Senior Data Scientist

TL;DR

Senior Data Scientist: Building and refining machine learning models, designing statistical experiments, and driving measurable business outcomes with an accent on algorithm design, model evaluation, and experimentation. Focus on developing robust predictive models, controlled A/B testing, and collaborating cross-functionally to deliver product impact.

Location: Must be based in Spain for this fully remote role

Company

hirify.global is a profitable, PE-backed scale-up operating an online services marketplace across multiple countries, currently transforming from lead generation to a subscription-based marketplace platform.

What you will do

• Design, develop, and refine machine learning models including regression, tree-based, ensemble, and advanced algorithms
• Translate exploratory insights into structured modeling approaches and proof of concepts
• Design and execute statistical offline simulations and controlled A/B tests ensuring statistical robustness
• Define success metrics aligned with business objectives and evaluate model performance
• Identify and mitigate risks such as bias, data leakage, and confounding in experiments
• Collaborate with Product, Engineering, and Data teams to prioritize opportunities and communicate complex results clearly

Requirements

• Must be based in Spain
• 3-4 years experience building and iterating machine learning models with large complex datasets
• Strong academic background in Statistics, Mathematics, Computer Science or related quantitative discipline
• Experience with A/B testing, experimental design, and model evaluation metrics
• Proficient in Python and libraries such as NumPy and Pandas
• Experience with cloud data infrastructure like BigQuery and AWS (S3, SageMaker)
• Excellent communication skills to explain technical concepts to technical and non-technical audiences

Nice to have

• Experience in two-sided marketplaces or complex environments
• Familiarity with ranking metrics and optimization in high volume marketplaces
• Practical experience with large language models and generative AI evaluation frameworks
• Understanding of MLOps principles including deployment, monitoring, and retraining

Culture & Benefits

• 25 days paid holiday plus extra days after 3 and 5 years
• Fully remote with up to 20 days per year to work from anywhere globally
• Annual €550 Learning & Development budget
• Access to mental health and wellbeing platform Oliva
• €250 allowance for home office technology

Hiring process

• Screening call with Talent Partner
• Hiring Manager interview
• Technical interview with live case discussion
• Values interview