Principal Applications Engineer

COMPANY DESCRIPTION Vertical Semiconductor, a venture-backed MIT spin-out, is leading the development of vertical gallium nitride (GaN) power semiconductors to build the foundational power layer for the next generation of compute and AI. ROLE OVERVIEW We’re hiring a Principal Applications Engineer to lead applications engineering for next-generation vertical GaN power devices (100 V – 2300 V). You will own how Vertical Semiconductor turns device performance into system-level wins for customers: deciding where we invest in applications, reference designs and enablement, and then making it happen. This is a senior role with broad autonomy and a direct line to company leadership. You’ll lead technical engagement with strategic accounts, define the roadmap for evaluation hardware, reference designs, simulation models and technical content, and set the technical standards the applications team works to. You’ll mentor and guide applications engineers from day one, and the role is expected to grow into leading the applications engineering team as the company scales. KEY RESPONSIBILITIES Applications leadership • Define and own the applications engineering roadmap: reference designs, evaluation hardware, models and content. • Set technical direction and standards for applications work. • Mentor and develop applications engineers. • Act as the company’s senior technical voice on applications, making and defending technical decisions independently with customers, partners and internal teams. Customer technical leadership and design-in • Own technical relationships with strategic accounts: translate customer system requirements into device requirements, lead design-in from first evaluation through production and resolve technical escalations. • Be the subject-matter expert for target applications. • Identify new applications and customer opportunities where vertical GaN wins at the system level, and build the technical case for pursuing them. Simulation, modeling and system enablement • Architect and own SPICE and/or PLECS simulation workflows for vertical GaN in realistic converter environments (switching behavior, parasitics, loss/thermal estimation, gate-drive tradeoffs, etc.). • Establish a library of reusable solution templates (topologies, circuit parasitic models, measurement-informed parameters) so the team can rapidly evaluate customer use cases. • Define and drive the system enablement roadmap: application block diagrams, design guidelines, technical notes and simulation models. Evaluation hardware and reference design leadership • Define and lead evaluation boards, demo boards and reference designs from concept to characterization report (requirements, schematic/layout, BOM, bring-up plan, test plan), whether executing directly or guiding others. • Lead system-level bench testing and debug, and drive design optimizations based on measured performance. High-voltage WBG bench characterization • Define system-level characterization methodology for fast-switching WBG devices (as distinct from die- or wafer-level characterization), including switching waveform integrity, thermal performance, parasitic-sensitive measurements and robustness; perform hands-on characterization where needed. • Develop and publish practical design rules for customers: gate drive, layout/loop inductance, protection strategies and measurement techniques. Technical content and technical marketing • Own the technical content program: application notes, design guides, trainings/webinars and other media that make vertical GaN easy to adopt. Cross-functional product influence • Represent customer and application needs in product definition and roadmap decisions. • Provide structured feedback to Device Engineering and Product teams: performance requirements, feature requests, failure-mode learnings and competitive insights. REQUIRED QUALIFICATIONS • 10+ years in applications engineering supporting power semiconductor customers, or in developing or working with a variety of power converters (e.g., isolated DC-DC, inverters, PFC). Experience delivering reference designs or complete converter hardware is a strong plus. • Demonstrated technical leadership: owning strategic customer programs or major projects end to end, setting technical direction with minimal oversight and mentoring other engineers. • Proven bench characterization experience with high-voltage, high-current wide bandgap devices. • Strong understanding of high-frequency power converter design (switching loss mechanisms, magnetics implications, layout/parasitics, gate drive). • Deep familiarity applying SiC and GaN devices in real converters, including best practices. • Proficiency with SPICE and/or PLECS; ability to develop models and quickly evaluate power circuits. • Experience with parasitic-aware layout and EMI-aware design practices for fast-switching power stages. • Strong technical communication: clear written application guidance and confident presentation to customers, partners and executives. • M.S. or Ph.D. in EE (Power Electronics) or equivalent practical experience. Preferred: experience building or leading an applications engineering team, or a record of conference papers, application notes or industry presentations. LOCATION & TRAVEL • Location: On-site in Somerville, MA preferred; remote considered for candidates who can travel regularly to our applications lab. • Travel: ~25% to customer sites and industry events. VALUES & CULTURE FIT Vertical Semiconductor is seeking an engineer who is not only capable of accelerating the technical vision of the company but is also willing to get involved in the day-to-day execution of a startup. The ideal candidate is someone who enjoys tackling complex engineering challenges, is comfortable with a hands-on approach in a collaborative arena and thrives in a startup environment where they can make an immediate impact. We value integrity, initiative, problem-solving, creativity and a passion for creating transformative technology that can change industries and improve the world. COMPENSATION We offer a competitive salary and comprehensive benefits package with participation in our stock option program that is commensurable with candidates’ experience and impact.