Lead Software Engineer - Photonic Ecosystem (f/m/d)

Your mission

Location: Stuttgart or Munich, Germany
Type: Full-time, hybrid (max. 1-2 days remote work per week)

The future of AI computing builds on light. Q.ANT is building photonic processing systems that compute with light - delivering a scalable, energy-efficient alternative to transistor-based architectures for next-generation AI and HPC applications.

As Lead Software Engineer, Photonic Ecosystem (f/m/d), you will own Q.ANT’s presence and credibility in the open source software ecosystem. Your mission is to make photonic computing accessible out of the box - ensuring that default installations of frameworks like PyTorch, JAX and vllm can leverage Q.ANT’s photonic hardware without friction. You will drive the photonic enablement of base libraries and AI frameworks from design through upstream acceptance and long-term maintenance, and serve as Q.ANT's trusted focal point in open source development communities. In this role, you will bridge internal teams - algorithms, compiler, device control, infrastructure, and system architecture - with the requirements of the external ecosystem.

What You Will Do

• Own the photonic enablement of the open-source software ecosystem - drive integration of Q.ANT’s hardware capabilities into base libraries (OpenBLAS, Eigen, numpy) and AI frameworks (PyTorch, JAX, TensorFlow, llama.cpp, vllm)
• Get code accepted into upstream repositories and package managers so that default installations support Q.ANT hardware out of the box - and maintain it long-term
• Serve as Q.ANT’s focal point for open-source software projects - build trust, demonstrate reliability, and represent Q.ANT professionally in development communities such as the PyTorch community
• Guide ecosystem partners of Q.ANT on design, development, upstreaming, and maintenance of their code and packages; deliver technical briefings and training to partners and internal teams
• Enhance the common native photonic standard library, ensuring frictionless, vendor-agnostic use across the software ecosystem
• Align closely with internal teams - algorithms, compiler, device control, infrastructure, system architecture - and bridge external community requirements back into Q.ANT’s development roadmap

Your profile

• Proven experience in open-source software development (5+ years) with a demonstrable track record - contributions, maintainership, and sustained community engagement; verifiable via GitHub profile
• Strong experience developing AI or compute frameworks (2+ years) – significant contributions to projects such as PyTorch, TensorFlow, JAX, llama.cpp or vllm, ideally across multiple AI open-source projects
• Strong Python skills for framework development, integration, and ecosystem tooling - non-negotiable
• Deep knowledge of AI algorithms - neural network operations, linear algebra operations, and their implementation in compute frameworks
• Solid understanding of hardware acceleration architectures (such as GPUs) and performance optimisation - foundational for enabling photonic hardware in software frameworks
• Solid grounding in open-source development processes and tooling - GitHub, CI/CD pipelines, software test frameworks, package distribution frameworks
• Strong ownership, communication, and commitment - you drive ecosystem enablement end-to-end, represent Q.ANT externally with clarity and professionalism, and sustain effort through long upstream contribution cycles
• Proficiency in C/C++ or Rust for performance-critical components is desirable
• API design, testing, and documentation skills are a plus
• Fluent in English; German language beneficial

Why us?

• Make impact at scale: Help solve one of computing’s biggest challenges - making growing demand in compute and sustainability go hand in hand
• Work on the leading edge: Photonic AI acceleration technologies that will define the next decade of computing - already validated in production HPC environments
• Own your work from day one: Shape design and code of software, client solutions, and public collaterals on your own, with direct impact on product success and the future of AI infrastructure
• Fast-track your growth: Work on challenges with few industry precedents - every problem you solve becomes new institutional knowledge and potentially industry-defining IP
• Be the multiplier: Your work enables entire developer communities and directly helps clients succeed with photonic computing
• World-class team: Collaborate alongside a passionate, international, cross-functional team of experts in photonics, processor design, and AI software
• Direct access to leadership: Work closely with the company’s founders, including CEO Dr. Michael Förtsch, and the Q.ANT senior leadership team
• Collaborative culture: Innovative work environment that values technical excellence, open communication, and pragmatic problem-solving
• Be part of history: Join at the inflection point where photonic computing transitions from research to mainstream - your contributions will shape this transformation

We’re looking for a software engineer who gets energized by building foundational open source infrastructure, navigating complex upstream contribution processes, and making cutting-edge hardware accessible to the world’s developer communities.

Ready to define how the open source ecosystem runs on photonic computers? We are looking forward to receiving your application!

Q.ANT is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.

About us

Who we are and what we do

Q.ANT is a deep-tech scale-up developing photonic processing solutions that compute natively with light and deliver a scalable alternative to transistor-based systems. The analog co-processors are optimised for complex computations and enable energy-efficient performance for next-generation AI and HPC applications. In collaboration with the Institute for Microelectronics Stuttgart IMS CHIPS, Q.ANT operates its own pilot line for photonic chips, based on the material system Thin-Film Lithium Niobate TFLN. Q.ANT was founded by Michael Förtsch in 2018 and is headquartered in Stuttgart, Germany.