Here are 15 popular websites for coding challenges and competitions:
LeetCode – Offers coding challenges to prepare for technical interviews.
HackerRank – Provides coding challenges, competitions, and interview preparation.
Codeforces – Features competitive programming contests and challenges.
CodeChef – Offers coding challenges and competitive programming contests.
TopCoder – A platform for competitive programming and design challenges.
AtCoder – Provides programming contests and challenges for all levels.
Exercism – Offers coding exercises to improve coding skills.
SPOJ (Sphere Online Judge) – Hosts programming challenges and contests.
Project Euler – Focuses on mathematical problems that can be solved through coding.
Coderbyte – Provides coding challenges, interview prep, and resources.
Kaggle – Known for data science challenges, competitions, and datasets.
Google Code Jam – An annual competitive programming competition hosted by Google.
Facebook Hacker Cup – Facebook’s global programming competition.
Kick Start – Google’s online coding competition for programmers of all levels.
InterviewBit – Offers coding challenges and interview preparation.
These websites provide a wide range of coding problems, from beginner to expert levels, and often host contests for programmers to showcase their skills.