This class will be live online (i.e. synchronous).
This course is a part of ProTech. Please review eligibility requirements below before applying.
How to quickly learn and go to work on an existing codebase
Writing new code for a new project is only part of the job. Professional developers more often need to join an existing project, understand unfamiliar systems, diagnose issues, and contribute safely within someone else’s codebase.
The Learning and Testing an Existing Codebase continuing education course helps you build those skills through hands-on exploration of a real multi-service application. You’ll learn a repeatable framework for understanding complex systems, tracing how they work, debugging problems, and making changes with confidence.
You’ll also learn how modern engineers use AI tools like Claude Code to accelerate system exploration-without relying on shortcuts or guesswork.
This course blends real engineering habits with modern AI workflows so you can ramp up faster in today’s development environments.
Is this course for you?
This course may be a great fit if you:
- Know some programming but feel overwhelmed by larger codebases
- Want experience working in an existing application instead of only building from scratch
- Want to better understand how front-end, back-end, database, and infrastructure pieces connect
- Want to improve debugging and troubleshooting skills
- Want to contribute more confidently on a development team
- Want practical experience using AI tools in real engineering workflows- Want to learn how experienced developers quickly understand unfamiliar systems
Whether you’re a recent graduate, self-taught developer, bootcamp alum, or working engineer looking to level up, this course is designed to build real-world confidence. If you’re ready to move beyond tutorials and gain the skills to understand, debug, and contribute to real systems, this course is for you.
What will the course cover?
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System Explorer Framework
The System Explorer Framework is made up of 6 steps by which you can explore, learn and investigate an existing codebase. The steps include: Run, Map, Trace, Model, Debug, Contribute. -
Run: Investigating Systems Step-by-Step
You’ll start by getting the application running locally using Docker. This phase focuses on understanding exactly what the system does from a high level before you look at the code. -
Map: Identifying Components
You will identify the major components, services, and frameworks within the system. This allows you to see how the codebase is organized and how different parts of the tech stack interact. -
Trace: Following User Actions
Learn to follow real user actions as they move through the front-end, back-end, and APIs. You’ll see exactly how data travels through the system and is stored in the database. -
Model: Understanding Behavior
You will build a mental model of data structures, contracts, schemas, and system behavior. This deep dive helps you predict how the system should function under different conditions. -
Debug: Investigating Failures
Gain hands-on experience using logs, tooling, and observation techniques to investigate failures. You’ll learn the logical process of identifying where a system is breaking and why. -
Contribute: Making Safe Changes
Learn how testing, conventions, and existing patterns guide safe code changes. This ensures you can contribute to a project while maintaining the integrity of the existing codebase. -
Modern AI Workflows
You’ll also learn how to use Claude Code through the command line and inside Visual Studio Code, including: Exploring repositories faster, Creating reusable custom skills and context files, Using AI to summarize unfamiliar code, Comparing manual findings to AI-generated finding, Understanding limitations of non-deterministic systems, Verifying AI output like a professional engineer, and Practical LLM basics every developer should know.
How will you learn the material?
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Schedule
Mondays and Wednesdays 9 - 11 AM CT -
Location
This class is live online (i.e. synchronous).
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Dates
May 18 - July 22, 2026
(No class Mon., May 25 due to Memorial Day; that session will be held Tues., May 26) -
Tuition
FREEThis course is a part of ProTech. Please review eligibility requirements below before applying.
What is required?
- Basic programming experience in any language
- Must be 18+ years old
- Personal Computer/Laptop with the following requirements: Modern Windows, macOS, or Linux computer, 16 GB RAM minimum (students with 8 GB RAM on their machines have experienced very poor performance with the work in this class), at least 20 GB of free disk space, reliable high-speed internet, webcam and microphone
- Helpful, but optional: Familiarity with Git & GitHub, Basic command line experience, and Visual Studio Code experience
ProTech Eligibility
- Must reside in Middle Tennessee
- Graduate of NSS, another coding bootcamp, or college/university with tech-related degree AND searching for your first job in tech.
- Tech professional who is unemployed after being laid off from a tech job
Attendance Information
Our policy regarding absences is based on making sure you get the most out of your professional development. Attendance is tracked for this course. Excused absences should be arranged with your instructor before they occur. Due to the short duration of this course we recommend that you not miss multiple days of this course. Absence due to emergencies are always excused as long as the instructor is notified as soon as possible.