Senior Data Scientist - Linear Optimization (All Genders)

Location: Krakow, Poland; hybrid work with 60% of the time in the office and 40% at home. The role also allows working abroad for up to 20 days in approved countries.

Salary: 196,300–270,000 PLN

Company

hirify.global is a pet e-commerce company serving more than 12 million customers through a multinational organization with offices across Europe.

What you will do

• Design, develop, maintain, and integrate linear optimization and mixed-integer models into production.
• Create cost-efficient planning tools for outbound logistics across a network handling more than 1,000,000 parcels weekly.
• Analyze data, run simulations, and present actionable insights to engineering, product, and operations stakeholders.
• Contribute across the full software development lifecycle, from ideation and prototyping through deployment, monitoring, and continuous improvement.
• Ensure solution quality and performance through testing, validation, and production monitoring.

Requirements

• Degree in Computer Science, Applied Mathematics, or a related field.
• At least 5 years of hands-on experience solving linear optimization and mixed-integer problems.
• At least 2 years of experience with commercial solvers, preferably Gurobi.
• Strong knowledge of mathematical modeling, simulations, Python, Pandas, NumPy, SciPy, relational databases, and SQL.
• Experience explaining complex technical concepts to non-technical stakeholders.
• Proactive, collaborative approach and willingness to challenge the status quo.

Nice to have

• Experience with forecasting algorithms.

Culture & Benefits

• Self-organized, cross-functional teams working in a mature Agile environment.
• Pair programming, code reviews, knowledge sharing, clean code, DevOps, and continuous learning.
• English is the working language in a diverse organization with colleagues from more than 50 countries.
• Development opportunities, training, wellbeing offers, subsidized transport or bike leasing, and a 20% product discount.
• Hybrid work with the option to work abroad for up to 20 days in approved countries.