Senior Mechanical Engineer — Robotic Platforms

About Gritt Gritt is building physical AI for outdoor construction. We’re developing a generalized foundation model for construction tasks — pick-and-place, transport, and assembly across materials like PV modules, rebar, cinder block, and beyond — and the robots that put that model to work on real infrastructure-scale job sites. We start with utility-scale solar because the scale and repetition are ideal for learning, but the technology is general: representations learned on one site transfer to the next task, the next material, the next trade. We’re backed by top-tier investors, founded by robotics and AI experts from CMU, Stanford, and MIT, and moving fast to put machines in the field. Zooming out, our ambition is bigger than any single trade: we’re working toward a superintelligence construction platform for the physical world — the kind of general capability civilization will need to build much-needed infrastructure at the pace this moment demands. The Role You’ll own the mechanical integration of our robots onto heavy mobile base platforms — skid-steers and tracked vehicles in the 10,000 lb class — and lead programs that take systems from prototype to repeatable field deployment across construction environments. Our arms are heavy, our payloads are heavier, and our operating conditions run from Arizona desert heat to sub-zero winter cold. You’ll make hard tradeoffs on structure, mounting, sealing, thermal, and serviceability, and you’ll make them fast. Because our platform is general-purpose, you won’t be designing for one task forever. The same base robot needs to handle different end-effectors, payloads, and workflows as we expand across construction. Designing for that kind of reconfigurability — without giving up ruggedness — is a core part of the job. This is a hands-on senior role. You should be equally comfortable in CAD, on the shop floor with a torque wrench, and at a job site debugging a harness failure at 6 a.m.. What You’ll Do - Lead mechanical integration programs that mate robotic arms and payloads to skid-steer and tracked vehicle platforms — structural mounting, load paths, power/data routing, and service access. - Design and specify heavy-duty mechanical systems — mounts, brackets, enclosures, actuators, end-effectors — built to survive continuous outdoor duty cycles on active construction sites. - Architect platforms for reconfigurability so we can adapt across construction tasks (PV, rebar, block work, and future applications) without rebuilding from scratch each time. - Own the environmental strategy: IP67-rated enclosures, gasketing, connector selection, thermal management across roughly -20°F to 120°F+, and ingress protection against dust, mud, rain, and snow. - Design, route, and validate wire harnesses and cable assemblies — strain relief, chafe protection, connector selection, service loops, and harness documentation a contract manufacturer can actually build. - Integrate sensor and lighting packages (cameras, LiDAR, IMUs, work lights, indicators) with attention to field-of-view, vibration isolation, cleanability, and serviceability. - Drive DFM, DFA, and DFS (design-for-service) from the first CAD review, not as an afterthought. - Run structural analysis (hand calcs and FEA) on critical load-bearing components; own the validation plan — vibration, shock, thermal, ingress, EMI — and see it through test. - Work directly with machine shops, sheet metal vendors, and harness houses. Release drawings, manage ECOs, and hold vendors to spec. - Go to the field. Diagnose failures, instrument systems, and carry learnings back into the next revision. What We’re Looking For - 7+ years of mechanical engineering experience, with meaningful time at a robotics, autonomous systems, or heavy equipment company that scaled real hardware into the field. - Direct experience integrating robotic arms, actuators, or heavy payloads onto mobile platforms — skid-steers, tracked vehicles, AGVs, off-road equipment, or equival