The Role 

The Senior Systems Software Engineer will be a member of the core team building the Quantum Key Distribution system. The focus is on high-performance Python services on Linux, algorithm optimization and acceleration (also via hardware offload), and the role spans defining software architecture, integrating with FPGA/embedded subsystems, and turning requirements into reliable, observable software.  

The Senior Systems Software Engineer leads and co-owns the overall internal QKD software architecture and client-facing software API. By setting engineering standards, mentoring, and unblocking delivery, they ensure predictable releases and a strong execution cadence. 

The Responsibilities 

The Senior Systems Software Engineer should expect to work in the following activities. 

• System architecture
  • Leading and co-owning the QKD software architecture: control plane services, key sifting/postprocessing integration, configuration management, monitoring, and external interfaces 
  • Defining module boundaries and service APIs; evolving the system toward clear data/control-plane separation 

• Efficient implementation and hardware/software integration
  • Designing and implementing high-performance Python services on Linux (asyncio, WebSockets, NumPy); profiling and tuning for latency and throughput
  • Developing, profiling, and optimizing QKD sifting and postprocessing algorithms (signal handling/processing, error correction/information reconciliation, LDPC, privacy amplification) to maximize key rate and minimize end-to-end latency; applying algorithmic improvements and implementation techniques (vectorization, concurrency/async, memory/layout tuning, C/C++ extensions, SIMD/CUDA/GPU/FPGA offload where appropriate)
  • Defining and maintaining robust interfaces with embedded/FPGA system components over UART/USB/PCIe/Ethernet; respecting realtime constraints and failure modes 
  • Guiding downstream system integration (WebSockets/gRPC/REST) and ensuring clear contracts and backward compatibility
  • Designing for test – building mocks/simulators and automated test systems 

• DevOps
  • Building and maintaining CI/CD with Docker and GitHub Actions; automated tests, static analysis, artifact management, and release pipelines
  • Establishing observability (structured logging, metrics, tracing) and operational runbooks; improving reliability and debuggability with SLOs/alerts
  • Embedding security and crypto hygiene by default: secure transport, secrets management, key handling, and coordination with cryptography stakeholders
  • Adding performance benchmarking and regression tracking for key rate and end-to-end latency; integrating profiling/flame graphs into CI and enforcing performance budgets 

The Requirements 

The Senior Systems Software Engineer is expected to have the following qualifications and experience. 

• 5+ years of Python development; 3+ years leading or co‑owning service/system architecture for a hardware‑first product 

• Strong Linux async Python (asyncio, WebSockets), concurrency (threads/processes), profiling/tuning 

• Proven custom hardware integration (MCU, FPGA) over UART/USB/PCIe/Ethernet 

• CI/CD with Docker and GitHub Actions; automated testing, static analysis, artifact management 

• Experience with GPU & CUDA acceleration/optimization; SIMD familiarity 

• Production observability (logging/metrics/tracing) and incident/debug practices 

• Working knowledge of relational/key-value/time-series stores (PostgreSQL/Redis/Prometheus)  

• Security by Default mindset: secrets, secure transport, key/crypto hygiene 

• Proficiency in written and spoken English 

• Ability to be on-site in Munich office several times per week 

• Applicants must have the right to work in Germany at the time of application. We do not provide visa sponsorship. 
• Must be eligible to obtain and maintain either (a) a U.S. Secret (or higher) security clearance or (b) an EU SECRET (or national equivalent) personnel security clearance. Employment is contingent on meeting applicable government security requirements; eligibility is determined by the competent authorities.

Good to have: 

• Experience with QKD systems, cryptography, or high‑rate data pipelines  

• Exposure to C/C++ for low‑level interfacing and FPGA/embedded ecosystems  

• Familiarity with gRPC/Protobuf, schema/versioning strategies, and Kubernetes