Senior Software Engineer, Query Execution
Confirmed on the employer's own hiring board on Nov 5, 2026. First seen by Alion on Jul 14, 2026. MongoDB scores B on the Alion truth index.
The MongoDB Query Execution Team is hiring software engineers who want to join us in developing a high performing, reliable and modular distributed query system. Our engineers work on implementing and maintaining execution algorithms, building new query language features, tuning database performance, and more to power our customers' critical workloads.
This role can be based out of our Dublin office or remotely in Ireland. Relocation can be supported.
Position Expectations
- Understand and improve current functionality of the MongoDB query engine
- Contribute high quality C++ code and give and solicit feedback in code reviews
- Identify, design, implement, test, and support new features related to query performance and robustness, query language enhancements, diagnostics for query performance problems, and integration with other products and tools
- Work constructively with peers to deliver excellent technical solutions
Candidate Profile
- 5+ years of experience in systems programming
- Experience in databases and/or data management systems is a huge plus, but not a requirement
- Hands-on experience building industrial-strength software
- Solid computer science fundamentals, with strong competencies in data structures, algorithms, and software design/architecture
- Experience with large code bases, preferably in C++, C, Rust or a similar compiled language
- B.Sc in Computer Science or similar field, or equivalent practical experience
- Interest in the theory and practice of database query engines. Hands-on experience or M.Sc./Ph.D in the domain is a plus
Success Measures
- In three months you’ll have contributed to the development of a project slated for the next major version, as well as fixed a few bugs in a minor version of our latest stable release series
- In six months, you’ll have taken on code review responsibilities and are independently delivering complex functionality and squashing bugs independently
- In twelve months, you’re leading the development of a new major feature and are helping to mentor new engineers on the team
About MongoDB
MongoDB is built for change, empowering our customers and our people to innovate at the speed of the market. We have redefined the data platform for the AI era, enabling builders to create, transform, and disrupt industries with software. MongoDB’s unified data platform, the most widely available, globally distributed data platform on the market, helps organizations modernize legacy workloads, embrace innovation, and unleash AI. Our cloud-native platform, MongoDB Atlas, is the only globally distributed, multi-cloud data platform and is available across AWS, Google Cloud, and Microsoft Azure.
With offices worldwide and over 67,000 customers, including 75% of the Fortune 100 and AI-native startups, relying on MongoDB for their most important applications, we’re powering the next era of software.
Our compass at MongoDB is our Leadership Commitment, guiding how and why we make decisions, show up for each other, and win. It’s what makes us MongoDB.
To drive the personal growth and business impact of our employees, we’re committed to developing a supportive and enriching culture for everyone. From employee affinity groups, to fertility assistance and a generous parental leave policy, we value our employees’ wellbeing and want to support them along every step of their professional and personal journeys. Learn more about what it’s like to work at MongoDB, and help us make an impact on the world!
MongoDB is committed to providing any necessary accommodations for individuals with disabilities within our application and interview process. To request an accommodation due to a disability, please inform your recruiter.
MongoDB is an equal opportunities employer.
Req ID: 2273491237