{"id":2985243,"url":"https://alion.io/job/castelion-embedded-software-engineer-intern-fall-2026","title":"Embedded Software Engineer Intern - Fall 2026","company":{"id":1795053,"name":"Castelion","domain":"castelion.com","url":"https://alion.io/company/castelion","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":null},"role":"Hardware","role_family":"Hardware","seniority":"intern","employment_type":"internship","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":[],"countries":[],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"RTOS","optional":false}],"status":"live","first_seen_at":"2026-09-07T17:04:36Z","employer_posted_date":"2026-09-16","last_verified_at":"2026-10-24T12:02:12Z","board_verified":true,"closed_at":null,"days_open":46,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":46},"description":"Why Castelion, Why Now \nCastelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability. \nThis is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function. \nEmbedded Software Engineer Intern - Fall 2026\nCastelion is seeking motivated and talented Embedded Software Engineering interns for Fall 2026. You'll help create the software that drives and simulates our missile systems, from low-level firmware on microcontrollers to high-level integration and testing tools. You'll work alongside experienced embedded, hardware, and flight systems engineers to design, implement, test, and debug real systems in the loop. \nYou won't be writing throwaway code; your contributions will directly support our rapid prototyping and real-world tests.\nResponsibilities\nDevelop, test, and debug low-level firmware for embedded systems and flight hardware\nWrite and integrate device drivers for sensors, actuators, and missile subsystems\nBring up new hardware, test boards, and debug at the intersection of electrical and software layers\nCollaborate cross-functionally with hardware, GNC, and flight test teams to ensure robust integration\nParticipate in design reviews, hardware-in-the-loop tests, and on-the-bench bring-up and validation\nDocument your work clearly and share learnings to improve team knowledge and future designs\nBasic Qualifications\nCurrently pursuing a BS or MS in Computer Engineering, Electrical Engineering, Computer Science, or a related technical field\nRising junior, senior, or graduate student at the time of the internship\nStrong C/C++ programming skills for embedded systems\nExperience with microcontrollers or SoCs (ARM, AVR, MSP430, PIC, etc.)\nFamiliarity with developing in bare-metal or RTOS environments\nUnderstanding of board bring-up and debugging fundamentals\nSome familiarity with common protocols: SPI, I2C, CAN, UART, Ethernet, etc.\nU.S. Person status required (due to ITAR regulations)\nPreferred Skills and Experience\nExperience integrating analog/digital hardware with firmware\nFamiliarity with missile systems, defense technology, or aerospace components.\nStrong interest in working in a startup environment with high-impact projects.\nCastelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details. \nOther Duties \nPlease note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice. \nAdditional Eligibility Requirements \nThis position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. \nAffirmative Action/EEO Statement \nCastelion is an Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law. \nCastelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact . Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law. \nCastelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation. \nEAR/ITAR Requirements \nThis position requires access to export-controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export-controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls.","description_format":"text","description_chars":5094,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":true,"languages":[]},"benefits":[],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Missiles","Defense Manufacturing"],"lifecycle":[{"event":"open","at":"2026-10-21T08:14:48Z"}],"visa":[],"liveness":{"score":12,"band":"cold","label":"Long shot","p_open":1,"p_active":0.434,"p_room":0.28,"age_days":46,"expected_fill_days":22,"reasons":["conf:2","velocity","win:tail","crowd:junior,brand"],"computed_at":"2026-10-24T06:02:35Z"},"pay":null,"html_url":"https://alion.io/job/castelion-embedded-software-engineer-intern-fall-2026","json_url":"https://alion.io/job/castelion-embedded-software-engineer-intern-fall-2026.json","meta":{"generated_at":"2026-10-24T12:05:47Z","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":17375,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-25T00:00:00Z"}},"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":1795053},"rest":"https://alion.io/mcp/rest/get_company?id=1795053"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcastelion-embedded-software-engineer-intern-fall-2026"},{"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%2Fcastelion-embedded-software-engineer-intern-fall-2026"},{"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%2Fcastelion-embedded-software-engineer-intern-fall-2026"},{"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/castelion-embedded-software-engineer-intern-fall-2026\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcastelion-embedded-software-engineer-intern-fall-2026"}]}