LettrLabs is rebuilding itself as an AI-native company, and engineering is where that change goes deepest. We built our own engineering design harness: an AI system that works hand-in-hand with engineers to take requirements and carry a design all the way to final, producible parts, much faster than a traditional workflow.
We are looking for a Staff or Principal Mechanical Design Engineer to do two things at once. You will design LettrLabs' next-generation production automation platform. And you will shape the harness itself, deciding how real engineering judgment gets encoded into a tool that makes every engineer here faster.
This is a rare chance to define how hardware gets designed in the AI era, while shipping real machines to a real production floor, at a pace traditional workflows can't match.
This is a hands-on, individual contributor role reporting to the CTO. It is on-site in Los Angeles, in the office five days a week.
What you'll doOwn the mechanical design of LettrLabs' production process machinery and next-generation automation platform as we work to fully automate our production, from open-ended problem statement through build, commissioning and deployment of production machinery on our floor.
Turn ambiguous business and operational needs into clear system and subsystem requirements, then generate concepts, run trade studies and drive down-selection.
Take designs through architecture to release, using our design harness as your primary toolchain.
Drive material and process selection for performance, cost, manufacturability and service life.
Define and run validation: analysis, prototyping, test plans and design reviews that prove the design works before it ships.
Act as a principal user and co-designer of our design harness. Find where it falls short, define what good looks like, and work with our AI and software engineers to iterate and build sound engineering practice into it.
7 to 15+ years in a design-centric engineering role, primarily mechanical. Mechatronics/aerospace backgrounds with a strong mechanical core are welcome. Level (Staff or Principal) will be set based on experience and fit.
A track record of designing complete systems end to end, through production, commissioning and deployment. You have seen your hardware run, broken it and fixed it.
Deep experience with a phase-gate or stage-gate design process: requirements, concept, trade studies and down-selection, preliminary and critical/detailed design reviews (PDR, CDR/DDR), and release.
Strength in turning open-ended problems into clear, testable requirements and concepts at the system and subsystem level.
Deep knowledge of metals, polymers and composites, and sound judgment in material and process selection.
Strong mechanical fundamentals: statics, dynamics, mechanics of materials, tolerancing, mechanisms and DFM/DFA. You make quick, pragmatic calls from first principles, then drill into analysis or test to close and validate the design. Rapid, AI-driven development depends on this judgment.
Experience at a hard tech company known for engineering rigor and speed, such as aerospace, automotive, robotics, or industrial and factory automation.
Background in production automation equipment, motion systems, or high-throughput machinery.
Working knowledge of electromechanical integration: motors, actuators, sensors, controls, and their interfaces with the mechanical system.
Familiarity with GD&T, FEA, and design for reliability and serviceability.
Experience scripting or building tools (Python or similar) to automate engineering work.
Most engineers will spend the next decade watching AI change how hardware is designed. Here, you get to build that change yourself. Your engineering judgment becomes part of a tool that multiplies the whole team, and you prove it out on machines that run our production every day.
If you have taken systems from a blank page to a working floor, and you want to help define what world-class engineering looks like in an AI-native company, we want to talk to you.
Come help us build a better way to design hardware, and the automation platform it was made for.
LettrLabs USA: $180,000 USD - $225,000 USDBenefits
Medical, dental, and vision coverage
Equity in a fast-growing company
401(k) plan.
Flexible PTO and paid holidays
On-site gym
Pet-friendly
Free daily lunch, team off-sites, and happy hours
Located in the heart of Marina Del Rey, a walkable neighborhood with easy access to shops, restaurants, and the marina
Actual base salary offered will be determined by: experience, skills, and work location. This range is for base salary, our total compensation includes equity and benefits. We welcome you to apply even if your expectations are outside our listed range.
LettrLabs is committed to creating a diverse environment and is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.
LettrLabs is committed to providing reasonable accommodations for qualified individuals with disabilities in our job application procedures and throughout employment. If you need assistance or any accommodation, please let us know.
LettrLabs does not accept unsolicited resumes from recruiters or employment agencies without a fully executed recruitment agreement in place. In the absence of such agreement, LettrLabs reserves the right to pursue and hire any candidates without an obligation to pay fees. Agencies are requested not to contact LettrLabs hiring managers or employees regarding recruiting services.
Skills Required
- 5+ years of experience in mechanical design and product development
- Deep, hands-on experience with motion systems and core components (belts, pulleys, gears, bearings, shafts)
- Working expertise in sheet metal design and associated manufacturing methods (bending, CNC machining, laser cutting, waterjet, additive manufacturing)
- Strong command of Design for Manufacturing and Design for Assembly (DFM/DFA)
- Strong fundamentals in mechanical engineering (statics, dynamics, mechanics of materials, tolerancing)
- Proven experience with FEA and hand calculations to validate design decisions
- Track record of owning complete mechanical systems and sub-systems from requirements through commissioning
- Experience working directly with vendors and suppliers throughout design and manufacturing
- Ability to build and test prototypes rapidly and iterate toward production-ready designs
- Bachelor's degree in Mechanical Engineering or a related field
- Master's degree in Mechanical Engineering or a related discipline
- Experience in robotics, automation, or industrial machinery
- Proficiency with SolidWorks, NX, or similar CAD platforms and PDM/PLM systems
- Familiarity with GD&T (ASME Y14.5) and tolerance stack-up analysis
