Data Engineering Tech Lead

About Cosmose AI

We make smartphones smarter. Cosmose is integrated by eight phone makers, capturing first-screen real estate and first-party data to drive over 2 billion daily user interactions in 60+ countries.

Why Join Cosmose AI?

• Global Scale: Build a product natively integrated across eight major OEMs with access to first party data from millions of phones in over 60 countries.
• Elite Talent Density: Work alongside IOI and ACM-ICPC champions.
• High Autonomy, Fast Velocity: Take complete ownership with rapid deployment cycles and a flat org chart.
• Real Ownership: Earn stock options that directly tie your upside to our global growth and success.

We're looking for a hands-on Data Engineering Tech Lead to own the technical direction of our data platform and lead a small team of Data Engineers.

This is a dual role: you'll set technical direction and stay deep in the code, while also leading the team day-to-day - 1:1s, mentorship, technical growth and hiring.

What you'll do

• Own the technical direction of our data platform and make architectural decisions with a clear grasp of their trade-offs and long-term consequences.
• Stay hands-on - design systems, write production code, review implementations and solve the hardest problems yourself.
• Drive initiatives end-to-end - identify important problems on your own, propose solutions and see them through to production.
• Optimize for performance and cost across the platform, from data models and storage to processing and querying.
• Build order in Data - establish clear data contracts, schemas, ownership, documentation, standards and quality practices. You'll also own the data interfaces other teams depend on.
• Solve distributed systems problems - consistency, exactly-once processing, fault tolerance, schema evolution, streaming, storage, scalability and performance.
• Lead and grow the team - through technical direction, reviews, mentorship and regular 1:1s.

What we're looking for

• Strong software engineering background with production experience in Python or Java.
• Deep understanding of distributed systems and the problems that arise when data is processed and stored across multiple systems.
• Strong data engineering experience - pipelines, data platforms, warehouses/lakes and data modeling.
• Ability to make architectural decisions independently and reason about their long-term impact.
• A strong sense of ownership - you find problems and opportunities yourself rather than waiting for a backlog.
• High standards for performance, reliability, cost, data quality and engineering discipline.
• Clear communication of technical decisions and effective work across teams (Polish and English are required)
• Ability to learn new technologies quickly and reason about unfamiliar systems.

Our stack

• Flink, ClickHouse, Iceberg, Spark, Python and Java.
• You don't need experience with all of them - we care more about strong fundamentals and your ability to pick up new technologies and apply them well.

What success looks like:

• The team has clear technical direction and ownership.
• The platform is reliable, performant, scalable and cost-efficient.
• Data contracts, schemas, ownership and documentation are well defined.
• Technical debt and systemic problems are actively surfaced and addressed.
• Data consumers trust the platform and rely on it in their day-to-day work.

We’re building something big—and we’re just getting started.

If you’re excited about shaping the future of AI-powered mobile content, we’d love to meet you.

Be part of the Cosmose story. Apply now!