About Qilimanjaro

Qilimanjaro is building full-stack superconducting quantum computing systems, combining QPUs, cryogenic infrastructure, control electronics, racks, cabling, instrumentation, software and deployment infrastructure. Our Systems & Engineering division turns quantum processors into complete, reliable and scalable quantum computers.

We are looking for a Quantum Hardware Engineer to join our Systems & Engineering division. Why this role matters

Systems & Engineering is the division that turns a quantum processor into a machine that runs reliably, day after day.

We own the setups: cryogenics, wiring, control electronics, racks, instrumentation, thermal and mechanical design, and the Python that drives them. Our machines run on customer sites, not only on our own bench.

Our hardware base is currently growing faster than our team. This is system-level work rather than component design: you decide which part belongs in which line and determine why a chain misbehaves once it is fully connected, rather than designing boards or components from scratch. The qubit is the most sensitive instrument in the building, and it usually reflects the state of the electrical or thermal chain in front of it.

A large part of this role is interpreting that signal and addressing the root cause. Main ownership areas:

Within six months you will take ownership of one setup end to end — its wiring, its cooldowns and its numbers. You become the person the team relies on to confirm whether that setup can be trusted.

The role spans two tracks. No one works in only one of them, as both involve travel and debugging, but you choose the one you would prefer to focus on: Electronics and Instrumentation — room-temperature signal chains, RF and DC. Bench measurement, component characterisation, grounding and noise, control electronics, racks, board and packaging support.

Cryogenics, Vacuum and Thermal — dilution refrigerators, cooldowns, cryogenic wiring and thermalisation, heat loads and thermal budgets, vacuum and leak hunting, mechanical integration, site readiness.

If your preference is genuinely balanced, let us know, and we will place you based on what your hands-on work demonstrates. We're looking for an autonomous, results-oriented profile who thrives in dynamic environments. We value the ability to make sound decisions, take ownership of one's own work, and adapt with agility to the company's shifting priorities. ?Key Responsibilities:

Run cooldowns and warmups on dilution refrigerators, mount and change samples, and build coaxial and DC looms inside the fridge, including thermalisation.

Manage heat loads and thermal budgets, validated against the qubit temperatures we actually measure rather than against the datasheet. Handle vacuum, leak hunting,



pulse tubes, compressors and helium lines.

Characterise bias tees, directional couplers, combiners, filters and low-noise amplifiers on a network analyser, then validate them again under real pulses. Produce grounding maps that are measured before they are drawn, and investigate noise floors that shift when an instrument is connected.

Own racks that other teams depend on: control electronics, lab instruments, parametric and HEMT amplifiers, integrated and validated. Maintain the Python that runs the lab, including our instrument library, a thermal calculator and an RF analysis tool.

Document each job in a concise write-up, clear enough that a colleague can reproduce your work without your involvement.

Travel to client premises for deployment visits several times a year.

Qubit design, chip fabrication, algorithms and the calibration libraries are owned by other teams and fall outside this role.

Who we are looking for:

We are looking for a versatile, hands-on engineer who can approach an unfamiliar setup, measure it and diagnose what is wrong, rather than a specialist in one narrow area. You are comfortable moving between a dilution refrigerator, a network analyser and a Python script within the same week.

This is a hands-on hardware role in our Barcelona lab, focused on diagnosing why hardware that should work does not. It is not a fit for component, chip or board design, quantum algorithms or software, firmware or embedded development, theoretical or simulation work, or fully remote roles. ?Minimum requirements: You have personally identified the cause of a hardware problem, and can name the symptom, the cause, and one measurement that changed once you fixed it.

You have made real hardware work and taken a measurement off a lab instrument with your own hands that you would stand behind. Coursework, thesis work and internships count fully.

Enough programming ability to drive an instrument and analyse its output: Python, MATLAB or LabVIEW. This is not a software engineering role.

A degree in physics, or in electrical, electronic, telecommunications or mechanical engineering, or equivalent hands-on experience. ?Preferred Skills:

Advantageous but not required, and all can be learned on the job:

Cryogenics, vacuum and superconducting devices

GHz measurement and S-parameters

Grounding, shielding and board layout

LTspice, COMSOL, HFSS or AWR





QCoDeS, Qblox, Bluefors

Mechanical CAD and thermal modelling

ESD handling

Spanish and Catalan

We are also interested to hear about something you chose to build, fix or measure on your own initiative. What success looks like after 6 months

You own one setup end to end: you can bring up and validate one signal chain, or run one cooldown from start to finish, and colleagues trust your numbers without needing to repeat the work.

You have identified and resolved one real problem on a live setup, and your write-up prevents the issue from recurring.

You are ready to lead a deployment visit at a client premises. ❤️ Diversity and Inclusion:

At Qilimanjaro, inclusion and equal opportunities are part of our people-centric value. We are committed to creating a workplace where everyone feels valued and empowered to contribute, learn, and belong. Why don’t you join us? ? We offer:

A technically demanding role with real scope from day one, you help define the system, you don't inherit a finished one.

Direct collaboration with physicists, cryogenic engineers, PCB engineers and software developers.

A small team where your decisions are visible and your influence is immediate.

Competitive salary, discussed openly and based on experience.

Benefits: ? Private health insurance

? Cobee flexible compensation (transportation, meals, and childcare support)

⏰ Flexible working hours

? Hybrid work model You will: ? Get the opportunity to build something amazing and unique, something that hasn't been done before

? Work on ground-breaking projects and possibly solve massive challenges on a integral scale

? Be at the intersection of research and industry, where biggest innovations happen

? Make an enormous impact in a dynamic scale-up rather than being a small cog in a big machine

? Work with super smart, knowledgeable and yet, very friendly people in Barcelona, one of the best cities in the world (picture a lot of sun, amazing food and friendly locals)

? Get to be part of a start-up where growth on a company and individual level is the default GDPR (General Data Protection Regulation):

DATA CONTROLLER: QILIMANJARO QUANTUM TECH S.L., B67429670, Carrer de Veneçuela, 74, 08019 Barcelona (BARCELONA), Data Protection Officer: qilimanjaro@delegado- datos.com.PURPOSES: Participation in recruitment processes and reference verification.LEGAL BASIS: Implementation of pre-contractual measures.DISCLOSURES: None are an ticipated.DATA RETENTION: For the duration of the selection process.RIGHTS: You may exercise your rights of access, rectification, erasure, restriction, and data portability with the data controller. In case of any disputes, you may contact the AEPD (www.aepd.es).

📌 Quantum Hardware Engineer (Barcelona)
🏢 Qilimanjaro Quantum Tech
📍 Barcelona