Senior Data Scientist

About the Position:

Bluefish is seeking a full-stack Senior Data Scientist who thrives in fast-paced environments and is passionate about building impactful, customer-centric AI solutions. This role is ideal for someone who enjoys owning the entire data science lifecycle—from ideation to experimentation to deployment—and is motivated by driving tangible business and customer outcomes.

You will work autonomously and lead your own projects, collaborating across teams while providing your own technical direction. You should be excited to hypothesize and test ideas, set up your own experiments and pipelines, and ensure that every insight and model you deliver provides real value to both the customer and the business.

What You Will Be Doing:

• Independently lead end-to-end data science projects: from problem definition and hypothesis generation to modeling, testing, and deployment.
• Own your pipeline: design, build, and maintain scalable data workflows and ML systems without needing support from product and engineering teams.
• Drive customer-focused experimentation: design A/B tests and other experiments with a clear focus on improving user experience and product outcomes.
• Identify new opportunities for research and experimentation—bring forward your own ideas, test them quickly, and evaluate business impact.
• Collaborate cross-functionally, especially with engineering, product, and design, while taking full ownership of your project’s goals, execution, and delivery.
• Translate data into strategy: craft clear, actionable insights that directly inform product development and company direction.
• Stay hands-on with cutting-edge tools and models, particularly LLMs and generative AI, and integrate them into production systems when they solve real problems.

What you Bring:

• 5+ years of experience in data science, with a track record of leading and delivering impactful, production-level projects.
• Demonstrated ability to work independently: proactively identify problems, design solutions, and push projects forward with minimal oversight.
• Strong experience with full-stack data science: data wrangling, modeling, validation, deployment, and monitoring.
• Comfortable setting up your own experiments, pipelines, and direction while ensuring alignment with customer and business goals.
• Experience working with LLMs or generative AI in real-world applications.
• Proficient in Python, SQL, and ML frameworks (e.g., Pandas, Scikit-learn, PyTorch, Hugging Face, LangChain, spaCy/NLTK).
• Deep understanding of experimentation techniques: A/B testing, causal inference, and how to interpret results in a business context.
• Ability to balance scientific rigor with business pragmatism—understanding which experiments are worth running and which aren’t.
• Excellent communication skills and the ability to advocate for data-driven decisions across disciplines.
• A mindset of ownership, resourcefulness, and continuous improvement.

About Bluefish:

Bluefish believes that AI represents the next major chapter of the internet – and that consumers will increasingly use AI to consume information and media online. On this new AI internet, brands will need new tools and technologies to tell their stories to consumers online – and a new marketing ecosystem will be created around AI. Bluefish is building the platform that helps brands engage consumers on this new AI channel, with powerful enterprise tools to manage AI brand safety and engage consumers with thoughtful and personalized AI marketing experiences. 

The Bluefish team is a tight-knit group of mar-tech industry veterans who previously helped build foundational ad-tech platforms now owned by Meta and Microsoft. The company is backed by leading AI and data focused investors, including Crane Ventures, BloombergBeta, Firebolt Ventures and Laconia Capital. 

We are a globally distributed team, with business operations based in New York City and engineering based in Berlin. 

Why Bluefish & Our Values:

• Unique opportunity to join on the ground floor of a fast-moving startup building at the center of AI 
• Tackle challenging and abstract problems while disrupting the $300BN legacy mar-tech industry 
• Join an experienced high-performing team where you will have immediate ownership and impact 
• Experience a true meritocracy with significant career growth upside as the business scales 

Our Values:

• Demonstrated grit and resourcefulness—you find creative solutions, adapt quickly, and aren’t afraid to roll up your sleeves in a fast-paced, evolving environment.
• Thoughtful and strategic thinker with the ability to anticipate needs, ask the right questions, and deliver insights that truly drive value.
• Proven ability to collaborate across functions and roles, fostering open communication and shared ownership of outcomes.
• Commitment to craftsmanship—you take pride in delivering high-quality work, paying attention to the small details while keeping the big picture in mind.
• Self-starter with a proactive mindset and a strong sense of accountability—able to drive projects forward independently while staying aligned with team goals.
• Comfortable navigating ambiguity and learning new tools, processes, or technologies to get the job done.