Ruslan Kryzhanivskyi

Medidata (outstaffing, via Transcenda) Platform for processing and integrating clinical trial data from multiple external systems into validated analytics-ready datasets for internal reporting and downstream research workflows. — Built batch data pipelines for ingesting structured clinical data from external APIs, CSV/Excel files, and internal exports — Designed ETL workflows using Python and Spark to clean, normalize, deduplicate, and validate heterogeneous healthcare datasets — Used S3 as a raw/staging data lake and loaded curated datasets into Snowflake for analytics and reporting — Orchestrated data pipelines in Airflow, including ingestion, transformation, retries, dependency management, and scheduled runs — Implemented incremental loading strategies and data quality checks to handle updates, corrections, and late-arriving records — Optimized Spark transformations and Snowflake queries for performance, storage efficiency, and cost control — Worked with sensitive structured data, ensuring consistency, traceability, and auditability across pipeline stages Stack: Python, SQL, Databricks (Spark), Airflow, Snowflake, AWS S3, Parquet, REST APIs, CSV/Excel

Workiva (outstaffing, via Transcenda) Platform for financial reporting and compliance, focused on collecting, processing, and transforming data from multiple external sources into analytics-ready datasets. — Built data ingestion pipelines to collect financial data from external APIs and cloud storage (CSV/Excel files in GCS) — Developed ETL/ELT workflows using Python and SQL to clean, normalize, and standardize heterogeneous data — Loaded raw data into BigQuery and designed layered datasets — Used PostgreSQL as a metadata store to manage pipeline state, track processed data, and support incremental loading logic — Implemented data transformations using dbt to produce aggregated and reporting-ready tables — Orchestrated data pipelines using Airflow, managing dependencies and scheduled workflows — Optimized BigQuery queries by reducing scanned data, applying partitioning and filtering strategies — Ensured data quality through validation checks and handling inconsistent or incomplete data.

Platform for workforce management with real-time user activity tracking, role-based access control, and event-driven notifications across teams. — Built and maintained fullstack features using React and Node.js — Developed REST/GraphQL APIs for managing users, teams, roles, and permissions — Designed and implemented data models for user activity and access control — Implemented event-driven processing for user actions (role updates, team changes) using Kafka — Used Kafka to decouple notification and audit logging services from core application logic — Optimized API performance and database queries for handling concurrent user activity — Migrated state management from Redux (saga) to GraphQL (Apollo) Stack: TypeScript, Next.js, Node.js, GraphQL (Apollo), Kafka, MongoDB, REST APIs

[Outstaff at "LUKOIL"] Corporate web application for an international gas station network.

— Implementation of administrative panel for bookmaker events. (React, Redux) — Implementation of a mechanism for managing redirects on the landing-page; — Built single page applications (SPA), responsive web design, full screen, UI using HTML5 (Pug) grid layouts, CSS3 (SASS) media queries. — Implementation of themes and plugins for wordpress

— Designed dynamic and browser compatible pages using HTML5, CSS3, jQuery, and Javascript. — Build websites using WordPress. — Development expertise with custom post types, custom fields, plugins and themes for high-traffic Wordpress sites