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