{"id":1759643,"url":"https://alion.io/job/reisystems-senior-full-stack-developer-python","title":"Senior Full Stack Developer- Python","company":{"id":1962699,"name":"Reisystems","domain":"reisystems.com","url":"https://alion.io/company/reisystems","size_band":"501-1000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"iCIMS","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":null,"work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Sterling, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":122000,"max_usd":224000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":2745},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agile","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"CI/CD","optional":false},{"name":"Docker","optional":false},{"name":"Embeddings","optional":false},{"name":"Function Calling","optional":false},{"name":"Git","optional":false},{"name":"Human-in-the-Loop","optional":false},{"name":"JavaScript","optional":false},{"name":"LLM","optional":false},{"name":"LLM Guardrails","optional":false},{"name":"Prompt Engineering","optional":false},{"name":"Python","optional":false},{"name":"RAG","optional":false},{"name":"Reranking","optional":false},{"name":"Scrum","optional":false},{"name":"Semantic Search","optional":false},{"name":"Semantic Search","optional":false},{"name":"SQL","optional":false},{"name":"TypeScript","optional":false},{"name":"Angular","optional":true},{"name":"ASP.NET Core","optional":true},{"name":"C#","optional":true},{"name":"FastAPI","optional":true},{"name":"Java","optional":true},{"name":"Kubernetes","optional":true},{"name":"React.js","optional":true},{"name":"Rest API","optional":true},{"name":"Spring Boot","optional":true}],"status":"live","first_seen_at":"2026-10-03T12:15:39Z","employer_posted_date":"2026-10-03","last_verified_at":"2026-10-06T22:44:38Z","board_verified":true,"closed_at":null,"days_open":3,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":3},"description":"Overview\nREI Systems’ mission is to deliver reliable, innovative technology solutions that advance Federal clients' missions and exceed their expectations. Our technologists and consultants are passionate about solving complex challenges that impact millions of lives. We take a Mindful Modernization® approach in delivering our services, including application modernization, grants management, case management systems, government data analytics, and advisory services. This approach, the REI Way, ensures mission impact by aligning our clients' strategic objectives with measurable outcomes through people, processes, and technology. We offer the same commitment to our employees by providing professional development, meaningful projects, and flexibility to spend time with family and friends. We believe employees are at their best when fulfilled in both their professional careers and their personal lives. Learn more at www.REIsystems.com. Employees voted REI Systems a Washington Post Top Workplace in 2015, 2016, 2018, 2020, 2021, 2022, 2023, 2024, and 2025!\nResponsibilities\nPosition Overview\nREI Systems is seeking a mid-senior Full Stack Developer to support technology modernization and digital transformation initiatives for the FDA.\nThe Full Stack Developer will design, develop, integrate, test, deploy, and support secure enterprise applications across the user interface, backend services, APIs, databases, and cloud environments.\nThe ideal candidate combines strong frontend and backend software engineering skills with practical experience building modern web applications, RESTful services, and data integrations. This role is intended for a hands-on engineer who can independently own complex application features while collaborating with architects, product owners, testers, DevOps engineers, database administrators, and business stakeholders.\nResponsibilities\nFull Stack Application Development\nDesign, develop, test, and maintain secure, scalable enterprise web applications that address business and operational requirements.\nDevelop end-to-end application features spanning user interfaces, backend services, APIs, business logic, and data persistence.\nTranslate functional and technical requirements into maintainable application components and reusable software patterns.\nModernize and enhance existing applications while maintaining compatibility with enterprise architecture and integration standards.\nTroubleshoot application defects, integration failures, performance issues, and production incidents throughout the development lifecycle.\nDevelop proof-of-concepts and technical prototypes and transition successful solutions into production-ready capabilities.\nGenerative AI & LLM Solutions\nDevelop applications leveraging Large Language Models (LLMs) and Generative AI technologies.\nBuild and support Retrieval-Augmented Generation (RAG) solutions using enterprise documents, structured data, and approved knowledge sources.\nImplement prompt engineering, prompt templates, grounding, context management, tool/function calling, and structured LLM outputs.\nIntegrate commercial and/or open-source LLMs through APIs and enterprise AI platforms.\nWork with embeddings, semantic search, vector databases, reranking, chunking strategies, and document-processing pipelines.\nDevelop AI-enabled capabilities such as intelligent search, summarization, classification, information extraction, question-answering, and workflow automation.\nImplement appropriate guardrails, monitoring, fallback strategies, and human-in-the-loop processes for Generative AI applications.\nRAG, Knowledge & Data Engineering\nDesign ingestion and retrieval pipelines for enterprise documents and data sources used by AI/LLM applications.\nDevelop data preprocessing, cleansing, transformation, chunking, metadata enrichment, and validation routines.\nWork with relational databases, APIs, document repositories, object storage, search platforms, and cloud-based data services.\nCollaborate with data engineers to establish reliable, governed data pipelines for AI/ML use cases.\nEnsure appropriate handling of data quality, lineage, security, access controls, and source traceability.\nFrontend Engineering\nDevelop responsive, accessible, and user-friendly web interfaces using modern JavaScript/TypeScript practices and component-based frameworks.\nImplement client-side validation, state management, error handling, and reusable user-interface components.\nIntegrate frontend applications with RESTful APIs and enterprise services using secure authentication and authorization patterns.\nCollaborate with product owners, UX/design resources, and testers to ensure application behavior aligns with user and business needs.\nSupport accessibility and usability requirements applicable to federal web applications, including Section 508 considerations.\nBackend Services & Integration\nDevelop backend services and business logic using Python technologies appropriate to the application architecture.\nDesign, develop, document, and maintain RESTful APIs and microservices for internal and external integrations.\nImplement secure service-to-service communication, input validation, exception handling, logging, and transaction management.\nIntegrate applications with relational databases, enterprise APIs, document repositories, and cloud-based services.\nCollaborate with architects and integration teams to support reliable interoperability across enterprise systems.\nData & Database Development\nDesign and work with relational data models that support application functionality, reporting, and integration needs.\nWrite, optimize, and troubleshoot SQL queries and data-access logic for performance, reliability, and maintainability.\nCollaborate with database administrators on schema changes, indexing, data migration, security, and production support.\nApply appropriate data validation, integrity, access-control, and error-handling practices within application workflows.\nCloud, DevSecOps & Deployment\nDevelop and deploy application components in AWS and/or Azure environments in collaboration with cloud and DevOps engineering teams.\nParticipate in CI/CD processes for automated build, testing, security scanning, deployment, and release management.\nContainerize application services using technologies such as Docker and support deployment in cloud-native environments.\nUse application logging, metrics, tracing, and monitoring to support troubleshooting, operational readiness, and performance improvement.\nApply secure software development and DevSecOps practices across the application lifecycle.\nSoftware Quality & Agile Delivery\nDevelop clean, maintainable, testable, and reusable code following established software engineering standards and design principles.\nCreate and maintain unit, integration, API, and automated tests appropriate to the application stack.\nParticipate in code reviews, peer reviews, technical design discussions, and defect resolution.\nWork within Agile/Scrum teams and participate in sprint planning, backlog refinement, demonstrations, and retrospectives.\nMaintain technical documentation for application architecture, interfaces, configurations, deployment, and operational support.\nApplication Security & Federal Compliance\nFollow applicable federal and FDA security, privacy, data-governance, and software development requirements.\nApply secure coding practices for authentication, authorization, input handling, secrets management, data protection, and API security.\nSupport remediation of application security findings identified through code scanning, dependency scanning, penetration testing, or security reviews.\nParticipate in technical reviews and provide documentation required for production deployment and operational support.\nQualifications\nApproximately 5-8 years of professional software development experience, including hands-on full stack application development.\nStrong backend development experience with Python, Java and/or .NET technologies and enterprise application patterns.\nStrong frontend development experience with JavaScript/TypeScript, HTML, CSS, and a modern component-based web framework.\nExperience designing, developing, and integrating RESTful APIs and backend services.\nWorking knowledge of SQL, relational databases, data modeling, and application data-access patterns.\nExperience with Git, branching strategies, code reviews, and modern software development practices.\nExperience with unit testing, integration testing, automated testing concepts, and defect troubleshooting.\nWorking knowledge of CI/CD pipelines and application deployment practices.\nExperience working in Agile/Scrum multidisciplinary development environments.\nStrong analytical, troubleshooting, and problem-solving skills.\nAbility to communicate technical concepts clearly to technical and non-technical stakeholders.\nPreferred Qualifications\nExperience supporting FDA, HHS, or other federal government programs.\nExperience developing and deploying enterprise applications in AWS or Azure.\nExperience with frontend frameworks such as React or Angular.\nExperience with backend frameworks such as FastAPI, Spring Boot, ASP.NET Core, or comparable enterprise frameworks.\nExperience with Docker and containerized application deployment; familiarity with Kubernetes or cloud-native platforms.\nUnderstanding of microservices, event-driven integration, and enterprise application architecture.\nExperience with OAuth 2.0, OpenID Connect, role-based access control, and API security patterns.\nFamiliarity with application performance monitoring, distributed tracing, logging, and observability practices.\nFamiliarity with DevSecOps practices, dependency management, static analysis, and secure software development.\nExperience supporting Section 508 accessibility and federal web application requirements.\nExperience working with sensitive, regulated, scientific, healthcare, or federal data is a plus.\nProfessional Skills\nStrong analytical and critical-thinking abilities.\nExcellent written and verbal communication skills.\nAbility to translate business and user requirements into practical technical solutions.\nAbility to independently own complex development tasks and features while collaborating effectively within a larger technical team.\nStrong attention to detail and commitment to software quality, security, maintainability, and user experience.\nAbility to work across multiple technology layers and troubleshoot issues from the user interface through backend services and data stores.\nAbility to communicate technical risks, assumptions, dependencies, and recommendations clearly.\nStrong documentation, mentoring, and knowledge-sharing skills.\nKey Technologies\nLanguages: Python, Java and/or C#, JavaScript/TypeScript, SQLFrontend: React and/or Angular, HTML, CSSBackend: FastAPI, Spring Boot and/or ASP.NET Core, REST APIs, microservicesCloud: AWS and/or AzureDevelopment: Git, CI/CD, Docker, automated testingData: SQL databases, enterprise APIs, structured dataMethodology: Agile/Scrum, DevSecOps\nIdeal Candidate Profile\nThe successful candidate will be a hands-on full stack developer who is comfortable moving across the application stack rather than working exclusively in frontend or backend development. They should be able to build user-facing features, implement backend services and APIs, work with relational data, troubleshoot integration issues, and collaborate with cloud and DevOps teams to deliver secure production applications.\nThis individual should have sufficient experience to independently own complex features and technical tasks, contribute to design decisions and code reviews, and mentor less-experienced developers while operating under the broader technical direction of solution architects and program leadership.\nEducation: Bachelor’s degree in computer science or a related field.\nClearance: Candidate must be able to obtain and maintain a Clearance.\nLocation: Hybrid (2 Day per week in our Sterling, VA HQ)\nEEO Statement: REI System...","description_format":"text","description_chars":12035,"description_truncated":true,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[]},"benefits":["Professional development"],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Artificial Intelligence","Cybersecurity"],"lifecycle":[{"event":"open","at":"2026-10-03T12:15:39Z"}],"visa":[{"country":"US","licensed_sponsor":true,"evidence":"H-1B filings in 12 months: 39 · green card filings: 9","filings_12m":39,"filings_prev_12m":79,"green_card_filings_12m":9,"median_offered_wage_usd":142813,"route":null,"cap_exempt":false,"checked_at":"2026-10-03T21:08:04+00:00","sources":["US Department of Labor: LCA disclosure data (H-1B, H-1B1, E-3)","US Department of Labor: PERM disclosure data (green cards)"],"filings_for_role_12m":29}],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":2,"expected_fill_days":39,"reasons":["conf:2","velocity","win:early"],"computed_at":"2026-10-06T05:45:30Z"},"pay":null,"html_url":"https://alion.io/job/reisystems-senior-full-stack-developer-python","json_url":"https://alion.io/job/reisystems-senior-full-stack-developer-python.json","meta":{"generated_at":"2026-10-07T00:07:46Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler","counted_by":"address","units_charged":1,"used_today":136,"day_limit":5000,"remaining_today":4864,"minute_limit":60,"resets_at":"2026-10-08T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":1962699},"rest":"https://alion.io/mcp/rest/get_company?id=1962699"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Freisystems-senior-full-stack-developer-python"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Freisystems-senior-full-stack-developer-python"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Freisystems-senior-full-stack-developer-python"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/reisystems-senior-full-stack-developer-python\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Freisystems-senior-full-stack-developer-python"}]}