Supplier Quality Engineer, Mechanical Systems (m/w/d)

Rondo is accelerating industry's transition to lower-cost, zero-carbon heat and power.

Our Rondo Heat Batteries turn low-cost renewable electricity into continuous, high-temperature heat and power, enabling industrial facilities to replace fossil-fired boilers without costly process changes. The result is lower-cost, zero-carbon industrial energy delivered safely, reliably, and at 98% efficiency.

Rondo is commercially deployed and rapidly scaling, today. Backed by world-class industrial leaders and investors - including Breakthrough Energy, Energy Impact Partners, Rio Tinto, Aramco, SABIC, SCG, TITAN, Microsoft, H&M, and John Doerr - Rondo is building the next generation of industrial energy infrastructure at global scale - and Quality is at the center of how we get there.

We are building a hardware product that has to be right the first time, every time - at scale, across a global supply chain, with no room for per-project redesign or one-off fixes. As Supplier Quality Engineer you will own the quality of our mechanical component supply base across Europe and Asia, covering both metallic and refractory components, ensuring our suppliers can meet the repeatability, traceability, and scale demands of a product that needs to ship like a manufactured good, not a bespoke project. This is not a compliance or audit role. It is a hands-on, technically demanding position for someone who understands how parts are made - whether that's structural metal fabrications or dense refractory bricks - what failure looks like before it happens, and how to build a supply chain that learns.

What You Will Do

• Own supplier qualification for mechanical components - structural, thermal, electromechanical, and refractory - across our European and Asian supply base, including developing and implementing a robust qualification process, and ongoing performance monitoring.
• Be on-site at suppliers when it matters. Witness first articles, investigate escapes, and close corrective actions with the supplier - not just via email.
• Define and enforce incoming inspection standards and acceptance criteria for mechanical parts, working closely with engineering to make sure our specs are actually inspectable and buildable.
• Drive CAPA processes end-to-end when supplier nonconformances occur - root cause, corrective action, verification of effectiveness, re-qualification if needed.
• Act as the quality voice on engineering change - as the product evolves, you assess whether the supply base is ready to execute design changes, define what re-qualification is required before changes are locked, and ensure no change moves forward without a clear quality sign-off on supplier readiness.
• Build and maintain supplier scorecards covering quality, delivery, and responsiveness, with a clear view of which suppliers can scale to multi-GWh/year volumes without becoming a bottleneck.
• Work proactively on supplier development - not just reacting to failures but identifying risk before it hits production, and building supplier capability ahead of volume ramp.
• Partner with engineering and procurement on new component sourcing decisions, with a quality-first view on whether a supplier is qualified not just to deliver the part today but to scale and sustain it.
• Support the in-house scope expansion as Rondo brings traditionally outsourced interfaces in-house - your supply chain lens will be critical in identifying where external risk is being replaced by internal risk that also needs managing.

What You Will Bring

• 5+ years in supplier quality or manufacturing quality in a mechanical or electromechanical hardware environment - castings, fabrications, machined parts, structural weldments, refractory ceramics, or similar.
• Direct experience with refractory materials - dense fired refractories, insulating castables, or ceramic components - including an understanding of their specific failure modes (thermal shock, spalling, dimensional change under firing), inspection methods, and how their quality requirements differ from standard metallic parts.
• Hands-on experience with PPAP, FMEA, control plans, and MSA - and the ability to translate that experience into building equivalent processes from the ground up in an environment where they don't yet exist.
• Strong understanding of mechanical manufacturing processes across both metallic and refractory components: tolerancing, surface finish, heat treatment, welding, forming, firing, sintering - you know how parts are made and where variation comes from.
• Track record of owning supplier corrective actions through to verified closure, not just issuing 8Ds and waiting.
• Comfort working in ambiguous, fast-moving environments where the product is still evolving and the quality system has to evolve with it.
• Experience working across language and cultural barriers with suppliers - Spain-based with willingness to travel to supplier sites across Europe and Asia.
• Fluent in Spanish and English; additional European languages a plus.
• Familiarity with ISO 9001 quality management systems; experience in cleantech, energy, or capital equipment a plus but not required.

What We Offer

• Private Healthcare (Alan Spain)
• Very competitive salary plus equity in a quickly-scaling company
• A centrally-located Madrid office
• An opportunity to impact industrial carbonization on a daily basis

This role is strongly preferred to be located in Madrid, Spain - though strong candidates from other geographies could be considered - and will require up to 75% travel to supplier sites.

Rondo Energy is an equal opportunity employer. We strive to create a supportive and inclusive workplace where contributions are valued and celebrated, and our employees thrive by being themselves and are inspired to do their best work. We seek applicants of all backgrounds and identities, across race, color, ethnicity, national origin or ancestry, citizenship, religion, sex, sexual orientation, gender identity or expression, veteran status, marital status, pregnancy or parental status, or disability. Applicants will not be discriminated against based on these or other protected categories or social identities.

Rondo is committed to the full inclusion of all applicants. If reasonable accommodation is needed to participate in the interview process, please let our recruiting team know.

We proactively work to design hiring processes that promote equity and inclusion while mitigating bias.

Note to Recruitment Agencies: Rondo does not accept unsolicited agency resumes. Furthermore, Rondo Energy does not pay placement fees for candidates submitted by any agency other than its approved partners.