Join Erika, Bethany, Jonathan, and Brittany for a deep dive into one of every developer's most common challenges: learning a new codebase. Based on Brittany's popular GitHub blog post, this episode shares battle-tested strategies for getting up to speed quickly—whether you're joining a new team, switching projects, or contributing to open source.

Working on large-scale systems at GitHub has taught these engineers that you'll never understand everything, and that's okay. The key is knowing where to start and how to build knowledge efficiently while staying productive.

Practical strategies discussed:

Starting with a single issue to avoid overwhelm
Creating personal documentation as you learn
Using pair programming to accelerate onboarding
Leveraging GitHub Copilot for code explanation and documentation
Reading telemetry and Sentry alerts to understand system behavior
Using debuggers to trace code execution paths
Setting up 1:1s with engineers, PMs, and designers for domain knowledge
Finding good first issues in large codebases
Generating entity relationship diagrams from database schemas

Key mindset shifts:

Getting comfortable with not knowing everything at scale
Understanding abstraction boundaries through hands-on work
Distinguishing between lack of experience vs. understanding
Recognizing your contribution's place in the larger system

Spicy hot takes segment: The hosts share their biggest code base pet peeves, including outdated README files that don't work, stale TODO comments from years ago, unhelpful PR templates with required fields, and distributed systems that won't run locally.

Whether you're onboarding to a new team, exploring an unfamiliar microservice, or diving into an open source project, this episode offers actionable advice for confident, efficient code base learning.

Links

https://github.blog/developer-skills/application-development/how-github-engineers-learn-new-codebases/

Hosts

Bethany Janos: https://github.com/bethanyj28
Brittany Ellich: https://brittanyellich.com
Eggyhead: https://github.com/eggyhead
Jonathan Tamsut: https://jtamsut.substack.com/

Learning a New Codebase: Strategies for Software Engineers | Onboarding Tips

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Learning a New Codebase: Strategies for Software Engineers | Onboarding Tips