Learn the patterns.
Solve the interview.

Python and JavaScript courses with 100 original challenges to turn string fundamentals into problem-solving skills.

# Two-pointer palindrome example
# Returns True if the string reads the same forwards and backwards

def is_palindrome(s: str) -> bool:
    left, right = 0, len(s) - 1
    while left < right:
        if s[left] != s[right]:
            return False
        left += 1
        right -= 1
    return True

print(is_palindrome("racecar"))  # True
print(is_palindrome("python"))   # False

Two languages. 30 practical lessons.

Go from core string concepts to scalable patterns to interview-ready problem solving.

1

String foundations

Python + JavaScript

Understand each language’s string model and essential operations.

String model · Indexing and slicing · Normalization · Efficient construction

2

Patterns that scale

Reusable interview patterns

Learn reusable patterns to solve problems efficiently.

Frequency maps · Two pointers · Sliding windows · Parsing and validation

3

Interview practice

Advanced Python topics

Apply what you’ve learned with progressively harder challenges.

Unicode · Structured parsing · Tries · Dynamic programming

Choose your starting point

Simple, flexible options for your goals.

Course

$79

30 written lessons across Python and JavaScript

  • In-depth, easy to follow lessons
  • Code examples and explanations
  • One-time purchase
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Practice pack

$39

100 original challenges

  • 100 problems in both languages
  • Increasing difficulty
  • Detailed solutions and explanations
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Complete bundle

$99

Course + practice pack

  • All 30 lessons
  • All 100 original challenges
  • One connected learning experience
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