Foundations
Develops expertise in foundational systems, such as deployments, pipelines, databases and machine learning
Level 1
Works effectively within established structures, following current best practices
Writes thorough postmortems for service outages
Makes simple configuration changes to services
Performs backfills safely and effectively, without causing pages
E.g. Made safe and effective Ansible changes
E.g. Implemented new ETL pipelines based on existing ones
E.g. Resolved out of disk errors independently
Level 2
Develops new instances of existing architecture, or minor improvements to existing architecture
Made minor version upgrades to technologies
Builds machine learning jobs within the ML framework
Triages service issues correctly and independently
E.g. Upgraded NodeJS from 8.0 to 8.1.1
E.g. Built custom packages for RPMs
E.g. Improved ETL efficiency by improving Dynamo to S3 loading
Level 3
Designs standalone systems of moderate complexity, or major new features in existing systems
Acts as primary maintainer for existing critical systems
Designs moderately complex systems
Makes major version upgrades to libraries
E.g. Designed Ansible configuration management
E.g. Built Medium's realtime stats pipeline
E.g. Designed flexible framework for writing machine learning jobs
Level 4
Builds complex, reusable architectures that pioneer best practices for other engineers, or multi-system services
Designs complex projects that encompass multiple systems and technologies
Demonstrates deep knowledge of foundational systems
Introduces new databases and technologies to meet underserved needs
E.g. Designed and built BBFD
E.g. Designed AWS configuration management
E.g. Introduced Kinesis and pioneered streaming events pipeline
Level 5
Is an industry-leading expert in foundational engineering or sets strategic foundational direction for an eng team
Designs transformational projects in service of long-term goals
Defines the strategic vision for foundational work and supporting technologies
Invents industry-leading techniques to solve complex problems
E.g. Invented a novel ML technique that advanced the state of the art
E.g. Defined and developed Medium's continuous delivery strategy
E.g. Developed and implemented HA strategy