{"id":3490210,"url":"https://alion.io/job/leidos-senior-full-stack-developer-2","title":"Senior Full Stack Developer","company":{"id":7791,"name":"Leidos","domain":"leidos.com","url":"https://alion.io/company/leidos","size_band":"5000+","is_staffing_agency":false,"employer_type":"services","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"B","score":78,"open_postings":285,"ghost_share":0.004,"stale_share":0.867,"repost_share":0.014,"time_to_fill_p50_days":28,"computed_at":"2026-10-31T05:58:55Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Reston, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":131300,"max":237350,"currency":"USD","period":"year","gross":null,"usd_annual":237350},"salary_estimate":null,"experience_years_min":12,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":".NET","optional":false},{"name":"C#","optional":false},{"name":"CI/CD","optional":false},{"name":"FastAPI","optional":false},{"name":"Git","optional":false},{"name":"JavaScript","optional":false},{"name":"Node JS","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Python","optional":false},{"name":"RAG","optional":false},{"name":"React.js","optional":false},{"name":"Rest API","optional":false},{"name":"TypeScript","optional":false},{"name":"Agile","optional":true},{"name":"Docker","optional":true},{"name":"Kanban","optional":true},{"name":"Scrum","optional":true}],"status":"live","first_seen_at":"2026-10-27T00:00:00Z","employer_posted_date":"2026-10-27","last_verified_at":"2026-10-31T00:40:52Z","board_verified":true,"closed_at":null,"days_open":4,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":4},"description":"Leidos is looking for a Senior Full Stack Developer / Senior Software Engineer to guide the technical support, development, and expansion of our core application ecosystem. In this role, you will take immediate hands on ownership of our modern stack built on React.js, Node.js, Python, and PostgreSQL.\nYour initial focus will include overseeing a straightforward, simple transition of existing web applications (internal tools and core applications) into our ecosystem. This is a direct, functional transition without the need for complex, heavy migration planning.\nAs a senior member of the team, you will help scale active applications, design new features, and collaborate with other innovative technology experts to build brand-new software applications from scratch to fill emerging requirements. You will lend your robust engineering skills to support our modern features, including assisting with the integration of AI-driven tools, chat interfaces, workflows, and data pipelines into our core ecosystem. You will work closely within a highly collaborative, fast-moving small team environment.\nTechnical Execution & Application Support\nTechnical Ownership: Act as a core technical lead for all active web applications, taking responsibility for their overall system health, code quality, and technical design.\nApplication Support: Oversee day-to-day maintenance, troubleshooting, and operational support to ensure application reliability.\nSeamless Transitions: Manage the simple, direct transition of core tools into our supported ecosystem with minimal friction.\nGreenfield Development & Innovation\n New Feature & App Creation: Architect and build high-impact features, optimize backend processing scripts in Python, scale Node.js services, and design high-performance APIs (FastAPI/RESTful).\nModern Integration Support: Assist with the development and technical plumbing required for emerging features, including chat interfaces, RAG concepts, and intelligent application components.\nCode Quality & Mentorship: Conduct code reviews, establish testing strategies, and mentor a Mid-Level developer to maintain a pristine codebase.\nFoundational Codebases: Set up and maintain foundational repositories, boilerplates, and clean code standards for the React/Node/Python stack.\nBasic Qualifications\nMust have an active TS/SCI with Polygraph\nBS degree and 12 - 15 years of prior relevant experience or Masters with 10 - 13 years of prior relevant experience. May possess a Doctorate in technical domain.\nDevelops solutions that are highly innovative, and achieved through research and integration of best practices.\nRecommends and develops new technical solutions, products, and/or standards in support of the program’s strategy and operations.\nDuties include computer programming, documenting, managing configuration, testing, and bug fixing involved in creating and maintaining applications and frameworks involved in a software release life cycle and resulting in a software product.\nExpertise in JavaScript/TypeScript Ecosystems: Strong experience building production-grade web applications using React.js and Node.js.\n Python & API Proficiency: Strong experience using Python for backend services, background jobs, or data processing pipelines, with deep knowledge of building robust RESTful APIs (specifically using frameworks like FastAPI).\n Database Design: Strong command of PostgreSQL (or similar relational databases), including schema design, indexing, complex joins, and query optimization.\n C# / .NET Literacy (Read-Only): You do not need to write or maintain C# moving forward, but you must be comfortable reading and understanding legacy structures to help guide simple application transitions.\nModern Tooling: Deep familiarity with Git and CI/CD concepts.\nPreferred Qualifications\n Agile Frameworks: Practical experience working effectively within an Agile-based development environment (Scrum, Kanban, or similar sprint-based workflows).\n AI & Modern Workflow Familiarity: Practical experience or familiarity supporting AI-adjacent application features, such as conversational/chat interfaces, vector databases, or Retrieval-Augmented Generation (RAG) architectures.\n Containerization (Docker): Experience with Docker configurations, container security, or image hardening is a plus, but containerization is not a strict requirement for this role.\nPreferred Soft Skills & Experience\nThe \"Small Team\" Mindset: Thrives in a small team environment where you have high autonomy, direct business impact, and less corporate red tape.\nInnovation & Ideation: Eager to brainstorm with other technical experts to build new platforms and solve fresh problems from the ground up.\nPragmatic Delivery: Focused on shipping clean, working software on time rather than over-engineering complex frameworks.\nIf you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.\nOriginal Posting:\nOctober 27, 2026For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.\nPay Range:\nPay Range $131,300.00 - $237,350.00The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.","description_format":"text","description_chars":5889,"description_truncated":false,"requirements":{"experience_years_min":12,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"phd","optional":false},"security_clearance":true,"languages":[]},"benefits":["Equity"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["National Security","C4ISR","Defense Manufacturing","Engineering Services"],"lifecycle":[{"event":"open","at":"2026-10-29T23:14:50Z"}],"visa":[{"country":"US","licensed_sponsor":true,"evidence":"H-1B filings in 12 months: 50 · green card filings: 24","filings_12m":50,"filings_prev_12m":58,"green_card_filings_12m":24,"median_offered_wage_usd":124257,"route":null,"cap_exempt":false,"checked_at":"2026-10-29T16:27:21+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":24}],"liveness":{"score":63,"band":"ok","label":"Likely open","p_open":1,"p_active":0.632,"p_room":1,"age_days":4,"expected_fill_days":28,"reasons":["conf:5","stale_co","velocity","win:early","comp:brand"],"computed_at":"2026-10-31T05:58:55Z"},"pay":{"stated_usd_annual":237350,"is_top_pay":true},"html_url":"https://alion.io/job/leidos-senior-full-stack-developer-2","json_url":"https://alion.io/job/leidos-senior-full-stack-developer-2.json","meta":{"generated_at":"2026-10-31T09:17:59Z","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_verified","counted_by":"address","units_charged":1,"used_today":14035,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-01T00:00:00Z"}},"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":7791},"rest":"https://alion.io/mcp/rest/get_company?id=7791"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fleidos-senior-full-stack-developer-2"},{"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%2Fleidos-senior-full-stack-developer-2"},{"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%2Fleidos-senior-full-stack-developer-2"},{"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/leidos-senior-full-stack-developer-2\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fleidos-senior-full-stack-developer-2"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3490210}},{"tool":"search_jobs","arguments":{"company":"leidos.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3490210},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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