Senior Data Engineer

Welcome! Super excited you dropped by 🥳 Let's redefine cyber security expertise standards and connect business - community through highly engaging hacking experiences. (Find out more insights about Hack The Box culture in our career site). ✨The core mission of the Senior Data Engineer: You will own and evolve our data pipelines on GCP — building new ones, hardening existing ones, improving data quality, and making clean, trustworthy data available across the organisation. You'll work end-to-end on streaming and batch pipelines, from CDC and event ingestion through transformation, serving, and the feature layer that powers our ML and AI products. Your day-to-day will include designing ELT/ETL processes on BigQuery and ClickHouse, building real-time pipelines on Pub/Sub and Kafka with Dataflow (and where it fits, Flink/Spark), orchestrating workflows with Airflow, and ensuring data is properly cleaned, modelled, and served for analytics, ML training, and online inference. You'll partner with ML engineers on feature pipelines, monitoring data drift, and keeping models well-fed and retrained as needed. You'll consume and build REST APIs, integrate with third-party SaaS sources, and treat infrastructure as code. 🏢 Location & Work Mode: Europe/Greece Choose between fully remote work across Europe or relocating to our Athens Tech Hub with relocation support. Fully Remote / Hybrid (2 days in the office, 3 days remote, plus one month of work from anywhere) - If only in Greece: When hiring in Greece, we're open to candidates from all locations. Those based within 55 km of our Athens office will follow a hybrid work model. For candidates located beyond that radius, a fully remote arrangement is available. ✈️ Relocation We offer a 10% relocation bonus on the annual salary to support your move. In addition, you would benefit from a 50% tax reduction on your income as part of the relocation. We'll support you with accommodation during the first few weeks 🍺 The fellowship you’ll be joining: You will be part of the Data, Analytics & AI team, collaborating closely with Infrastructure, Software Engineering, Product, and ML/AI engineers. We're in the middle of a GCP-native modernisation — migrating away from Snowflake toward BigQuery, Bigtable, Pub/Sub, and Dataflow — so we're looking for someone who's opinionated about clean architecture, allergic to over-engineering, and comfortable owning systems end-to-end. If retiring a legacy warehouse and standing up its replacement sounds like a good time, you'll fit right in. ⚔️ Technology tools & weapons you’ll be using: Cloud & warehouse: GCP, BigQuery, Bigtable, Cloud Storage Streaming & messaging: Pub/Sub, Kafka Processing: Dataflow (Apache Beam), with Flink/Spark where appropriate Orchestration: Airflow (Cloud Composer) Analytical store: ClickHouse Languages: Python, SQL Modelling & quality: dbt, data quality gates Containers & CI/CD: Docker, Kubernetes, GitHub Actions / equivalent Legacy (being retired): Snowflake 🚀 The adventures that await you after becoming Senior Data Engineer at Hack The Box: Design and build batch and streaming pipelines on Dataflow, Pub/Sub, and Kafka feeding BigQuery, Bigtable, and ClickHouse Help drive the migration off Snowflake onto our GCP-native stack — and retire shadow pipelines along the way Own the orchestration layer in Airflow, including SLAs, retries, and data quality gates Model data for analytics and for ML — including feature pipelines that serve both training and low-latency online inference Partner with ML engineers on feature stores, drift monitoring, and retraining workflows Capture requirements from stakeholders and translate them into pragmatic, well-scoped data products Continuously improve data quality, reliability, observability, and cost efficiency Identify new data sources worth acquiring and integrate them cleanly 🏆 Skills, knowledge, and experience points required to unlock the role of the Senior Data Engineer at Hack The Box: Strong data modelling and warehouse architecture skills (dimensional modelling, event-driven, lakehouse patterns) Hands-on experience with GCP data services — BigQuery is a must; Pub/Sub, Dataflow, Bigtable, Cloud Composer are strong pluses Production experience with streaming pipelines on Dataflow/Beam, Flink, or Spark Structured Streaming, ingesting from Kafka and/or Pub/Sub Solid SQL and strong Python — you write production-quality code, not just notebooks Experience with ClickHouse or another columnar OLAP engine in production Workflow orchestration experience with Airflow (or Prefect/Dagster) Comfortable with dbt or equivalent transformation frameworks Experience migrating off legacy warehouses (Snowflake, Redshift, Synapse) onto cloud-native stacks is a plus Working knowledge of ML in production — feature engineering, feature stores, model deployment, drift monitoring, retraining Docker & Kubernetes experience CI/CD mindset, infrastructure-as-code sensibility, and a bias for simple, observable systems Bonus: CDC tooling (Datastream, Debezium), Vertex AI / Feature Store What your Hack The Box adventure will have in store: 🎯You'll have the exhilarating opportunity to contribute to a product that is highly appreciated by users and the cybersecurity community at large 🎯 You'll experience a highly supportive and caring environment, fostering growth, flexibility, and autonomy 🎯 You'll embark on an exciting journey of continuous learning and problem-solving, leveling up as our organization grows 🎯 Most importantly, you'll have a blast at HTB 🥳 because fun is an essential ingredient in our recipe for success! Just wait until you see our global meet-ups! 💰 The gems you’ll be enjoying as a Senior Data Engineer: Private health care Paid paternity leave 25 annual leave days Free lunch & snacks at the office 120€ Ticket Restaurant by Edenred Dedicated budget for training and professional development, participation in conferences Full access to the Hack The Box lab offerings; so you can learn how to hack 😉 State-of-the-art equipment (mac, iPhone, and mobile plan) Flexible WFH (Hybrid Model) - Fully Remote is also an option if you're not an Attica resident Our benefits package is designed to provide strong support to our team, but it may vary depending on location and type of employment (e.g., UK, Greece, or engagement through an Employer of Record). 🗺️ The Quest of Becoming Hack The Box’s Senior Data Engineer: Level 1: To complete level one’s objective, submit your application. Level 2: Meet the Talent Acquisition team. Level’s objective: highlight your past achievements, ambitions, and values. Level 3: Meet the hiring team. Level’s objective: connect with the hiring team and share with them your achievements. Level 4: Complete 2 assignments that align with day-to-day job-related tasks and responsibilities. Part of the assignment is discussing it with the hiring team in a debriefing session, in order to walk the team through your thinking process. Level 5: Congratulations! Not many reach this level 💪. Level’s objective: have a constructive, final conversation with senior leadership to explore the role and your future at HTB. Level 6: You've officially received an offer from HTB! To complete the last level and the Quest, all you need to do is accept the offer. Quest complete. Congratulations, you’re officially one of us 🥳🎉🎇Your next quest: complete the onboarding. Hack Your Career, Today. Join us in this epic adventure of cybersecurity at Hack The Box! 🚀🔒💻 At Hack The Box, we are on a quest to find the most exceptional and enthusiastic talent to join our team. Whether or not you consider yourself a gamer, we value what makes you unique and want to know more about you. This job post provides just a glimpse of the incredible gamified experience our business and consumer customers enjoy through our platforms. So, if you're ready to embark on a journey of growth and adventure, we can't wait to meet you! ABOUT HACK THE BOX Hack The Box is the Cyber Performance Center with the mission to provide a human-first platform to create and maintain high-performing cybersecurity individuals and organizations. Hack The Box is the only platform that unites upskilling, workforce development, and the human focus in the cybersecurity industry, and it’s trusted by organizations worldwide for driving their teams to peak performance. Offering an all-in-one environment for continuous growth, assessment, and recruitment, Hack The Box provides solutions for all cybersecurity domains. Launched in 2017, Hack The Box brings together the largest global cybersecurity community of more than 3 million platform members. Rapidly growing its international footprint and reach, Hack The Box is headquartered in the UK, with additional offices in the US, Australia, and Greece. 🚨 Exciting News: Get the most important updates on HTB’s latest year ! We are super proud to share that HTB’s all three entities across the UK, US, and Greece have been Certified as a Great Place to Work (Oct 2023-Oct 2024). Furthermore, in 2024 the HTB's Greek entity has been listed by the Great Place to Work Institute as the #2 Best Workplace in Greece and #10 Best Workplace in Europe (among Small & Medium Workplaces💪). Take a sneak peek at how it is to be part of HTB and our 2023 Global Retreat. Get more insights about our HTB culture and employee experience by visiting the “about us” section of our site, our career site, and Glassdoor. At Hack The Box, we are committed to fostering a diverse, inclusive, and equitable workplace. We believe that diversity enriches our performance, services, and the communities we serve. As such, we ensure that all job applications are considered solely based on merit, skills, and qualifications. We do not discriminate on grounds of race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. We are dedicated to providing a fair and respectful work environment that reflects our values.