Senior Software Engineer - JVM Language Clients

About ClickHouse Recognized on the 2025 Forbes Cloud 100 list, ClickHouse is one of the most innovative and fast-growing private cloud companies. With more than 3,000 customers and ARR that has grown over 250 percent year over year, ClickHouse leads the market in real-time analytics, data warehousing, observability, and AI workloads. The company’s sustained, accelerating momentum was recently validated by a $400M Series D financing round. Over the past three months, customers including Capital One, Lovable, Decagon, Polymarket, and Airwallex have adopted the platform or expanded existing deployments. These customers join an established base of AI innovators and global brands such as Meta, Cursor, Sony, and Tesla. We’re on a mission to transform how companies use data. Come be a part of our journey! About the team The Integrations Ecosystem org is the bridge between ClickHouse and the rest of the data world. We build and maintain the connections that make ClickHouse accessible to the developers, data engineers, and analysts who rely on it in production every day. Our scope spans low-level database drivers, ingestion and CDC pipelines, data framework integrations, and BI connectivity — ensuring ClickHouse feels native in whatever stack our users already have. We maintain the official language clients (Python, JavaScript, Java, Go, Rust, C++, C#) and ODBC driver; ship first-party connectors for Kafka Connect, Apache Spark, Apache Flink, dbt, and Airbyte; and own integrations with BI platforms. This role sits on the Language Clients team, which provides the JVM foundation that everything else in the ecosystem is built on. What you'll do As a Senior Software Engineer on Language Clients, you'll be a technical owner of ClickHouse's Java client and JDBC driver, the foundation that our own Connectors team and a long list of external frameworks rely on to talk to ClickHouse. Your primary users are engineers: the Connectors team building ClickHouse connectors for Kafka, Flink, Spark, and others, and the broader JVM ecosystem (data ingestion tools, BI platforms, data visualizations) that consumes the driver directly. Your job is to make sure they have a fast, reliable, well-designed foundation and to treat their feedback as the signal for where the driver goes next. In your first year you can expect to: Own the Java client and JDBC driver end-to-end: roadmap, API design, performance, release engineering, and partner-facing support. Drive throughput and latency work across the client and ClickHouse server Partner day-to-day with the Connectors team as an embedded internal customer: understand what their connectors need from the driver, and ship it. Engage directly with external partners across data ingestion, and data visualization on interoperability, regressions, and roadmap alignment. Ship visible, measurable wins in throughput, stability, and developer experience. We expect you to bring opinions, artifacts, and written proposals to shape where we invest next. About you 5+ years of software engineering experience with a significant portion focused on data-intensive systems: drivers, SDKs, ingestion, CDC, streaming, or analytics. Deep Java and JVM expertise: memory model, GC tuning, profiling, and the ability to reason about throughput and latency at the level of bytes on the wire. Hands-on experience building or substantially extending a library that other engineers depend on. You understand that API design compounds, and that a breaking change in a widely used library is a very different thing from a breaking change in an application. Strong grasp of database fundamentals: SQL, query execution, and analytical/OLAP workloads. Judgment about when to lean on framework abstractions versus when to drop down to the protocol. Solid instincts on concurrency in the JVM: executors, reactive streams, backpressure, connection pooling, and the failure modes that come with each. Thoughtful, transparent use of modern AI development tools (Claude Cod