I’m Andrés, a database developer with over a decade of hands-on experience building query planners and runtime engines. My work revolves around Neo4j and Vitess, and you’ll find most of my contributions right here on GitHub.

• Improving Vitess so it behaves more like MySQL.

• I share my thoughts on my blog
• I’ve also contributed to academic papers—check them out here.

• Grouping & Aggregation Across Shards in Vitess: Brought in the Local Aggregation algorithm (inspired by this paper) to optimize shard-level aggregations across joins. Learn more
• New Query Optimizer for Vitess: Leading the charge on a new optimizer based on the GOO paper, adapted for Vitess’s sharded architecture.
• MySQL Compatibility for Vitess: Helped enhance Vitess so it behaves more like MySQL, which involved overhauls to both the planner and runtime.
• Neo4j’s Cypher Query Planner: Designed and wrote most of the inaugural Cypher planner, applying relational optimization concepts to graph queries.
• Creation of Cypher: Oversaw the specification and standardization of Neo4j’s query language, now the go-to for countless developers. Cypher Spec
• Morsel Runtime in Neo4j: Worked on the early version of Morsel, boosting query performance in Neo4j.
• Compiled Runtime for Neo4j: Part of the original development team, helping Cypher queries run faster by compiling them to bytecode.
• PlanetScale’s Boost Caching System: Designed the planner for a caching approach that transforms the plan tree into a plan DAG, allowing operators to be reused multiple times.

• #3 contributor to Vitess and #5 contributor to Neo4j—both major open-source database systems
• My contributions have helped these projects scale to thousands of users daily, improving performance and reliability in mission-critical deployments.
• Author of influential blog posts and academic papers

If you’re looking for someone with deep expertise in distributed databases or query optimization, I’m always interested in exploring new roles and collaborations.