Senior Software Engineer, Query
Confirmed on the employer's own hiring board on Oct 22, 2026. First seen by Alion on Oct 21, 2026. MongoDB scores B on the Alion truth index.
The MongoDB Query Testing Tools Team is hiring Software Engineers who want to join us in building a state-of-the-art distributed query system. Our Team builds tooling that allows us to ship Query Engine features with high confidence in both correctness and performance, making it a great fit if you like seeing your work protect real customers at scale. The team develops advanced testing frameworks (end-to-end testing, fuzzing, property-based testing) as well as performance measurement tools, including high-volume workload generation tools.
The team is part of the Query organization which is responsible for the MongoDB Query Language and the lifecycle of each query, from parsing to optimization to plan selection; our engineers work on maintaining and improving our optimization and execution frameworks and building new query language features to help power our customers' critical workloads. Throughout all our work, our highest priority is always ensuring that customer queries are answered correctly. The successful applicant will be responsible for helping us to maintain the highest standards of quality through rigorous development, testing and automation strategies.
This role can be based out of our Dublin office, or remotely in Ireland.
Candidate Profile
- 5+ years of experience in software development and/or performance engineering
- Fluency in Python, Javascript or Typescript
- Enjoys chasing down difficult problems in a distributed environment
- Able to make complex concepts easy to grasp in written and spoken English
- Able to decompose and solve complex problems and can rapidly iterate by validating new hypotheses and rethinking current assumptions
- Demonstrating hands-on experience working with relational or NoSQL databases is a plus
- B.Sc. in Computer Science or related field, or equivalent practical experience. Advanced degrees of experience in database query engines is a plus
- Experience in developing automation test frameworks is a plus
- Experience in query processing engine testing is a strong plus
- Experience in developing performance test plans and monitoring frameworks is a strong plus
- Background in database query engines or compilers is a strong plus
Position Expectations
- Design, develop, and maintain automated testing frameworks, Performance automated tests and internal tooling for the MongoDB query engine
- Collaborate closely with peers to understand new features and functionalities, ensuring testability, test frameworks, tooling and coverage for automating tests of both happy-path and edge-case scenarios
- Provide feedback in code reviews, focusing on the robustness and reliability of code changes
Success Measures
- Within three months, you have gained an understanding of MongoDB's MQL syntax and its semantics, as well as the behavior of our unique query engine. You have contributed to several code bases on Mongodb engine internal tooling
- By six months, you have established yourself as a key owner of automated test frameworks, and demonstrated improvements in test efficiency and coverage
- After twelve months, you are instrumental in ensuring quality of major new features, setting an example for new team members in best practices for correctness and performance test automation and internal tooling
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 AI-native startups and approximately 75% of the Fortune 100, 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: 3273588903