Senior Mechanical Engineer

Full-time, In-person | Somerville, MA | 135K - 175K USD a year

Humanity wastes or burns $50 billion worth of recyclable materials every year – contributing to 50 trillion microplastic particles in our environment, toxic methane emissions, and millions of tons of greenhouse gases. Recycling is not broken because people do not care; it is broken because the systems that support it have failed to keep up.

rStream is changing that. We're building the technology infrastructure that the waste management industry has never had: smart, autonomous tools that reduce operational friction, and create new economic incentives around sustainability. rStream is building systems and processes to make the facilities management more efficient and profitable.

We're hiring a Senior Mechanical Engineer to own the rSort platform from prototype to production. Hardware is the backbone of this technology. Our autonomous sorting equipment operates in demanding real-world environments where mechanical precision and integration directly determine how effectively materials are collected and separated for remanufacturing.

At rStream, your work won't just be noticed; it will directly make the world cleaner and more efficient. If you're a bold, systems-minded engineer who wants to build hardware that operates in the real world at scale, you'll thrive here.

As Senior Mechanical Engineer, you will:

• Lead hardware development and new invention on a world’s first vision guided, redeployable, autonomous waste processing machine
• Direct system design work, including functional requirements, detailed design, verification plans, and build-and-test procedures to design the rTrailer from concept to full scale manufacturing
• Get your hands dirty—designing, building, and testing every subsystem of the rSort platform
• Oversee manufacturing strategies and incoming inspection plans for components and assemblies
• Support the field service team with troubleshooting and fixing hardware problems
• Balance design elegance with execution risk as our company ramps up toward commercialization
• Work cross-functionally with the hardware, software, and management teams to develop and maintain hardware system features and revision roadmap
• Lead and mentor junior-level engineers and technicians to help the team grow

The successful candidate will have:

Required:

• BS (MS preferred) in Mechanical Engineering or a related field
• Minimum of 5 years of hands‑on, robotics or hardware experience
• Expert in CAD design (Solid Works preferred), FEA, and DFx (Design for cost, test, manufacturing)
• Experience with manufacturing methods like laser cutting, machining, sheet metal, 3D printing, and other rapid prototyping
• Hands‑on experience in automation and the integration of custom and commercial components into complex electro‑mechanical systems
• Independently execute hardware/software integration testing and first‑pass debugging
• Demonstrated success launching industrial products to market
• Known for being a team player and willing to help with all type types of work including handling and sorting trash
• In‑person at rStream's Headquarters, Greentown Labs, Somerville MA

Preferred:

• Experience with bulk material handling system, waste processing technology and/or industrial equipment design and manufacturing
• PLC programming and industrial communication protocols (Ether Net/IP, PROFINET, Modbus)
• Familiarity with computer vision, cameras and image processing
• Hands‑on experience with embedded system bring‑up, including firmware flashing, log capture, and isolating hardware
• Familiarity with Python for test scripting and debugging hardware interfaces such as sensors, processors, device communication, and signal timing
• Prior experience at a startup or innovation team
• Excellent communication, people, and organizational skills
• A “Startup Attitude”: quick learner, passionate, nimble, and adaptable- you get creative when the answer is not obvious

Why Join rStream?

We recognize that there is more to work than the day‑to‑day responsibilities. In addition to a collaborative, high‑performing team environment, we’re pleased to offer competitive compensation rates; flexible work hours; and the opportunity to quickly accelerate…