See Claude Code in Action

Software Development with Claude Code

Dani Zysman

AI Curriculum Manager @ DataCamp

Where Claude Code Fits

Claude products hierarchy: Web Chat, Desktop App, Terminal CLI

Claude.ai: Chat interface, general tasks
Claude Desktop: App with file access
Claude Code: Terminal-based, built for coding

Get Started

$ curl -fsSL https://claude.ai/install.sh | bash

For more info visit: https://code.claude.com/docs/en/overview

$ cd /path/to/your/project
$ claude

Useful commands:

/clear to clear conversation history
/exit or Ctrl + C to exit the session
/help shows available commands

Navigating Confusing Code

def process_data(records, threshold=0.5):
    result = []
    for r in records:
        if r.get('value') and r['value'] > threshold:
            x = r['value'] * 1.1 if r.get('premium') else r['value']
            result.append({'id': r['id'], 'adjusted': x, 'flag': x > 1})
    return sorted(result, key=lambda d: d['adjusted'], reverse=True)[:10]

Single letter variables
No comments
Packed logic

Claude Explains and Documents

> What does process_data() do?

process_data(): Filter, Adjust & Rank

Filter: Keep records where value > threshold (default: 0.5)
Adjust: Apply 10% boost if premium=True
Transform: Output id, adjusted value, and flag (if adjusted > 1)
Sort: Return top 10 by adjusted descending

> Add a docstring to process_data()

"""Filter records above threshold, apply 10% premium uplift, and return 
the top 10 by adjusted value."""

Spotting a Bug

def add_item(item, item_list=[]):
    item_list.append(item)
    return item_list

Can you spot the issue?

Claude Finds and Fixes the Bug

> Find the bug in add_item() and fix it

Bug found and fixed: The issue was a mutable default argument. 

Using item_list=[] means all calls to add_item() without providing a 
list argument would share the same default list object, 
causing items to accumulate across calls.

def add_item(item, item_list=None):
    if item_list is None:
        item_list = []
    item_list.append(item)
    return item_list

Troubleshooting

Issue	Solution
"Context window exceeded"	Use `/clear` to reset
Rate limits	Wait and retry
Poor results	Keep prompts focused on one task

The Feedback Loop

The development loop: Describe, Generate, Review, Refine

Let's Practice!

Software Development with Claude Code