Machine Learning Engineer

About the role

Quarks is looking for an engineer to join the AI Platform team and lead a new forecasting initiative. You will work on predictive modeling to support marketing, finance, and analytics teams for our flagship dating product, Kismia.

Key facts

What you'll do

• Build and maintain revenue and LTV forecasting models.
• Develop predictive models for marketing budget allocation and targeting.
• Create behavioral models to detect fraud and manage risks.
• Establish financial forecasting as a core internal competency.

Requirements

• Minimum 2 years of experience in ML, Data Science, or predictive modeling.
• Proficiency in Python.
• Expertise in time series forecasting (ARIMA, ETS, Prophet) and tabular boosting algorithms (XGBoost, LightGBM, CatBoost).
• Ability to evaluate models using MAPE, WAPE, or RMSE and perform time-aware validation without data leakage.
• Strong SQL skills for independent data extraction.
• Experience with feature engineering using payment and behavioral data.
• Ability to deploy models into production environments.

Nice to have

• Familiarity with gRPC and protobuf.
• Experience with Vertica, Elasticsearch, or vector search tools.
• Knowledge of LLMs (Gemini, Gemma, OpenAI, Claude) including integration and prompt engineering.
• MLOps skills such as model monitoring and automated retraining.
• Knowledge of K8s and Helm.
• Background in subscription, consumer, or fintech analytics (LTV, churn, cohorts).
• Experience presenting technical data to non-technical stakeholders.

Skills & tools

• Python, SQL, ARIMA, ETS, Prophet, XGBoost, LightGBM, CatBoost, Time-aware validation, Feature engineering.

Practical notes

• Hiring process: Application, recruitment interview, test task, tech interview, final C-level interview, reference check, and offer.
• Benefits include medical insurance, gym compensation, psychologist support, 20 vacation days, unlimited sick leave, winter holidays, and 6 floating holidays.
• Office features: Located near Taras Shevchenko metro station, equipped with workstations, showers, nap room, PlayStation, and treadmill. Includes corporate meals.
• Flexible hybrid schedule available.
• Quarks supports veterans with a dedicated benefits package for adaptation and growth.
• Salary is competitive with performance-based reviews.
• Professional development supported through internal training, external course compensation, and industry events.