Principal Software Architect — Quantum Platform

<p><strong>Location:</strong> Remote within Europe, with regular presence in Bremen</p> <p><strong>Direct Reports: </strong>None initially; technical leadership across the engineering group</p> <h2>Mission</h2> <p>Own the architecture of the software platform on which Constructor Labs' quantum group builds. The platform drives physical quantum hardware end to end — calibration, orchestration, experiment execution and device state — and must work both in our own cloud and on customer premises, including restricted and air-gapped environments. The Principal Architect sets the technical direction, makes the structural decisions, and is the senior engineering voice in a group where research and engineering sit closely together.</p> <h2>Responsibilities</h2> <p><strong>Pillar 1 Platform Architecture</strong></p> <ul> <li>Own the end-to-end architecture across backend services, job orchestration, hardware abstraction and device state management.</li> <li>Define the interfaces between the scientific layer and the platform layer so physicists can work without engineering support.</li> <li>Make and carry the build-versus-buy and framework decisions; document them so they survive the people who made them.</li> <li>Lead the migration of the platform onto the Constructor technology stack.</li> </ul> <p><em>Success Metrics and KPIs: architectural decisions documented and adopted, platform stability, migration delivered to plan.</em></p> <p><strong>Pillar 2 Hands-on Engineering</strong></p> <ul> <li>Write production code in the core of the system, not only design documents.</li> <li>Own the hardest components personally — those where correctness and performance both matter.</li> <li>Set and enforce engineering standards: testing, review, structured logging, dependency governance.</li> <li>Remove single points of failure so no component has only one person who understands it.</li> </ul> <p><em>Success Metrics and KPIs: test coverage, review discipline, bus factor above one on every core component.</em></p> <p><strong>Pillar 3 Working with Research</strong></p> <ul> <li>Work day to day with research physicists, translating experimental workflows into software.</li> <li>Keep the research and engineering collaboration model intact as the group grows.</li> <li>Support the product function with realistic estimates and honest technical constraints.</li> </ul> <p><em>Accountability: research team able to run experiments without engineering bottlenecks.</em></p> <h2>Requirements</h2> <p><strong>Experience</strong></p> <ul> <li>10+ years building production software systems, with real depth in Python, C#/.NET or C++.</li> <li>Distributed systems, job scheduling, and interfacing with instruments or physical hardware.</li> <li>Track record as the senior technical voice in a small team.</li> <li>Delivered software into on-premise and restricted environments, not only cloud.</li> </ul> <p><strong>Skills &amp; Competencies</strong></p> <ul> <li>Able to hold an architecture in your head and explain it simply to people who are not engineers.</li> <li>Comfortable in a scientific domain. A physics degree is not required, genuine interest is.</li> <li>Pragmatic about trade-offs; able to ship rather than perfect.</li> <li>Strong written communication. Decisions that are not written down do not exist.</li> </ul> <p><strong>Education &amp; Languages</strong></p> <ul> <li>Degree in computer science, physics, engineering or equivalent practical track record.</li> <li>Fluent English. German useful, not required.</li> </ul> <h2>What This Role Is (and Is Not)</h2> <p><strong>This role IS</strong></p> <ul> <li>Deeply hands-on, with real authority over technical direction.</li> <li>Central to everything the quantum group builds.</li> <li>A role where you will have peers and a platform behind you.</li> </ul> <p><strong>This role is NOT</strong></p> <ul> <li>A management track role.</li> <li>An architecture-committee or advisory position.</li> <li>A role where someone else writes the hard code.</li> </ul>

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