Senior Staff Software Engineer - Query Execution

Headquarters: Portugal - Remote Be Part of Building the Future Dremio is the unified lakehouse platform for self-service analytics and AI, serving hundreds of global enterprises, including Maersk, Amazon, Regeneron, NetApp, and S&P Global. Customers rely on Dremio for cloud, hybrid, and on-prem lakehouses to power their data mesh, data warehouse migration, data virtualization, and unified data access use cases. Based on open source technologies, including Apache Iceberg and Apache Arrow, Dremio provides an open lakehouse architecture enabling the fastest time to insight and platform flexibility at a fraction of the cost. Learn more at www.dremio.com. About the role Dremio’s Query Execution team builds the runtime responsible for executing analytical queries at scale. The team sits between query planning and table scans, owning the systems that turn query plans into efficient, reliable execution. As a Senior Staff Software Engineer, you’ll work on query operators, expression evaluation, memory management, execution scheduling, runtime planning, and performance optimization. Your work will directly affect query performance, scalability, and reliability across Dremio’s cloud data platform. What you’ll be doing • Build the execution engine: Design, implement, test, and support query operators, expression evaluation, execution scheduling, runtime planning, and resource management. • Improve runtime performance: Optimize vectorized processing, concurrency, parallelism, memory usage, data exchange, and disk spilling. • Diagnose difficult problems: Investigate query correctness and performance issues using query profiles, profiling tools, telemetry, benchmarks, logs, and production data. • Optimize Java and the JVM: Improve CPU utilization, allocation behavior, garbage collection, thread behavior, and other runtime characteristics. • Collaborate across the query engine: Work with Query Planner, Datalake, Product, Support, and field engineering teams on end-to-end query improvements. • Use AI-assisted development tools: Apply AI tools to code comprehension, debugging, test generation, documentation, and incident analysis. • Apply engineering judgment: Validate AI-generated code and recommendations through review, testing, benchmarking, and engineering judgment. • Raise the engineering bar: Participate in design and code reviews, contribute to technical direction, and mentor other engineers. What we’re looking for • Software engineering experience: 5+ years developing production software, preferably in database systems, query execution, distributed systems, or related areas. • Programming skills: Strong Java skills; experience with C++ is a plus. • Computer science fundamentals: Strong foundation in data structures, algorithms, concurrency, multithreaded programming, and asynchronous programming. • Database and distributed systems knowledge: Understanding of database internals, query processing, distributed execution, and performance optimization. • Performance engineering experience: Experience profiling and optimizing CPU, memory, garbage collection, thread behavior, or other runtime characteristics. • Problem-solving ability: Ability to solve ambiguous technical problems and work effectively across team boundaries. • Engineering judgment: Ability to evaluate tradeoffs, validate solutions rigorously, and make sound decisions when working with unfamiliar or AI-assisted implementations. • Communication and ownership: Strong communication skills, a sense of ownership, and a commitment to delivering high-quality software. Bonus points if you have • Query engines: Distributed query engines, database engines, or large-scale data processing systems. • Execution techniques: Vectorized execution, query operators, expressi