Senior Software Engineer – Query Optimizer


Seattle, WA, USA Remote

Full time

Nov 12

This job is no longer accepting applications.

Are you interested in working in a dynamic and growing international company with a strong Open Source culture and whose products are used by big Internet and other companies all over the world? MariaDB is the fastest growing Open Source database worldwide, with more than 12 million users. We power applications at companies like, Virgin Mobile and Wikipedia, and we partner with companies like Alibaba and Facebook. The company was founded by the team that founded and built MySQL and enjoys unprecedented technical depth for a startup.

Xpand is the distributed SQL offering of MariaDB and is solving one of the most difficult open problems in the software database industry today: scaling transactional workloads. We’ve built our own distributed relational database from the ground up and integrated with MariaDB. Now we’re looking for smart and motivated folks to join our small team of developers and take this technology to the next level. We work on:

  • C codebase with a custom standard library
  • Database fundamentals: B-trees, logging, and recovery, MVCC
  • A rule-based, cost-based query planner with top-down optimization similar to Cascades Framework
  • An MPP, distributed database with unique query planning challenges that are more complicated (and more interesting) than a single node database


You should be someone with 3+ years of experience with query planner development and:

  • An understanding of table statistics and cardinality estimation
  • Familiarity with the top-down query optimization framework
  • Experience with cost modeling
  • Experience with development of analytics features for SQL

What’s in it for you?

Here are four things that are great about being part of the Xpand team:

  • Our team is small, so you get to own significant projects and contribute in a big way to the product.
  • We have a lot of interesting problems to work on, in a variety of areas.
  • Our customers love us. We help them do things they could never do with their legacy SQL databases.
  • We are passionate about making our software work better and faster

Our customer base is growing, both in number and in size of deployment. Their clusters keep getting bigger and their workloads more varied, so you will see interesting challenges and solutions in solving those.

We provide a very competitive compensation package, 25 days paid annual leave (plus holidays), medical/dental/vision insurance, stock options, 401(k), a massive degree of flexibility and freedom, and more.


This position can be based in Redwood City, CA, Seattle, WA, or Remote (must overlap with PST business hours).

Let’s build a scalable database!

How To Apply

If you are interested in this position, please submit your application along with resume/CV to MariaDB does not sponsor work visas or relocation. MariaDB is an equal opportunity employer.

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