Staff Software Engineer, Query Execution

MongoDB's mission is to empower innovators to create, transform, and disrupt industries by unleashing the power of software and data. We enable organizations of all sizes to easily build, scale, and run modern applications by helping them modernize legacy workloads, embrace innovation, and unleash AI. Our industry-leading developer data platform, MongoDB Atlas, is the only globally distributed, multi-cloud database and is available in more than 115 regions across AWS, Google Cloud, and Microsoft Azure. Atlas allows customers to build and run applications anywhere—on premises, or across cloud providers. With offices worldwide and over 175,000 new developers signing up to use MongoDB every month, leading organizations trust MongoDB to build next-generation, AI-powered applications.

Join the MongoDB Server Query Execution team as a Staff Software Engineer and help build a world-class distributed open-source database. You will contribute to the core query execution engine that powers all queries, develop the physical operators for data retrieval and manipulation, and improve runtime for analytical and transactional workloads. You will also own critical components like the Change Streams infrastructure and support the query execution needs of Atlas Streams, Atlas Search, Vector Search, and mongosync.

This role is based remotely in Ireland, with options for office-based work in European hubs (Dublin and Barcelona) and remote work in several countries (including the Netherlands, Great Britain, Italy, Germany, Spain, and France). The team is globally distributed across Europe and North America, and you will regularly collaborate with colleagues across different time zones.

• Define the 12-month roadmap for Query Execution by researching state-of-the-art systems and industry trends to provide technical vision and direction
• Take direct responsibility for delivering long-term goals (6–18 months) to innovate in high-performance query execution, coordinating initiative-level strategy, and writing well-tested production-ready C++ code
• Advise management on key architectural decisions and collaborate with stakeholders across the company on large initiatives
• Mentor and coach team members, lead by example, and contribute to knowledge sharing and interviewing to build a strong talent bench

• 10+ years of experience in data management systems
• Experience building production-level code with a large user base, robust design, and rigorous code quality
• Degree in Computer Science or a related field, or equivalent practical experience, with strong competencies in data structures, algorithms, and software design/architecture
• Experience with large code bases written in C++ or another systems programming language; ability to trace defects, estimate work complexity, and design evolution and integration strategies
• Passion for the theory and practice of database query engines, with hands-on or academic experience in the database domain

• Play a key role in defining the 12-month roadmap for Query Execution and provide technical vision by researching state-of-the-art systems and industry trends
• Take responsibility for delivering on long-term goals to innovate in high-performance query execution, coordinating initiative-level strategy, and delivering production-ready C++ code
• Advise management on architectural decisions and collaborate with stakeholders on large initiatives
• Mentor and grow team members through coaching, knowledge sharing, and leading by example

• In three months, contribute to a project for the next major version and fix bugs in a minor version of the current release; learn MongoDB project lifecycle and goals
• In six months, participate in code reviews and contribute to design discussions for new features; present a relevant paper or system architecture
• In twelve months, contribute to the long-term technical roadmap of the MongoDB Query team based on your experience

We're committed to a supportive culture for everyone. MongoDB offers resources for personal growth and wellbeing, including employee affinity groups, fertility assistance, and generous parental leave. MongoDB provides accommodations for applicants with disabilities in our application and interview process. To request an accommodation due to a disability, please inform your recruiter. MongoDB is an equal opportunities employer.