Staff Data Scientist
Optimizely AB · Stockholm · Tills vidare · Deadline 2026-10-25
Optimizely AB is seeking a **Staff Data Scientist** to lead technical decisions, mentor team members, and drive the architecture, design, and implementation of robust, scalable machine learning systems. Working collaboratively with cross-functional teams, the role involves independently developing and shipping medium-to-large features, leading projects that address complex challenges, and owning core services and components. Responsibilities also include advocating for machine learning and software engineering best practices, managing project uncertainties, resolving technical alignment issues, and actively participating in hiring and fostering team diversity. Candidates should meet most of the core criteria, including at least five years of hands-on development team experience alongside previous technical leadership. The position requires **excellent Python programming skills**, strong expertise in machine learning, recommender systems, and natural language processing, as well as proven experience delivering scalable ML systems. Familiarity with cloud platforms (AWS, Azure, or GCP), distributed data processing such as Spark, data querying, source control, and a foundational grasp of Generative AI and LLMs are expected. Additional assets include experience prototyping research papers, work with deep learning, reinforcement learning, or applied statistics, familiarity with **A/B testing and data pipelines**, and prior collaboration with data engineers or product managers.
Introduction - Legacy Section
As a Staff Data Scientist, you will play a pivotal role in architecting, designing, and implementing robust machine learning systems while providing guidance and mentorship to team members. With expertise in machine learning, you will lead technical decisions, manage complex projects, and collaborate effectively with cross-functional teams to deploy large-scale projects.
Job Responsibilities - Legacy Section
· Architect, design, and implement robust and scalable machine learning systems
· Develop and ship medium to large features independently
· Support and mentor team members by setting direction and providing guidance and feedback
· Cultivate an inclusive environment, lead meetings effectively, and actively listen to develop empathy
· Engage in high-leverage activities to deliver projects that solve complex problems with increased quality and efficiency in a timely manner
· Be an expert in the relevant areas, lead technical decisions, and own related services and components
· Gain alignment for improvements/redesigns, address conflict maturely, and effectively influence stakeholders
· Work on complex issues, exercise independent judgment, manage project uncertainties, and make tactical decisions
· Collaborate with cross-functional team members to develop and deploy large-scale projects
· Advocate software engineering and machine learning best practices
· Prioritize and balance time and resources, develop iteratively, and address cross-functional problems
· Maintain composure under difficult circumstances, adapt to shifting priorities, demonstrate self-awareness, and deliver timely feedback to peers and manager
· Play a key role in hiring, retaining, and growing diversity in the company
Knowledge and Experience - Legacy Section
Meet most of the following:
· 5+ years hands-on experience in a development team
· Previous technical leadership experience in a similar environment
· Excellent Python programming skills and experience in software development
· Strong understanding of Machine Learning, Recommender Systems and Natural Language Processing
· Strong experience planning, designing, and implementing scalable machine learning systems
· Experience with cloud computing infrastructure (AWS/Azure/GCP)
· Experience with distributed data processing (Spark or similar cloud services)
· Experience with data querying
· Basic understanding of Generative AI and LLMs
· Experience with source control tools (GitHub/GitLab)
· Great ability in conveying complex concepts to a non-technical audience
· Understanding of the ML development life cycle and/or prior experience working with teams of ML Engineers
· Ability to work in an inclusive environment and share our values
· Continuous learning and improvement mindset
Bonus points:
· Experience prototyping ideas discussed in research papers into code that can be assessed and benchmarked
· Experience with Deep Learning / Reinforcement Learning / Statistics applied to Machine Learning
· Experience with A/B testing
· Experience with data processing pipeline frameworks (e.g., Luigi or Airflow)
· Experience working with teams of Data Engineers or Product Managers
· Experience with functional programming concepts and architecture