Job title: Senior Data Engineer (Scala/Spark)
Department: Engineering
Reporting to: Engineering Manager
Location: Poland
Purpose of Role
We’re looking for a Senior Data Engineer to join our Market Performance Group and play a key role in transforming large volumes of real-world data into valuable, credible, industry-leading insights & metrics. Your work will directly support our analysts and global customers by powering insights that influence short-term marketing tactics and long-term customer acquisition and retention strategies.
What you will be doing
- Own, build and improve our large-scale data pipelines using Scala for Apache Spark within the AWS ecosystem .
- End to end ownership of complex data transformation and ETL/ELT workflows, ensuring data quality, accuracy, and lineage for critical business metrics
- Design and assemble complex, high-quality datasets that meet business requirements using engineering best practices (version control, CI/CD, etc.)
- Build scalable, resilient data infrastructure and internal tools that support data extraction, transformation, and modeling.
- Work closely with product managers, data scientists and data engineers to understand and translate high-level requirements into actionable, technical data solutions that drive measurable market insights in the telecommunication industry.
- Ensure data quality, reliability, and observability across pipelines and distributed systems.
- Perform deep root cause analysis (RCA) on data discrepancies, pipeline failures, and performance bottlenecks to ensure the integrity and reliability of all delivered data products.
We're looking for:
- 5+ years of experience with building and optimizing big data pipelines using Scala for Apache Spark
- Strong experience with Python and Java for data engineering and production services.
- Advanced proficiency with Relational SQL databases and experience with various analytical databases such as : MSSQL, Postgres, AWS Athena (Presto), Redshift
- 3+ years of experience in writing comprehensive unit and integration tests to ensure data pipeline robustness.
- Experience with core AWS cloud services such as EC2, S3, EMR or equivalent services in GCP/Azure
- Strong analytical skills with proven experience working with large, complex, and unstructured datasets.
- Experience in root cause analysis of data when asked to answer specific business questions
- Proven ability to work effectively with cross-functional teams (ie. Data Science, Product, Analytics)
- Bachelor’s degree in Computer Science, Engineering, or equivalent work experience.
- English (B2 +) and Polish (B2+).
It'd be nice to have:
- Experience with mobile advertising or mobile network data
- Familiarity with workflow orchestration tools (e.g., Apache Airflow).
- Experience designing scalable AWS architectures.
- Experience implementing clustering, classification, or large-scale ML models in production environment.
About Us
Opensignal is the leading global provider of independent insight and data into network experience and market performance. Our user-centric approach allows communication providers to constantly improve their network and maximize commercial performance. Leading analysts, investors and financial institutions place a high value on our independent analysis and we are regular contributors to their reports.
Real network experience is our focus and ultimately that’s what influences customer choice. Our mission is to advance connectivity for all and here at Opensignal, the team is leading the industry in enabling operators to link their network experience and market performance in a way that has never before been possible.
With offices in London, Boston and Victoria, British Columbia, we are truly global, with employees working across four continents and representing over 25 nationalities. We are an equal opportunity employer dedicated to building an inclusive and diverse workforce.
Benefits
We believe we are stronger when we not only celebrate our many differences, values, and voices but include them in everyday practice. Having a diverse and inclusive culture is essential, which is why we offer a flexible approach to work-life balance, operating in a remote-hybrid way. We also offer an attractive range of additional benefits, including:
- 95% remotely - the team meets in the Warsaw office for 1 day/month
- Summer party and other social events
- Comprehensive private health care package for you and your family (dental care included)
- Multisport Card