If you are targeting a technical position in a company like Facebook, Google, or Amazon, you’ll likely be tasked with a system design interview. These interviews can be tough to crack if you haven’t learned how to answer system design questions, but the right prep can spell the difference between passing and failing your interview. 

Consider hiring an expert mock interviewer to practice with. To get you started, we’ve put together a curated list of the best system design mock interview platforms you can explore. 

You'll learn which platforms offer the best value, in terms of pricing and the quality of their mock interview coaching, and how they may fit into your unique needs and budget.

Here’s an overview of everything we cover:

1. Why are mock interviews important?
2. Best sites for system design mock interviews
3. Best sites for solo system design practice

Book a one-on-one system design mock interview with expert coaches.

1. Why are system design mock interviews important? ↑

Mock interviews are a crucial part of preparing for a system design interview with a top tech or FAANG company. 

A good mock interview should simulate the conditions of a real interview, especially when done with a mock interview coach who has experience interviewing candidates for system design questions. This helps you:

Overall, practicing with mock interviews can give you a higher chance of acing your real system design interview.

So, where do you even start? Usually, you can split your prep into two stages:

1. Solo practice: Answering system design questions on your own until you’re able to clearly explain relevant concepts and show your thought process.
2. Mock interviews: Simulating real interviews with another engineer or expert coach, so you can practice explaining your approach and managing the stress of a live interview.

Although practicing on your own is useful for researching what questions to expect and how to structure your answers, it’s equally important to learn how to share your thought process clearly and confidently with another person. 

System design interviews don’t just test your technical knowledge. They test how well you can think out loud, respond to challenges, and justify trade-offs. Interviewers now expect not just solid fundamentals, but the ability to communicate complex ideas clearly, explore trade-offs, and remain calm under pressure. 

Mock interviews are the fastest way to develop these skills. Below, we cover the best system design mock interview platforms for both expert-led mocks and solo practice.

2. Best sites for system design mock interviews ↑

System design interviews are high-pressure and unpredictable, especially when you’re applying for a top tech company. 

The best way to get comfortable with them is to practice with mock interviews, ideally with an expert who can guide you through system design questions and offer actionable insights.

Based on our research, here are our top recommendations for system design mock interview platforms:

#IGotAnOffer’s system design mock interview coaching (best value overall / best selection of coaches)

Okay, we may be biased here, but a 4.95 average star rating from over 19k reviews is hard to ignore.

When you're aiming for FAANG, feedback from someone who's been on the hiring side can make all the difference. And that’s one of the reasons IGotAnOffer stands out. Every coach on the platform has worked at top tech companies like Google, Meta, Amazon, and more—and all of them have conducted interviews there as part of their role. 

When booking a mock interview, you can search by company and find a mock interview coach who has run system design interviews at the company you’re trying to get into.

You can also specify exactly what you want to focus on, whether it’s answering a system design question with a defined framework, how to communicate your design thought process, how to talk through trade-offs and scalability considerations, etc. 

IGotAnOffer is transparent and reliable, too. You can see coach credentials, hourly availability, and book your online session in a couple of clicks on their profile, for as little as $100—something you often can’t do on rival platforms.

To book a mock interview session, you’ll first need to buy credits. Each credit starts at $50. Mock interview coaching costs 2, 3, 4, or 5 credits per 1-hour coaching session. And if you’re not satisfied, you get a full refund.

#Pramp (best free system design mock interviews)

Pramp is a free peer-to-peer mock interview platform now hosted on Exponent. It lets you pair with other users for live interview practice in tech roles like software engineering, product management, data science, etc. 

It’s a great way to get real-time practice under interview conditions without spending a dime, especially if you have plenty of prep time left before your interview.

Many candidates start off doing free mock interviews here, and then move on to paid interview coaching to get to the next level.  Pramp great site to use if you have plenty of prep time left before your interview.

You can check out our comprehensive review on Pramp for more details on pricing and services. 

#Codemia (best AI-powered system design mock interviews)

Some people like to have their mock interviews with AI. Codemia is one of the few platforms offering system design mock interviews with an AI interviewer.

Codemia’s AI walks you through open-ended system design prompts, lets you talk through your approach, and then provides feedback. 

Of course, it won’t be able to give you the same depth of feedback as a real human expert, but it’s useful if you just want quick, low-pressure practice. 

#DesignGurus (best for advanced system design practice)

DesignGurus is an online platform providing courses and interview preparation for software engineers, specializing in system design and coding interviews.

DesignGurus helps you prepare for system design interviews by focusing on large, real-world systems. Instead of just giving you the right answer, it explains the reasoning and tradeoffs behind each solution. The platform features complex, in-depth problems that simulate real interview scenarios.

It’s designed for those who have already covered the basics and want something more advanced for their interview preparation.

It’s not the cheapest option and, unlike IGotAnOffer, you can’t filter for interviewers who’ve worked at your target company at the same basic price. But with its reputation for advanced system design practice, it’s a platform worth being aware of if you don’t mind the price.

3. Best sites for solo system design practice ↑

Before you jump into live mock interviews, you may want to warm up by practicing on your own first. 

Solo practice for system design interviews is where you build your foundation: learn common system design patterns, walk through past interview questions, and get used to thinking through big problems from start to finish.

Practicing solo lets you move at your own pace, pause when you need to, and really understand the ‘why’ behind each design choice without the pressure of explaining it to someone else just yet.

It’s also a great way to build up a mental library of real-world systems you can draw from later in interviews.

Here are a few solid places to start for solo system design interview practice:

#System Design Primer, GitHub (best free starting point)

This system design primer on GitHub is probably the most recommended starting resource among engineers looking to brush up on system design concepts. 

It’s community-built and has been starred hundreds of thousands of times, so you know it’s widely used. It goes over the core concepts of system design interviews and provides tons of links for additional reading on relevant concepts, like caching, load balancing, consistency models, etc.

That said, it can be overwhelming to go through the entire database. There’s no built-in structure or timeline, so it’s best if you already have a rough plan for what you want to cover.

#ByteByteGo (best for visual learners)

ByteByteGo is best for solo entry-level interview prep, as it makes difficult concepts seem visually easy to understand and offers a less intimidating approach. Instead of dumping theory, it uses visuals and case studies to show how real systems are built.

It’s great for building mental models and “seeing the big picture,” though some engineers say it doesn’t go deep enough on edge cases if you’re aiming for very senior-level interviews.

#Educative’s Grokking the System Design Interview course (best for structured learning)

Educative’s Grokking the System Design Interview course is one of the most well-known system design courses online among software engineers. 

It walks you through common design patterns and gives you a framework to approach any question. It also guides you through common patterns like designing a URL shortener or a news feed, which could be reassuring if you’re starting your prep from scratch.

However, some users report that it can feel too rigid or formulaic. Once you outgrow the beginner stage, you might want more freedom to explore your own approach rather than following a script.

4. Are you ready for your interviews? ↑

There’s no perfect roadmap, but if you keep practicing deliberately and learning from feedback through mock interviews, you’ll be well on your way to acing your system design interview.

As we’ve seen, practicing interviews can significantly boost your odds of landing your desired job. And truthfully, landing a job at a big tech company often results in a $50,000 per year or more increase in total compensation. In our experience, three or four coaching sessions worth ~$500 make a significant difference in your ability to land the job. That’s an ROI of 100x!

Use our mock interview service to connect with skilled interviewers from Google, Meta, and many other companies. 

Click here to book system design mock interviews with experienced FAANG interviewers.