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Senior Mechanical Engineer

Prototyping + Manufacturing

Rotterdam • Full-time • On-site

Spiral Hydrogen is building a rotating, bubble-free electrolyzer. We are now taking it from TRL 4 to a TRL 6-7 pilot: progressively larger prototypes.

At the heart of it is the cell. The pilot alone needs a few hundred good ones. They have to come out identical, not nearly identical.

You would join our mechanical engineering team, currently two people, inside a core team of ten. This role is hands-on: a large share of the mechanical and manufacturing work is yours.

What you will do

Build progressively larger prototypes and carry them toward the TRL 6–7 pilot
Optimize the subcomponents: electrodes, liquid and gas channels, sealing on a machine that rotates, vibration
Design and build the test rigs that tell you which subcomponent is failing.
Build the fixtures, jigs and tooling that hold tolerance, and decide what we make in-house versus what we buy.
Design the pilot so it can become a product: design for manufacturing and assembly, and process windows that still hold at hundreds of units.

You might be a fit if

You have personally machined, assembled, broken and fixed real machines.
Several years building physical hardware in a startup or another fast-iterating small team.
You think about manufacturability early: tolerance analysis, design for manufacturing and assembly, injection molding, high-repeatability industrial robots, etc.
Personal projects that let us see you like building things

Electrolyzer or hydrogen experience is useful but not required. Adjacent backgrounds translate well: fuel cell or battery cell manufacturing, precision components, high-volume assembly.

Logistics

Location: on-site in Rotterdam, Netherlands
Time commitment: full-time
Team: you plus two other mechanical engineers, ten people in total, founder-led
Ownership: high. A large share of the mechanical work is yours
Compensation: competitive salary + equity for early employees
Process: 2 to 3 interview rounds, 1 test task
Start: as soon as possible