New Codebase Onboarding Strategies for Efficiently Learning a New Codebase

Harrison Strowd
Harrison Strowd

Jumping into a new codebase can be daunting. Whether you're joining a new team or tackling an unfamiliar project, getting up to speed efficiently is crucial. As a consultant, I've gotten practice joining well-established organizations and have developed some guidelines that help accelerate the learning curve on their systems. While I tend to progress through these steps in the order presented, feel free to adapt the approach based on your needs.


Jumping into a new codebase can be daunting. Getting up to speed efficiently is crucial.


Use the README

The README is generally the best place to start. It provides an overview of the application and essential context. Even if you don't immediately act on the information, it lays a solid foundation for understanding the system.

Here's how to make the most of it:

Build a Mental Model

Understanding the system as a whole will provide context for your work. Seek answers to key questions such as:

If high-level architecture documentation exists, review it. If not, consider creating the following diagrams to solidify your understanding:

While these diagrams will benefit the team as a whole, the real value lies in the deep understanding you gain by creating them.

Not sure where to start in crafting these diagrams? Reach out and we can provide some examples from our personal/internal projects or guidance for your specific case.


While these diagrams will benefit the team as a whole, the real value lies in the deep understanding you gain by creating them.


Learn to Test the Application

Hands-on experience is invaluable when familiarizing yourself with a new codebase. Start testing the application by:

This investment of time will pay off as you begin making functional changes with confidence.


This investment of time will pay off as you begin making functional changes with confidence.


Extend Engineering Utilities

Building and improving engineering utilities will benefit both you and your teammates while accelerating your onboarding. Depending on existing team tools, consider:

These initiatives can be self-directed, giving you hands-on experience while providing immediate value to your team.

Find an Area to Go Deep

Once you have a solid grasp of the system, it's time to specialize. Work with your manager or teammates to identify a moderately complex feature or area with changes or improvements to be made.

Developing expertise in a specific area allows you to contribute in more impactful ways beyond incremental code changes. As your knowledge grows, you'll also be in a better position to provide insight into the application's architecture and influence the team's technical direction.


Developing expertise in a specific area allows you to contribute in more impactful ways beyond incremental code changes.


What else?

By following these steps, you'll gain a comprehensive understanding of the codebase, contribute meaningful improvements, and set yourself up for long-term success within your team.

Do you have other strategies you follow when getting up to speed on a new codebase? If so, we'd love to hear about them. Drop us a note below, and thanks for reading!

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