Senior Data Engineer

About the Position

Simulmedia is looking for an experienced and dynamic Senior Data Engineer with a curious and creative mindset to join our Data Services team. The ideal candidate will have a strong background in Python, SQL, and large-scale data pipelines. This is an opportunity to join a team of amazing engineers, data scientists, product managers, and designers who are obsessed with building the most advanced TV and streaming advertising platform in the market. As a Senior Data Engineer, you will design, build, and operate the data platform that powers the company: pipelines that ingest and transform very large datasets from external data partners, data models that the whole company queries, and services that make that data available to internal products. You will work on a team that empowers the other teams to use our huge amount of data efficiently.

Location: Ukraine is mandatory. Our offices are located in Kyiv and Lviv. Teams are located in Kyiv and Lviv and primarily work remotely with occasional offline meetings.

Responsibilities

• Design and build batch data pipelines that ingest, validate, and transform multi-billion-row datasets from external data providers and internal systems
• Model complex real-world data: dimensional models, reference data, and temporal data whose attributes change over time (e.g., slowly changing dimensions), and evolve those models safely as upstream sources change their schemas and semantics
• Develop and operate workloads on our lakehouse platform (Databricks / Spark / Delta) and our data warehouse (Redshift), including migrating existing pipelines from the warehouse to the lakehouse
• Orchestrate pipelines with Airflow: scheduling, dependencies, retries, backfills, and alerting
• Prove correctness, not just completion: design parity checks and reconciliation queries when replacing an existing pipeline, run large historical backfills, and investigate data discrepancies down to the row level
• Build and maintain Python services and REST APIs that serve data to internal products
• Optimize for performance and cost: query tuning, table design, workload management, and right-sizing compute
• Own what you ship: monitor production pipelines, participate in incident triage and root-cause analysis, and harden systems so the same failure does not happen twice
• Collaborate cross-functionally with product managers, data scientists, and stakeholders across the company to deliver on the product roadmap
• Work within an Agile team that releases cutting-edge new features regularly
• Take a high degree of ownership and freedom to experiment with new technologies to improve our software

Requirements

• Bachelor's degree in Computer Science, Computer Engineering, relevant technical field, or equivalent practical experience
• 7+ years of work experience as a data engineer
• Proficiency in Python and using it as the primary development language in recent years
• Expert-level SQL: comfortable writing, reading, and tuning complex analytical queries against very large tables, and debugging why two result sets disagree
• Hands-on experience with a distributed data processing platform (Spark/Databricks strongly preferred; EMR, Snowflake, or BigQuery also relevant) and with a columnar data warehouse (Redshift, Snowflake, BigQuery, ClickHouse, etc)
• Ability to design complex data models: normalized, dimensional, and temporal (slowly changing dimensions, effective-dated records, point-in-time correctness)
• Experience with workflow orchestration tools (Airflow or similar): building DAGs, managing dependencies, and running backfills
• Experience integrating third-party data feeds: handling schema drift, late or missing deliveries, vendor data-quality defects, and versioned reference data
• Experience building REST services in Python (FastAPI, Flask, etc)
• Experience developing, maintaining, and debugging problems in large server-side code bases
• Working knowledge of AWS (S3, IAM, ECS, or similar compute) and Docker
• Good knowledge of engineering best practices and testing (unit test, integration test, code review, CI/CD)
• The desire to take a high level of ownership of the things you work on
• Ability to learn new things quickly, maintain a high bar for quality, and be pragmatic
• Must be able to communicate with U.S.-based teams
• Experience with Delta Lake / medallion lakehouse architectures is a plus
• Experience migrating legacy pipelines between platforms with strict parity requirements is a plus
• Experience with advertising, media, or measurement industry data is a plus
• Ability to communicate effectively with the U.S.-based teams and work 11:00 AM - 8:00 PM EEST (11:00 - 20:00)

Our Tech Stack

• Almost everything we run is on AWS (S3, ECS, EMR, RDS, and more)
• Python is our primary language; SQL is everywhere
• Databricks (Spark, Delta Lake) is our lakehouse platform; Redshift and Postgres are our warehouses and operational databases
• Airflow orchestrates our pipelines
• Docker for packaging; GitHub Actions and Jenkins for CI/CD
• Grafana, Sentry, and OpenSearch for observability
• Datasets measured in billions of rows

We Offer

• Opportunity to work with cutting-edge technologies
• Collaborative and innovative work environment
• Competitive compensation package
• Flexible working hours

About the Company

Simulmedia is a leading company in the TV and streaming advertising platform space. We are dedicated to building the most advanced advertising platform in the market, leveraging the latest technologies and data science to deliver superior results for our clients.