ML Researcher

Python

ML Researcher

Python
Prosta 51, Warszawa

On The Spot Development

Full-time
B2B
Senior
Remote

Job description

We bring startups and disruptive tech companies to the local market, offering engineers the opportunity to work on innovative, high-impact products. Join us and become a member of their R&D team while we take care of employment, HR support, a benefits package, and an enjoyable work environment.


We’re looking for ML Researcher to join the team at a performance-marketing agency that works across more than 25 industry verticals. They focus on using advanced data analytics and tailored creative strategies to drive conversions — the agency handles everything from lead generation and campaign optimisation (through search, social media and newer platforms) so their clients can focus on growth. 


Responsibilities

  • Develop, train, and evaluate ML models, with a focus on tabular, predictive, and ranking models

  • Contribute to production-ready modeling pipelines, ensuring models are robust, scalable, and optimized for deployment

  • Perform data wrangling, feature engineering, and dataset preparation for modeling at scale

  • Translate hypotheses into measurable experiments and actionable insights

  • Collaborate with cross-functional teams to integrate ML models into production systems

  • Continuously monitor, optimize, and refine models for accuracy, efficiency, and business impact


Requirements

  • Strong hands-on experience with tabular ML models (XGBoost, LightGBM, CatBoost, logistic regression, etc.)

  • Proven experience with data wrangling, feature engineering, dataset preparation

  • Experience training, tuning, and evaluating models at scale

  • Solid understanding of model validation

  • Strong Python skills and familiarity with ML libraries

  • Ability to translate hypotheses into measurable experiments

  • Experience working closely with data engineering pipelines


Nice to Have

  • Experience with inference engineering: packaging models, building inference endpoints, optimizing latency

  • Exposure to model monitoring: drift, data quality checks, performance monitoring

  • Experience with containerization (Docker) and serving frameworks (FastAPI, Flask, TorchServe, Bento, etc.)

  • Experience deploying ML models in production environments

  • Prior experience with ranking, scoring or optimization models


Benefits

  • Work in a highly professional team. Informal and friendly atmosphere in the team

  • Paid vacation — 20 business days per year, 100% sick leave payment

  • Equipment provision

  • Partially compensated educational costs (for courses, certifications, professional events, etc.)

  • Legal and Accounting support in Poland

  • Ability to work from our comfortable downtown office in Warsaw

  • 5 sick days per year

  • Medical insurance (after the end of the probationary period)

  • English and Polish classes 2 times a week (online)

  • Bright and memorable corporate life: corporate parties, gifts to employees on significant dates



Tech stack

    English

    B2

    Python

    advanced

    Machine Learning

    regular

    ML

    regular

Office location

Published: 15.12.2025

About the company

On The Spot Development

On The Spot Development to firma specjalizująca się w tworzeniu oprogramowania na zamówienie. Oferuje wsparcie w zakresie developmentu dla startupów oraz firm, w tym usługi takie jak Offshore Development Center, Custom S...

Company profile

ML Researcher

Summary of the offer

ML Researcher

Prosta 51, Warszawa
On The Spot Development
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