Hardware Mechanical Engineer - Hybrid

Vannevar is a defense technology company building AI to deter our adversaries. In the 21st century, conflict moves at algorithmic speed and foresight equals firepower. Our agentic AI is purpose-built to compete with China—from cross-Strait conflict to gray zone coercion. Trained on the most mission-relevant datasets in defense, our technology models adversary behavior, simulates campaigns, and recommends the best course of action to decision makers. Our AI systems are some of the most trusted in the industry and actively used on the front lines of the Indo-Pacific to keep the peace and save lives.

Exceptional technology starts with exceptional people. Vannevar is a small agile team combining world-class engineers with veteran strategists who bring deep expertise in defense and tradecraft. We’re building a company defined by mission impact, user empathy, and disciplined growth. In just three years, we grew from $3M to $80M in ARR, achieved early profitability, and reached unicorn status—proving that disruption doesn’t require an ego, and staying power doesn’t mean standing still.

About the role

The sensing team at Vannevar Labs is building a new hardware product that supports a widespread need for low-cost, attritable, and easily coordinated sensing. We’re looking for a Hardware Mechanical Engineer who can take ideas from a sketch on the whiteboard all the way to robust, working systems in the field.

You’ll be the first Mechanical Engineer on the team – setting the tone for how we approach mechanical design, making key technical decisions in your domain, and turning rough concepts into rugged, field-ready hardware. You’ll be part of a cross-functional team of hardware engineers (systems and electrical), software engineers, ML specialists, former military officers, and product strategists working together on this mission-driven product.

If you’re excited about designing hardware from scratch, solving real-world engineering problems in ambiguous environments, and having a huge impact from day one — this is your shot.
This is a hybrid role based in Seattle (3 days/week in office).

What you'll do

• Design and develop rugged enclosures and mounts for sensor-driven devices, ensuring the systems can be deployed in harsh remote environments. Your designs will emphasize passive cooling (thermal management without fans), protection from the elements (vibration, shock, ingress), and easy maintainability for field operators.
• Own the mechanical design process end-to-end – from initial concept and 3D CAD modeling through prototyping and refinement – ultimately guiding contract manufacturers through fabrication and assembly for production runs. You’ll make sure our mechanical parts meet quality standards and are delivered on schedule.
• Build and execute mechanical test plans (thermal, vibration, shock, environmental) on prototypes and production units. You’ll validate that designs meet requirements, analyze failures or weaknesses, and iterate quickly to improve the hardware based on lab tests and real-world field feedback.
• Collaborate closely with electrical and systems engineers to integrate circuit boards, antennas, and other electronics into your mechanical designs. You’ll balance technical requirements (like thermal loads, electromagnetic considerations, and structural support) with operational needs (like serviceability and weight) to achieve an optimal overall system design.
• Work with external partners and vendors to source and fabricate mechanical components. When we utilize external design or manufacturing resources, you’ll interface with them technically and then transition those designs in-house as the product scales.
• Provide mechanical leadership in a small, fast-moving team – establishing best practices in design and documentation, making critical trade-off decisions, and pushing back when necessary to protect technical quality and realistic schedules. In short, you’ll be the authority on all things mechanical, ensuring our hardware is built right.
• Travel up to 20% as needed to support hardware deployments in the field, visit suppliers or manufacturers, and gather hands-on feedback to inform improvements to the mechanical design.

What we look for

• An experienced mechanical engineer who’s taken hardware products from concept to production (and ideally through deployment in the field) – especially in scrappy, ambiguous environments where you had to figure a lot out as you went.
• A builder and problem-solver – comfortable with hands-on prototyping, machining or 3D printing parts, and iterating quickly to fix issues. You thrive in t