7 Steps to Successfully Onboard to a New Codebase

Joining a new team often means diving headfirst into a complex codebase. Whether you're at a startup or a Fortune 500 company, quickly understanding the code is essential to becoming productive and making meaningful contributions. This guide outlines actionable steps to streamline the onboarding process, inspired by my experience at Lockheed Martin Space. By following these steps, I was able to submit a fully tested merge request within my first week—a testament to the power of a structured and well-supported onboarding process.

Table of Contents

• 1. Familiarize Yourself with the Project Overview
  • Key Steps
• 2. Understand the Architecture
  • Key Areas to Focus On
• 3. Set Up the Development Environment
  • Key Steps
• 4. Start with Small Tasks
• 5. Leverage Documentation and Team Knowledge
• 6. Use Debugging to Learn
• 7. Build Relationships with Your Team
• Bonus Tip: Take Notes and Improve Documentation
• Conclusion

1. Familiarize Yourself with the Project Overview

Start by understanding the big picture. This will help you connect your work to broader goals:

Key Steps

• Understand the Application’s Purpose: Learn what the application does through user guides, demos, or product documentation.
• Know the Users: Identify the target audience and their challenges.
• Explore the Problem Space: Understand the specific issues the software is solving.

At Lockheed Martin Space, I benefited from a 30-minute pre-recorded video explaining the software’s purpose, goals, and high-level architecture. This resource clarified:

• The strategic vision of the software.
• The major components and how they interact.
• The use cases it addresses.

Having this high-level understanding early on made it much easier to contribute effectively.

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2. Understand the Architecture

Once you’ve familiarized yourself with the big picture, it’s time to dive deeper into the system’s architecture. Understanding how the software is structured and how its components interact is essential for making meaningful contributions.

Key Areas to Focus On

The following are areas, I found, are crucial to understanding the architecture:

1. Core Components:

• Identify the primary modules, layers, or services. Examples:
• Front-end, back-end, database, and middleware layers.
• Microservices and their individual responsibilities.
• Understand the role of each component in the overall system.

2. Data Flow:

• Map out how data moves through the system.
• Is it RESTful, event-driven, or message-based?
• What protocols (e.g., HTTP, WebSocket) or patterns (e.g., CQRS, Pub/Sub) are used?
• Look for high-level diagrams showing the flow of requests, responses, and database interactions.

3. External Dependencies:

• Identify third-party services, APIs, or libraries the software depends on.
• Understand how these external systems integrate with the application.

4. Deployment Architecture:

• Review how the application is deployed: is it containerized with tools like Docker, orchestrated with Kubernetes, or deployed on a cloud platform?
• Learn about staging, testing, and production environments.

At Lockheed Martin, the onboarding process included a 30-minute pre-recorded video that provided a 40,000 ft view of the system architecture. It clarified:

• The high-level architecture and interactions between major components.
• Integration points with external systems and dependencies.
• The design philosophy behind architectural decisions.

Why does this step matter? Understanding the architecture helps you:

• Navigate the codebase efficiently by focusing on key areas.
• Spot potential risks or issues based on how components interact.
• Contribute meaningfully to discussions about design or refactoring.

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3. Set Up the Development Environment

Getting the environment running is one of the first challenges you’ll face.

Key Steps

1. Clone the Repository:

• Confirm permissions, explore the code structure, and note branch conventions.

2. Install Dependencies:

• Use tools like npm, yarn, or maven per the setup guide.

3. Run the Application:

• Use scripts (npm run dev, docker-compose up) to confirm everything works.

If you encounter issues during setup:

• Record errors and solutions to help yourself and future developers.
• Share insights with the team to improve documentation.

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4. Start with Small Tasks

Tackle manageable tasks to build confidence and context:

• Beginner-Friendly Tickets: Fix minor bugs or enhance documentation.
• Write Tests: Understand existing functionality and edge cases.
• Refactor Small Areas: Improve specific sections with guidance.

Working with your team's product owner or tech lead to identify small, manageable tasks can help you gain momentum and build confidence. At Lockheed Martin, I started with a small bug fix that required me to understand the codebase, write tests, and submit a pull request. This task helped me:

• Understand the code structure and conventions.
• Learn the testing framework and code review process.
• Collaborate with team members to resolve issues.

By starting small, I was able to contribute meaningfully and build a solid foundation for future larger tasks. However, not every task will be as straightforward. When you encounter challenges:

• Ask for Help: Reach out to your team for guidance. They’ve been in your shoes before. Don't let your ego get in the way of asking for help.
• Pair Programming: Collaborate with a team member to tackle complex tasks together.
• Break Down the Problem: Divide complex tasks into smaller, manageable subtasks.

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5. Leverage Documentation and Team Knowledge

Maximize available resources to accelerate learning:

• Project Docs: Explore internal guides or wikis.
• Code Comments: Study inline documentation for insights.
• Ask Questions: Reach out to your team or mentor for clarification.

At Lockheed Martin, the combination of onboarding documentation and a supportive team environment significantly shortened the learning curve. Asking targeted questions about workflows and processes helped me navigate challenges effectively.

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6. Use Debugging to Learn

Debugging isn’t just for fixing bugs—it’s an excellent way to explore the codebase:

• Set Breakpoints: Step through code execution to understand data flow.
• Log Outputs: Insert logs to visualize inputs and outputs.
• Run Tests: Examine test cases to understand expected behaviors.

Given the nature of the work at Lockheed Martin, strict security protocols restricted tool usage. For example:

• Tools like IntelliJ IDEA were prohibited due to reliance on cloud features.
• Locally-hosted IDEs like Eclipse or secure versions of Visual Studio Code were used instead.

Despite these constraints, debugging remained a valuable tool for understanding the system. Working within these constraints also strengthened my ability to adapt and deliver quality code with minimal dependencies.

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7. Build Relationships with Your Team

Your team is your greatest resource. Build strong connections by:

• Pair Programming: Collaborate to learn patterns and workflows.
• Code Reviews: Volunteer to review small pull requests to gain context.
• Daily Standups: Share progress and ask for guidance.

At Lockheed Martin, each new hire is paired with an onboarding buddy—an experienced developer tasked with guiding them through the codebase and workflows. This mentorship accelerates onboarding, helping new developers contribute quickly while fostering collaboration and trust.

Why does the onboarding buddy system works?

• Guided Learning: A buddy provides context and answers questions.
• Structured Onboarding: They help you navigate the codebase and workflows efficiently.
• Accelerated Contributions: By having a mentor, you can quickly overcome hurdles and focus on delivering value.

Note: While some might view assigning a buddy as a distraction for experienced developers, in the long run, it pays off. A buddy reduces ramp-up time for new hires, saves the team effort in answering repeat questions, and fosters a collaborative, mentoring culture.

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Bonus Tip: Take Notes and Improve Documentation

Document what you learn—commands, workflows, and solutions. Share your insights with the team to improve onboarding materials for future hires.

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Conclusion

Onboarding to a new codebase is an opportunity to grow as a developer. By following these steps, you can build confidence, contribute effectively, and leave a positive impression on your team. Every codebase has its quirks, but patience, persistence, and collaboration are key to mastering them.