Our interview process begins with an initial screening to assess basic qualifications, followed by a technical assessment tailored to the role's requirements.

Candidates then proceed through a series of interviews, including technical, problem-solving, and behavioral rounds, with a focus on skills, adaptability, and cultural alignment.

Final steps involve a meeting with key team members or leadership to ensure a mutual fit and values alignment, providing both the candidate and our team a comprehensive view of potential collaboration.

Question: Given a string, write a function to find the longest substring without repeating characters. The function should return the length of this substring.

Example:

Input: "abcabcbb" Output: 3 (Explanation: The answer is "abc" with the length of 3.)

Constraints:

Assume the input string only contains ASCII characters. Aim for an optimal solution in terms of time complexity.