LightFeather is seeking a Senior Full Stack Engineer to support a federal government client in modernizing critical mission systems for DHS ICE. You will own full stack delivery with a focus on translating complex legacy system behavior into clean, scalable software. The current environment includes large legacy systems managing operational workflows such as processing, tracking, and encounter management. These systems carry layers of business rules, manual processes, and tightly coupled functionality. The core challenge is understanding how they work in practice, identifying mission-critical functionality, and translating it into a modern platform-based architecture. The client is adopting Palantir as the target modernization platform. This is a Full Time, Remote Position. Location: Fully Remote (EST hours) Job Type: Full-time Clearance Requirement: U.S. citizenship is required for this position due to federal contract requirements. Candidates must currently hold an active Public Trust and be able to maintain it. This role does not offer sponsorship for a Public Trust — applicants without a current, active Public Trust will not be considered. Responsibilities: Design, develop, and maintain full stack applications supporting modernization of DHS ICE systems. Analyze legacy systems and workflows to identify core functionality vs. unnecessary process overhead. Translate operational requirements into scalable, modern application designs. Develop backend services, APIs, and integration layers connecting legacy environments to modern platforms. Build and enhance user-facing components using modern front-end technologies. Support the full SDLC: analysis, design, development, testing, deployment, and maintenance. Troubleshoot issues across application, integration, and data layers. Collaborate with stakeholders to clarify requirements and improve system behavior. Participate in code reviews and uphold engineering best practices. Required Qualifications and Skills: U.S. Citizenship is required with the ability to obtain and maintain a Public Trust clearance. Bachelor's degree in Computer Science or related field (or equivalent experience). 7+ years of hands-on full stack software development experience. Experience working in complex or enterprise system environments. Strong experience with Java and frameworks such as Spring Boot. Experience designing and implementing RESTful APIs. Experience with front-end technologies including JavaScript, React, HTML, and CSS. Experience working with relational databases and data access patterns. Ability to troubleshoot across multiple layers of an application stack. Experience working in Agile or iterative delivery environments. Ability to analyze and simplify complex systems and workflows. Strong systems thinking and problem-framing capability. Comfort working in ambiguous, poorly documented environments. Ability to distinguish between essential functionality and legacy process bloat. Strong ownership mindset and accountability for outcomes. Effective communication with both technical and non-technical stakeholders. High learning agility and willingness to adopt new platforms and tools. Preferred: Experience with legacy system modernization or transformation efforts. Experience supporting federal or mission-driven environments. Exposure to enterprise data platforms or large-scale system integrations. Experience working in environments where requirements must be derived from real-world usage rather than formal documentation. Why Join LightFeather? At LightFeather, you're not just taking a job — you're joining a purpose-driven team that delivers innovative, mission-critical solutions to make a real difference. You'll work on diverse, meaningful projects that challenge and inspire you, alongside some of the best minds in the industry. LightFeather is an Equal Opportunity Employer. We consider all qualified applicants for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, disability, veteran status, genetic information, or any other status protected by applicable federal, state, or local law.