work remote and/or in our Washington DC area office in support of the Department of Homeland Security.

This role will focus heavily on modernizing legacy systems with deprecated code bases, requiring both technical expertise and creative problem‑solving abilities. You will play a critical role in rearchitecting our application’s API infrastructure, ensuring scalability, reliability and long‑term maintainability. Tools necessary for excelling in this role include Java (with Maven, Gradle, etc), JavaScript Frontend frameworks (React, Angular, etc), Elastic and other data sources, and Dev Sec Ops  in the Cloud.

Key Responsibilities:

• Support the design and architecture of robust, scalable API’s for large enterprise level applications.
• Integrate and operate CI/CD pipelines used for building and releasing code and container images.
• Assess and refactor deprecated code bases implementing best practices for modernization and performance improvement.
• Collaborate with engineers to integrate React‑based user interfaces with scalable APIs, leveraging React expertise to enhance API interactions, support legacy system modernization, and ensure seamless functionality and optimal user experience.
• Provide solutions for legacy system migration while minimizing system downtime and operational risks.
• Identify and resolve technical debt in older systems while transitioning them to modern Java frameworks and tools.

Salary Range: $145,000 – $175,000

General Description of Benefits

Required Skills

• Bachelor’s degree in a relevant field
• Be a
• Ability to pass a Public Trust background investigation
• 8+ years with Java (8 and beyond) with strong experience in legacy system modernization.
• 5+ years developing responsive web apps using React, Redux, and modern JavaScript.
• Strong background in API development, including 5+ years building RESTful microservices and service‑oriented architectures.
• 3+ years of experience with CI/CD pipelines and deploying/operating in AWS or Azure Cloud environments.
• 3+ years of experience with Springboot or other stateless Java frameworks
• 3+ years developing applications in a production setting and troubleshooting complex issues within legacy environments and proposing effective solutions.
• Solid understanding of Git, version control workflows, and collaborative development practices.
• Familiarity with CX and UI/UX principles and their application in modern software design.
• Excellent communication skills with the ability to explain technical challenges and solutions to non‑technical stakeholders.

Desired Skills

• Experience with migrating monolithic architectures to microservices or other modern architectures, exposure to best practices and containerization technologies such as Docker and Kubernetes.
• Familiarity with automated testing frameworks and tools.
• Experience with the following tools:
  Docker, Keycloak, Jenkins, Terraform, Ansible, Open Search, Elasticsearch, Gitlab.
• 5+ years experience with relational databases and ORM technologies, experience with Elastic Search or Open search a plus.
• Familiarity working in Agile / SCRUM Development environments

ECS is an equal opportunity employer and does not discriminate or allow discrimination on the basis any characteristic protected by law. All qualified applicants will receive consideration for employment without regard to disability, status as a protected veteran or any other status protected by applicable federal, state, or local jurisdiction law.

ECS is a leading mid‑sized provider of technology services to the United States Federal Government. We are focused on people, values and purpose. Every day, our 3300+ employees focus on providing their technical talent to support the Federal Agencies and Departments of the US Government to serve, protect and defend the American People.