{"id":3363159,"url":"https://alion.io/job/sosi-senior-application-developer","title":"Senior Application Developer","company":{"id":5998,"name":"SOSi","domain":"sosi.com","url":"https://alion.io/company/sosi","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"SmartRecruiters","truth_index":{"grade":"C","score":58,"open_postings":223,"ghost_share":0.704,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":31,"computed_at":"2026-10-29T05:49:05Z"}},"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":["Fort Belvoir, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":140000,"max":155000,"currency":"USD","period":"year","gross":null,"usd_annual":155000},"salary_estimate":null,"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":".NET","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"C#","optional":false},{"name":"CI/CD","optional":false},{"name":"Configuration Management","optional":false},{"name":"GCP","optional":false},{"name":"JavaScript","optional":false},{"name":"MS SQL","optional":false},{"name":"Rest API","optional":false}],"status":"live","first_seen_at":"2026-10-27T19:56:06Z","employer_posted_date":"2026-10-27","last_verified_at":"2026-10-29T18:29:56Z","board_verified":true,"closed_at":null,"days_open":1,"trust":{"level":"ok","repost_count":0,"flags":["company_stale"],"days_open":1},"description":"Founded in 1989, SOSi is among the largest private, founder-owned technology and services integrators in the defense and government services industry. We deliver tailored solutions, tested leadership, and trusted results to enable national security missions worldwide.\n Overview:\nSOSi is seeking a highly qualified Senior Application Developer to join our team on site in Fort Belvoir, VA, in support of our government customer. In this role, the Senior Application Developer will serve as a technical expert responsible for the design, development, integration, and maintenance of complex software applications. The position requires a strong proficiency in .NET Core and extensive experience supporting the operation, enhancement, and modernization of the ITCD (Information Technology and Compliance Directorate) family of applications. The ideal candidate excels in system integration, collaborates effectively across teams, delivers high-quality solutions, and provides mentorship to junior developers. This role is best suited for someone who is proactive, detail-oriented, and committed to building reliable and scalable systems.\nEssential Job Duties:\nDesign, develop, test, and maintain high-performance software applications.\nAnalyze business requirements and translate them into technical specifications.\nLead the architecture and design of application components and integrations.\nReview code for accuracy, quality, and adherence to best practices.\nTroubleshoot and resolve complex technical issues across the application stack.\nCollaborate with cross-functional teams, including product managers, QA, and DevOps.\nContribute to process improvements, automation, and development standards.\nMentor junior developers and support team knowledge sharing.\nStay current with emerging technologies and recommend solutions when appropriate.\nSupport the project manager in overseeing project operation, planning, and execution.\nFormulate objectives and levels of effort through research and fact-finding with customer representatives and project managers.\nBe responsible for the software development life cycle from planning to implementation to testing and documenting, to deployment and maintenance.\nAssist the project manager and client in developing a schedule/timeframe for each project to ensure each one is executed efficiently and in a timely manner.\nCreate and maintain complete and accurate documentation on all supported applications.\nOversee technical issues related to the operation, maintenance, and modification of GOTS application.\nWork with customer stakeholders to design or customize software with a focus on optimizing operational efficiency.\nApply knowledge of hardware and/or software engineering principles.\nDesign and/or customize software for client use to optimize operational efficiencies.\nMonitor application performance and perform application changes to optimize performance.\nAnalyze and design GOTS applications and systems with a focus on improving functionality and stakeholder usability.\nProvide evaluations and recommendations of GOTS applications and systems to provide solutions to complex technical challenges.\nFollow all applicable agency policies, procedures, and regulations.\nProvide technical guidance to lower-level developers and engineers.\n Bachelor’s degree or postgraduate degree in engineering, scientific, technical, or business management disciplines from an accredited college or university.\nA minimum of 5 years of technical supervisory experience in an application/software development environment.\nAn active in scope Top Secret security clearance, or Secret with the ability to obtain a Top Secret.\nExperience with GOTS applications such as ARMIS, AAO, ACOTD, FACTS, MDR, or ADAMS.\nExperience with Microsoft SQL and the .NET framework.\nExperience with Configuration Management processes including Change Control Boards (CCB).\nAbility to schedule, track, and perform across multiple concurrent projects.\nMust have demonstrated the ability to communicate with a variety of stakeholders in multiple formats.\nMust possess baseline and computing environment certifications for IAT-II IAW DoD 8570.01-M (CCNA-Security, CySA+, GICSP, GSEC, Security+, CND, or SSCP).\n5-8+ years of professional experience in software or application development.\nStrong proficiency in modern programming languages and frameworks (such as C#, JavaScript, .NET, or similar).\nHands-on experience with cloud platforms and services (AWS, Azure, or GCP).\nProficiency with REST APIs, microservices, and application integration patterns.\nSolid understanding of relational and NoSQL databases.\nExperience with CI/CD pipelines, version control systems, and automated testing.\nStrong analytical, problem-solving, and communication skills.\nAbility to work independently while supporting team goals.\n Work Environment:\nNormal office conditions.\nCore hours of operation are Monday through Friday, 0600 - 1700.\nOn government site within Fort Belvoir, VA.\nNo hybrid or remote availability.\nCompensation: $140K - $155K yearly.\nWorking at SOSi:\nAll interested individuals will receive consideration and will not be discriminated against for any reason.","description_format":"text","description_chars":5162,"description_truncated":false,"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":[{"language":"English","level":"All levels","optional":false}]},"benefits":[],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["IT Infrastructure & Networking Services","Military Logistics","Translation Services","Intelligence"],"lifecycle":[{"event":"open","at":"2026-10-27T22:04:19Z"}],"visa":[],"liveness":{"score":63,"band":"ok","label":"Likely open","p_open":1,"p_active":0.632,"p_room":1,"age_days":1,"expected_fill_days":31,"reasons":["conf:0","stale_co","velocity","win:early","comp:brand"],"computed_at":"2026-10-29T05:49:05Z"},"pay":{"stated_usd_annual":155000,"is_top_pay":false},"html_url":"https://alion.io/job/sosi-senior-application-developer","json_url":"https://alion.io/job/sosi-senior-application-developer.json","meta":{"generated_at":"2026-10-29T18:50:37Z","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":27963,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-30T00:00:00Z"}},"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":5998},"rest":"https://alion.io/mcp/rest/get_company?id=5998"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fsosi-senior-application-developer"},{"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%2Fsosi-senior-application-developer"},{"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%2Fsosi-senior-application-developer"},{"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/sosi-senior-application-developer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fsosi-senior-application-developer"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3363159}},{"tool":"search_jobs","arguments":{"company":"sosi.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3363159},"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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