Senior Mechanical Design Engineer
LettrLabs
| Company | LettrLabs |
| Category | Engineering |
| Location | Los Angeles |
| Remote | On-site (inferred) |
| Employment | Not stated |
| Level | Senior |
| Salary | Not stated by the employer |
| Posted | 30 Jun 2026 |
| Last verified | 2 Aug 2026 |
| Source | Employer career page (greenhouse) |
Description
The Role
LettrLabs is reinventing direct mail. With our own in-house handwriting robotics, we’re challenging traditional direct mail manufacturing from the ground up. We’re looking for a Senior Mechanical Design Engineer to own the mechanical design and development of complex electromechanical systems from concept through production — and to be instrumental in building our next-generation production automation platform.
You’ll take projects end-to-end: translating requirements into robust, manufacturable designs, validating them through analysis and prototyping, and seeing them through to commissioning. You’ll work closely with cross-functional partners in electrical, controls, manufacturing, and quality, as well as external vendors and suppliers. This is a hands-on, high-ownership position for an engineer who is equally comfortable at a whiteboard, in CAD, and on the shop floor.
Why Join Us
Design the machines that make our product possible — you’re not supporting a production line, you’re building it
High ownership from day one: end-to-end accountability for complete mechanical systems, not isolated components
Work alongside a team of engineers who bring the same grit and ownership mindset to every problem
Real exposure to leadership and cross-functional partners — your design decisions are visible and matter
A culture of grit, perseverance, and performance that values engineers who get energized by hard problems
Competitive compensation, growing benefits, and a culture that rewards initiative.
What You Will Own
Own entire mechanical systems and sub-systems across the full product lifecycle — requirements generation, concept development, detailed design, analysis, prototyping, validation, and commissioning
Design precision motion systems incorporating belts, pulleys, gears, bearings, shafts, and related drivetrain components
Develop sheet metal components and assemblies with a strong understanding of manufacturing processes and tolerances
Apply DFM/DFA principles to drive cost, quality, and reliability across every design decision
Perform engineering analysis using hand calculations and FEA to size components, validate designs, and de-risk failure modes
Select appropriate materials and finishes based on structural, thermal, environmental, and cost requirements
Build and test prototypes rapidly to validate concepts and iterate quickly toward production-ready designs
Create and maintain detailed engineering drawings, GD&T, BOMs, and design documentation
Mentor junior engineers and contribute to design reviews and best practices
What Success Looks Like
Mechanical systems delivered on time from requirements through commissioning with minimal rework
Designs that pass validation the first time — rigorous analysis and prototyping reduce costly late-stage surprises
Cross-functional partners describe you as someone who makes integration easier, not harder
Junior engineers improve measurably through your mentorship and design review participation
What You Bring
5+ years of experience in mechanical design and product development
Deep, hands-on experience with motion systems and their core components — belts, pulleys, gears, bearings, and shafts
Working expertise in sheet metal design and the 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 drive and validate design decisions
A 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
Bachelor’s degree in Mec