Machine Learning Engineer

RaySearch is expanding in the field of machine learning and is looking for a Machine Learning Engineer with strong software engineering skills to join our head office in Stockholm. Joining our team provides you with a unique opportunity to innovate and develop software that improves the lives of cancer patients around the world.

About the job

You will be part of an agile team developing innovative solutions using machine learning algorithms to automate and improve future cancer treatments. As a member of the ML Planning team you will develop cutting-edge deep learning methods to accurately predict radiation dose distributions that will be deployed at cancer clinics worldwide.

In radiation therapy, treatment planning is the process of determining how to deliver a precise dose of radiation to a tumor while minimizing exposure to surrounding healthy tissue. This is a complex optimization problem that requires careful balancing of clinical goals. Our deep learning models predict 3D dose distributions directly from patient anatomy (CT images and structure sets), enabling clinicians to rapidly generate high-quality treatment plans for techniques such as VMAT and IMRT. The predicted dose serves as input to downstream optimization, significantly reducing the time and expertise needed to produce clinically acceptable plans.

You will

Your day-to-day work will involve training, evaluating and operationalizing deep learning models for dose prediction. This includes analyzing results using clinical metrics such as dose-volume histograms (DVH), ensuring that predictions meet acceptance criteria for organs at risk (OARs) and target volumes. You will work with real clinical datasets and iterate closely with medical physicists and oncologists to validate model performance against clinical standards.

Your focus will be on the machine learning algorithms as well as on developing, maintaining, and improving the production code base in RayStation. Our models are integrated into RayStation, a treatment planning system used by clinics globally, so engineering rigor matters as much as model accuracy. We value engineers who write clean, testable, well-structured code and who take ownership of the full lifecycle from research prototype to clinical deployment in a regulated medical device context.

You will work closely with domain experts, system developers and product owners as well as leading cancer centers to understand the product and develop tools that will make a real difference.

Your profile

You are someone who genuinely loves both research and coding. You read papers for fun, get excited about new architectures and training techniques, and then want to immediately implement and test them. You are not just an ML practitioner who trains models, you are a strong software developer who cares about code quality, system design, and building things that last. You write code that others can read, review, and extend with confidence.

You are autonomous and self-driven. Given a problem, you take ownership: you research the landscape, form a plan, and execute without needing to be guided through every step. You know when to dig deeper on your own and when to pull in a colleague. You are comfortable making decisions, and you communicate clearly about what you are doing and why.

You take pride in delivering high-quality results and thrive in a dynamic, fast-paced environment. You contribute to a positive team atmosphere and take responsibility for your work. Above all, you care about building software that makes a meaningful impact for healthcare professionals and their patients.

Experience & skills

Requierments

• M.Sc. in Computer Science, Machine Learning, or equivalent
• Minimum 4 years of professional experience in software development, machine learning, or a related field
• Excellent understanding of machine learning techniques and algorithms
• Strong programming skills in Python with emphasis on writing clean, maintainable, production-quality code
• Solid software engineering practices: version control, code review, testing, CI/CD awareness
• Experience using deep learning frameworks such as PyTorch or TensorFlow
• Solid knowledge of data structures, algorithms, statistics, and applied mathematics
• Comfort working in large, collaborative code bases and contributing to shared architecture decisions
• Excellent spoken and written communication skills in English

Meriting

• Experience using deep learning for computer vision
• Experience in model development: Transformers, CNNs, U-Nets, or relevant architectures for dose prediction
• Experience with MLOps tooling (experiment tracking, model registry, deployment pipelines)
• Experience fine-tuning and post-training LLMs using Full SFT / LoRA, DPO, RLHF, with custom data curation and evaluation pipelines
• Contributions to open source projects
• Familiarity with C# and/or systems-level languages
• Experience working in regulated or safety-critical software environments (e.g., medical devices, automotive)
• Interest in or exposure to radiation therapy or medical physics

Our Culture 

At RaySearch, we share a passion for innovation and the fight against cancer. Our team consists of dedicated experts who strive to deliver exceptional results through collaboration, attention to detail, and cutting-edge technology. We take pride in our role as a leader in cancer treatment, developing solutions that truly make a difference for patients worldwide. 

Our Offer 

We offer a dynamic and inclusive work environment in Hagastaden, Stockholm’s Life Science Hub. Our modern office space includes an in-house gym, yoga classes, and social activities such as ping pong, table football, and after-work events. We also provide a fantastic lunch buffet, daily fika, and a stunning rooftop terrace with a 360-degree view of Stockholm. This comes with a competitive compensation and benefits package. 

Application 

Please apply for the position through the application form below. Selection and interviews will be ongoing. We do not accept applications via e-mail.