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LeetCode focuses mainly on algorithms, while data science requires skills like SQL, statistics, and working with real data.
Different platforms offer various ways to prepare, from building portfolios to live interview practice.
Practicing with real projects and interview-like problems helps more than just solving coding challenges.
LeetCode is a popular site for coding practice, especially for software engineers. But for data scientists, it often falls short. Most of its problems focus on algorithms and data structures, while data science interviews test skills like SQL, statistics, machine learning, and working with messy real-world data. Several platforms do a better job of preparing candidates for these kinds of roles. Let’s have a look at some of them.
Kaggle is known for its competitions in machine learning, but plays a larger role by making diverse real-world datasets, from housing prices to music playlists, available. Many companies use Kaggle problems to test candidates’ practical thinking. It’s a solid place to build a portfolio, especially for those without work experience.
Also Read: Top 10 Data Scientists to Follow in 2025
DataLemur is a platform that helps people practice real interview questions for data scientists. Most of the questions are about writing SQL queries or solving business-related statistics problems. For example, you might need to calculate click-through rates or check the results of an A/B test. You can do everything online without needing extra software. It’s great for people getting ready for entry-level jobs or product data scientist roles.
DataCamp offers easy-to-follow, interactive courses in Python, R, SQL, and machine learning. The lessons use real examples, like looking at YouTube trends or predicting when customers might leave. You can write and run code right in the course. Daily goals and streaks help keep you motivated. It’s good for beginners and anyone who wants to improve their skills before job interviews.
HackerRank is often used by tech companies to screen candidates. It offers a wide range of coding challenges, but also has sections just for data science, including SQL, statistics, and machine learning. Each task shows the skills being tested, which helps learners focus on areas they need to improve. It’s also one of the few platforms that mimics what a company’s actual test might look like.
Pramp is special because it offers live, practice interviews with other people. You take turns being the interviewer and the interviewee, using set questions. This helps you get better at solving problems quickly and talking clearly during interviews. For data science, you might work on case studies or solve business problems in real time. It’s a good way to practice real interview situations.
The Mode Analytics SQL Tutorial takes a practical learning route for SQL with real datasets like user activity logs and sales data. Activities involve such things as finding top-selling products or computing regional revenue, which fit analytics or data analyst jobs demanding much SQL capability.
Exercism offers language-specific coding practice, such as Python and SQL, with a focus on mentorship. Volunteer mentors critique submitted code and provide individualized feedback, creating a collaborative learning environment. Challenges target single concepts, allowing for foundational skill development. The site is offered for free, rendering it an ideal learning tool for students and job seekers.
InterviewBit integrates coding problems with a curriculum built around databases, system design, and analytics. It includes leaderboards and performance-driven referrals, which can maintain motivation and allow friendly competition. This platform attracts candidates looking for an all-inclusive and goal-based preparation route.
TopCoder, which has historically specialized in algorithm competitions, now offers data science competitions based on real business issues like insurance claims prediction or demand prediction. Regular competition provides financial incentives as well as professional accolades and is therefore appropriate for those with intermediate to advanced levels of experience.
Codewars provides concise, targeted coding challenges called katas for all levels. Data manipulation and logic puzzles are the focus of the platform. Upon completing challenges, users are able to read different solutions, promoting different problem-solving techniques. A supportive community further supplements the learning process by creating the space for interaction and friendship.
Data scientists have many platforms besides LeetCode to help with their work. DataLemur and Mode Analytics focus on SQL and stats practice. Kaggle and DataCamp offer projects and courses. Pramp and Exercism help with interview practice and mentoring. The best platform depends on your job, skills, and how you like to learn. LeetCode is just one option among many.
