Engineering's Ability: Data Modeling / Management

Develops expertise in database administration, security, and strategy in our stack of PostgreSQL, Redshift, ElasticSearch, Redis, Memcached, and whatever comes next.

Eventually we will assess Milestones across three axes:

• Data Modeling
  • Taking into account maintainability, performance of both reads and writes, extensibility, and analysis needs
• Data Operations
  • Taking into account security, production data manipulation, and optimization
• Data Usage
  • Knowing when data belongs in Redis and not PostGres, thinking about access patterns, knowing when to cache, knowing when to process via background job, and even impacting UI/UX decisions (this get close to Code Authoring, but focuses on data)

I have observed this person showing a consistent, comfortable, continuous, and clear positive impact to a squad when wielding this ability, and therefore I would put them in situations where they can employ this ability with only a small amount of guidance

• Writes simple queries (either directly or through library code) that return and update data effectively utilizing joins and selects.
• Adds columns to existing database tables or adds new tables using existing schema conventions.

I have observed this person showing a consistent, comfortable, continuous, and clear positive impact to a squad when wielding this ability, and therefore I would put them in situations where they can employ this ability, with no assistance as well as being a trusted active or passive mentor to others

• Performs migrations and other database changes with zero impact to application performance or uptime.
• Identifies and addresses missing indexes and constraints to keep our data consistent and easy to query.
• Has a strong understanding of how our database tools work and shares that knowledge to improve others’ database use in code reviews (e.g. seeks and shares insights about query performance and optimization via EXPLAIN results).
• Models entire domains using single table inheritance, polymorphism, and other advanced modeling techniques with assistance from others
• Retrieves data in the most performant and efficient way by minimizing n+1 queries
• Uses transactions (such as Postgres’ BEGIN/COMMIT or Redis’ MULTI/EXEC) to preserve atomicity when appropriate.
• Models data leveraging the most appropriate data types and relationships between existing data

I have observed this person showing a consistent, comfortable, continuous, and clear positive impact to multiple squads when wielding this ability, and therefore I would put them in situations where they can employ this ability as well as being considered an expert within this discipline

• Identifies queries that consistently underperform and updates them to reduce strain and response times in the database.
• Identifies and ushers adoption of systems that detect and proactively alert us to potential database issues (like strong_migrations)
• Models entire domains using single table inheritance, polymorphism, and other advanced modeling techniques with little or no assistance
• Retrieves data utilizing recursion and common table expressions (views, stored procs)

I have observed this person showing a consistent, comfortable, continuous, and clear positive impact to a squad when wielding this ability, and therefore I would put them in situations where they can not only employ this ability but where they set the tone for this at the company level

• Spearheads monumental database changes with minimal negative impact (like customer-level data segregation)
• Assists team members with complex data issues

I have observed this person showing a consistent, comfortable, continuous, and clear positive impact to not just internal teams but the community/industry in general when wielding this ability, and they are recognized by the community/industry as an expert