Learns to write correct Go code, following guidance and training materials

Fixes simple bugs or issues

Proactive in asking questions, explains what they have tried so far and why that hasn’t worked

Asks questions and actions feedback from PRs and other engineers

Uses git to manage the development workflow effectively E.g. Checkout, Push, Pull, Branch, Diff, Merge, Stash, Rebase, etc.

Designs simple database tables

Implements asynchronous messaging between services

Deploys services to staging and production

Handles simple error cases in RPC handlers and message consumers

Fixes bugs involving a number of services and can investigate production issues

Uses appropriate algorithms and data structures to solve problems

Implements simple RPC handlers

E.g. Basic CRUD handlers, Internal/external API proxies

Writes correct Go code following accepted best practices

Follows our Coding Conventions & Best Practices, uses language-level primitives correctly

Uses appropriate design patterns

Designs new schemas comprising multiple tables

Implements complex asynchronous messaging flows

Co-ordinates complex deployments and database migrations

Implements distributed systems consisting of multiple interacting services

Produces technical designs that include a consideration of scalability

Handles complex error cases in RPC handlers and message consumers

Debugs production issues

Considers metrics when building a new system

Writes idiomatic Go code

E.g. Follows the guidelines in Effective Go, avoids using patterns that are idiomatic in other languages

Mitigates race conditions and partial failure states in distributed systems

E.g. Uses locking where appropriate, writes code that is “self-healing” when dealing with distributed failure (e.g. data needs to be written in two or more services)

Implements complex RPC handlers

E.g. Implements complex business logic, orchestrates multi-stage processes, deals with idempotency or distributed data sources

Proactively considers security implications of their work

Appropriately ties down internal access to resources they're working with (e.g. RPC blacklisting, BigQuery permissions)

Evaluates security risks when contributing to proposals

Highlights potential security issues when raising and reviewing pull requests - e.g. adding rate limiting in an API, or leaving a code comment to explain why we choose not to

"There's a risk here of X, Y but given Z, I think this is OK"

Loops in Security when their squad is unsure about something by posting in #security-requests

Writes code that serves as a definitive example for new engineers

Leads the refactoring (de-cruftification) of complex systems

Debugs complex production issues at speed

Identifies and fixes security vulnerabilities

Identifies and fixes performance bottlenecks in individual services

Explains all aspects of the platform to new engineers

Includes actionable dashboarding as part of a new system

Implements services or libraries that require a deep level of domain knowledge

E.g. Mastercard message parsing, Credit decisioning, CASS scheduling, Google Pay

Makes contributions to library code or core services

E.g. Bug fixes, small improvements; things that don’t result in a major change in the public API

Builds systems that scale reliably without intervention

E.g. Services can withstand a year’s worth of growth in load/user base without needing first aid

Builds systems that serve as definitive examples for new engineers

Makes major contributions to library code or core services

Contributes to external technologies or libraries that we depend on

Develops clear technical solutions from ambiguous requirements

Uncovers and fixes tricky bugs that have previously evaded detection

Implements security improvements that impact multiple services

Implements performance improvements that impact multiple services

Demonstrates a deep level of knowledge in a specific area

Serves as a technical authority on a technology or an area of the codebase

Creates dashboards that broadly impact all engineers

Produces clear technical designs for large complex projects

E.g. Outbound and Inbound MasterCard clearing proposals

Makes major contributions to technologies and libraries that we depend on

Makes improvements to the stability, performance or security of the entire platform

Serves as a technical authority in the wider engineering community