{"id":3347182,"url":"https://alion.io/job/jetcool-principal-thermal-mechanical-engineer-2","title":"Principal Thermal Mechanical Engineer","company":{"id":4392590,"name":"JetCool","domain":"jetcool.com","url":"https://alion.io/company/jetcool-2","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":null},"role":"Industrial Engineering","role_family":"Industrial Engineering","seniority":"lead","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Littleton, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":153500,"max":211000,"currency":"USD","period":"year","gross":null,"usd_annual":211000},"salary_estimate":null,"experience_years_min":7,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[],"status":"live","first_seen_at":"2026-10-27T17:33:43Z","employer_posted_date":"2026-10-27","last_verified_at":"2026-10-28T23:59:22Z","board_verified":true,"closed_at":null,"days_open":1,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":1},"description":"At JetCool, a Flex company, we’re at the forefront of liquid cooling innovation, delivering advanced solutions that empower our partners in AI and high-performance computing. United by a shared purpose, our teams are pushing the limits of what’s possible and tackling complex challenges.\nA career at JetCool offers the opportunity to make a real impact by helping build smarter, more sustainable data centers. Together, we’re not just advancing technology - we’re redefining cooling standards to create a more sustainable tomorrow.\nJob Summary\n\nTo support our extraordinary teams who build great products and contribute to our growth, we’re looking to add a Principal Thermal Mechanical Engineer located inLittleton, MA.\nReporting to theMechanical Development Associate Principal Engineer the Principal Thermal Mechanical Engineer will play a pivotal role in the early phases of product development and serving in a guidance capacity through product maturation. Our products drive sustainability across the data center infrastructure by allowing higher coolant temperatures and by driving more complete heat capture for liquid cooling. The Principal Mechanical Engineer will provide technical leadership, mentorship, and hands-on expertise in mechanical design, fluid dynamics, and heat transfer but also work closely with customers in communicating the art of the possible with JetCool technology and building a strong customer relationship on a technical level.\nWhat a typical day looks like:\nLead the architecture, design, analysis, and optimization of complex fluid and thermal systems-including pumps, fluids, tubing, heat exchangers, and associated components-for advanced computing and processing platforms.\nOwn mechanical and fluid system deliverables from concept through production, ensuring designs meet performance, reliability, manufacturability, and compliance requirements.\nServe as a technical partner to customers and external collaborators, supporting system-level integration of fluid solutions into broader product architectures.\nDrive simulation, analysis, and test efforts to validate fluid flow, pressure drop, thermal performance, and material compatibility across operating conditions.\nDevelop, review, and approve engineering requirements, specifications, and technical documentation in accordance with applicable industry standards and regulatory expectations.\nLead and influence design reviews, presenting technical tradeoffs, risks, and recommendations to cross-functional teams, customers, and senior stakeholders.\nIdentify technical gaps and emerging challenges, advocate for targeted research and development, and lead exploratory efforts that build foundational knowledge and intellectual property.\nEstablish and promote best practices in fluid system design, analysis, and documentation, contributing to a strong engineering culture and continuous improvement.\nProvide technical leadership, mentorship, and guidance to engineers across experience levels, supporting professional development and raising overall team capability.\nContribute to new product innovation by evaluating emerging technologies, industry trends, and alternative architectures to drive differentiated fluid system solutions.\nSupport the resolution of complex technical issues throughout the product lifecycle, including development, qualification, production, and field support as needed.\nThe experience we’re looking to add to our team:\nMinimum of 7+ years of experience designing and engineering fluid systems in data center thermal management and cooling, automotive, medical, or nuclear industries, including at least 3+ years of direct experience with Coolant Distribution Units (CDUs).\nDeep expertise in fluid dynamics, thermodynamics, and heat transfer, with strong application of first principles engineering.\nProven track record of new product development in thermal or fluid systems, including concept development, performance analysis, validation testing, and experimental design.\nStrong analytical and problem solving capabilities, with demonstrated ability to troubleshoot and optimize complex fluid systems across development and production phases.\nDemonstrated technical leadership within a structured product development environment, with clear ownership of mechanical design deliverables from concept through release.\nExperience leading and mentoring development teams, driving technical direction, coordinating cross functional efforts, and ensuring alignment to product requirements and schedules.\nAccountability for product level mechanical execution, including leading design reviews, resolving technical risks, and ensuring designs meet performance, reliability, manufacturability, and compliance requirements.\nStrong communication and technical documentation skills, with the ability to clearly communicate complex concepts to technical teams and senior stakeholders.\nBO18\nWhat you'll receive for the great work you provide:\nFull range of medical, dental, and vision plans\nLife Insurance\nShort-term and Long-term Disability\nMatching 401(k) Contributions\nVacation and Paid Sick Time\nTuition Reimbursement\n\nApplication Deadline:\nApplications for this job position will be accepted for at least five days following the job posting start date below and continuing until the end date below or until the position is filled. This posting may close sooner due to application volume.\nJob Posting Start Date 10-27-2026 Job Posting End Date 12-31-2026\n\nThe base pay range for this position is provided below. The final base rate offered will be determined using job-related, non-discriminatory criteria, including but not limited to experience, qualifications, geographic location, education, external market data, and internal equity.\n$153,500.00 USD - $211,000.00 USD AnnualJob Category\nDesign, Process & Technology EngineeringIs Sponsorship Available?\nNoJetCool is an Equal Opportunity Employer and employment selection decisions are based on merit, qualifications, and abilities. We do not discriminate based on: age, race, religion, color, sex, national origin, marital status, sexual orientation, gender identity, veteran status, disability, pregnancy status, or any other status protected by law. We're happy to provide reasonable accommodations to those with a disability for assistance in the application process. Please email  and we'll discuss your specific situation and next steps (NOTE: this email does not accept or consider resumes or applications. This is only for disability assistance. To be considered for a position at JetCool, you must complete the application process first).","description_format":"text","description_chars":6638,"description_truncated":false,"requirements":{"experience_years_min":7,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity","Life insurance","Professional development"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Servers & Data Center Hardware","Computer Components","High-Performance Computing"],"lifecycle":[{"event":"open","at":"2026-10-27T17:33:43Z"}],"visa":[],"liveness":{"score":86,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.86,"p_room":1,"age_days":0,"expected_fill_days":27,"reasons":["conf:6","win:early"],"computed_at":"2026-10-28T05:59:10Z"},"pay":{"stated_usd_annual":211000,"is_top_pay":true},"html_url":"https://alion.io/job/jetcool-principal-thermal-mechanical-engineer-2","json_url":"https://alion.io/job/jetcool-principal-thermal-mechanical-engineer-2.json","meta":{"generated_at":"2026-10-29T01:22:53Z","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":1991,"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":4392590},"rest":"https://alion.io/mcp/rest/get_company?id=4392590"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fjetcool-principal-thermal-mechanical-engineer-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%2Fjetcool-principal-thermal-mechanical-engineer-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%2Fjetcool-principal-thermal-mechanical-engineer-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/jetcool-principal-thermal-mechanical-engineer-2\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fjetcool-principal-thermal-mechanical-engineer-2"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3347182}},{"tool":"search_jobs","arguments":{"company":"jetcool.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3347182},"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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