Stop Reading About System Design.
Start Building It.

You have read the blog posts. You have watched the videos. But when the interviewer says "Design a URL shortener," you freeze. ScaleDojo is the interactive system design lab where you drag real components, build real architectures, and get instant AI feedback on your design decisions.

HLD Design Database Lab API Design AI Coach GenAI & AI Lab Personalized AI Roadmap Mock Interview
Start Your First Challenge Free

No credit card required. Build your first architecture in 5 minutes.

New to system design? Start with our learning paths

Trusted by engineers preparing for roles at top companies

What You Will Build

Practice the Exact Systems That Get Asked in Interviews

From URL shorteners to distributed message queues. Build the architectures that separate Senior from Staff engineers.

High-Level Design

HLD Architecture Challenges

Level 1Easy

The Static App

Design a single server static application.

Try It
Level 2Easy+15 XP

The 3-Tier Web App

Add database replication and user session management.

Level 3Easy+15 XP

URL Shortener

Design a highly-available URL shortening service like TinyURL.

Level 4Medium+25 XP

Rate Limiter

Design an API Rate Limiter to prevent DOS attacks.

Level 5Medium+25 XP

Notification System

Design a scalable multi-channel notification engine.

Level 7Hard+40 XP

Consistent Hashing

Implement load balancing and server ring partition.

Level 8HardPremium+50 XP

Distributed Message Queue

Design a high-throughput partitioned messaging queue like Kafka.

Level 9ExpertPremium+60 XP

Uber Driver Matcher

Design a low-latency driver matching service using geospatial indexing.

Pick any challenge and start building. Every design gets scored by AI with detailed architectural feedback.

Start Building Free

Three Steps to System Design Confidence

Go from theory to hands-on system design practice in minutes. No setup, no prerequisites.

1

Pick a Challenge

Choose real-world system design scenarios across HLD, LLD, API Design, GenAI, SQL Lab, and Mock Interview. Start with a URL shortener or go straight to designing a distributed message queue.

2

Build Your Architecture

Drag components onto an interactive canvas. Connect load balancers, databases, caches, and message queues. Make the same trade-off decisions you would face in a real system design interview.

3

Get Instant Feedback

Submit your design and receive a detailed review of your architectural choices. Identify gaps, fix mistakes, and understand why senior engineers make different decisions.

Chaos Engineering Simulator

Murphy's Lab:
If It Can Break, It Will

Building an architecture is only half the challenge. Knowing if it survives real-world failure is what separates good engineers from great ones. Murphy's Lab is a chaos engineering simulator built into every HLD system design challenge. Crash servers, spike traffic, sever connections, and watch your design respond under pressure in real time.

Inject real failure scenarios: server crashes, network partitions, traffic spikes
Watch live metrics update in real time: latency, throughput, error rate
Learn fault tolerance patterns: circuit breakers, retries, graceful degradation
Practice the same chaos engineering used at Netflix, Google, and AWS
Try Murphy's Lab Free
Simulation Active

247ms

Latency

12.4%

Error Rate

842 rps

Throughput

Web Server #2 crashed0:03
Load Balancer rerouting traffic0:04
Cache hit rate dropped to 34%0:06
Auto-recovery: Server #2 back online0:11
untitled.canvas
Load Test
Client
API Gateway
Auth
Service
Cache
DB

Draw Your Own Design

Not every idea fits a level. Sometimes you just want a blank canvas: an interview whiteboard, a design doc diagram, or something you're building at work and want to pressure-test before committing to it. Drop in cloud components, wire them up, and fire real traffic at it to see how it holds up.

40+ cloud components: load balancers, queues, caches, databases, gateways, and more
Live load test simulation, no account needed
Optional AI review that flags what looks missing or fragile
Export to PNG, SVG, or an animated diagram once you sign in (free)
Start Drawing Free

Prove It On Your Profile

Earn your first verifiable system design certificate in under a week. Each comes with a unique credential ID, a public verification page, and one-click sharing to LinkedIn and X.

ScaleDojo LogoScaleDojo

Certificate of Achievement

HLD Architecture Foundations

This certifies that

Your Name Here

Demonstrated proficiency in core distributed system design patterns including load balancing, caching, database replication, and URL shortening architectures.

Levels Completed

12 / 12

Credential ID

SD-A1B2-C3D4

Verified
0HLD Certificates
0LLD Certificates
0API Certificates
0GenAI Certificates
0AI Lab Certificates
0SQL Lab Certificates
0Forge Certificates
0Milestone & Master
Unique credential ID per certificate
Public verification page
One-click LinkedIn & X sharing
Tamper-proof & permanent
Start Earning Certificates

Free to start. No credit card required.

One Skill. Permanent Value.

Most system design courses charge $39 to $99 per month for video lectures. ScaleDojo gives you hands-on practice with AI feedback for a fraction of that cost. System design knowledge compounds. Engineers who truly understand distributed systems earn more, lead more, and build better.

7-day full refund policy. No questions asked.

Explorer
₹0
free forever, no card needed
  • Act 1 + Act 2: 12 HLD Architecture Levels
  • 10 LLD Schema Design Missions
  • 10 API Design Challenges
  • GenAI: Primer Levels
  • AI Lab: First 6 Challenges
  • SQL Lab: First 10 Cases
  • Personalized AI Roadmap access
  • Global Leaderboard Access
  • 20 Credits on signup + 5/day
  • 15 Credits per referral
  • 2 MYD Architectural Slots
Start Free
Pro
₹4,999₹3,999
800 credits + 225 premium levels /year
  • Everything in Explorer, plus:
  • 40 HLD, 30 LLD, 30 API & 40 GenAI
  • 20 AI Lab levels + 30 SQL Cases
  • 35 levels of Forge Algorithm lab
  • Mock Interview Arena access
  • 800 AI Credits instantly
  • 15 MYD Architectural Slots
  • AI-Powered Logic Analysis
  • Quizzes & Interview Signal on every Learn chapter
  • PRO badge on profile
  • Standard Support
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Architect
₹6,999₹5,599
all 546 challenges + 3,000 credits /year
  • Everything in Pro, plus:
  • All HLD, LLD, API, GenAI & AI Lab levels
  • All SQL Cases & Forge Algorithm lab levels
  • Mock Interview Arena: Unlimited
  • 3,000 AI Credits instantly
  • 50 MYD Architectural Slots
  • Full AI Reviews & Hints
  • Quizzes & Interview Signal on every Learn chapter
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Creator Spotlight

Creators Are Talking About ScaleDojo

Independent tech creators sharing ScaleDojo with their communities.

Vanshika Agarwal featuring ScaleDojo on LinkedIn
LinkedIn
Vanshika Agarwal
@vanshika.techlife178K

Okay real talk. When I was working at Google, I prepared for my Atlassian interview for months. I had notes, flashcards, could explain consistent hashing to my roommate at 2am without even thinking. Walked in feeling confident. First 10 minutes went well. Then the interviewer goes “alright, your primary database just went down. 10,000 users are hitting your system right now. Walk me through what happens.” I just... sat there. For way too long.

Read on LinkedIn
Shivam Garg featuring ScaleDojo on LinkedIn
LinkedIn
Shivam Garg
@shivam.garg136K+

From preparing for Google interviews to discovering a better way to practise System Design. Shivam shares the gap he experienced between learning System Design and actually designing systems, and why hands-on practice matters.

Read on LinkedIn
Archy Gupta featuring ScaleDojo on LinkedIn
LinkedIn
Archy Gupta
@archy.gupta803K

After working as SDE III at Google and mentoring a bunch of engineers through mock system design interviews, there's one thing I keep running into. So many of them can explain almost every concept I throw at them. Caching? Check. Sharding? Check. Message queues, load balancing? They knew it all. So I'd tweak the question a little. "Why this approach, for this problem, and not some other alternatives?" Silence. Almost every time.

Read on LinkedIn
Vanshika Agarwal featuring ScaleDojo on LinkedIn
LinkedIn
Vanshika Agarwal
@vanshika.techlife178K

Okay real talk. When I was working at Google, I prepared for my Atlassian interview for months. I had notes, flashcards, could explain consistent hashing to my roommate at 2am without even thinking. Walked in feeling confident. First 10 minutes went well. Then the interviewer goes “alright, your primary database just went down. 10,000 users are hitting your system right now. Walk me through what happens.” I just... sat there. For way too long.

Read on LinkedIn
Shivam Garg featuring ScaleDojo on LinkedIn
LinkedIn
Shivam Garg
@shivam.garg136K+

From preparing for Google interviews to discovering a better way to practise System Design. Shivam shares the gap he experienced between learning System Design and actually designing systems, and why hands-on practice matters.

Read on LinkedIn
Archy Gupta featuring ScaleDojo on LinkedIn
LinkedIn
Archy Gupta
@archy.gupta803K

After working as SDE III at Google and mentoring a bunch of engineers through mock system design interviews, there's one thing I keep running into. So many of them can explain almost every concept I throw at them. Caching? Check. Sharding? Check. Message queues, load balancing? They knew it all. So I'd tweak the question a little. "Why this approach, for this problem, and not some other alternatives?" Silence. Almost every time.

Read on LinkedIn
What Engineers Say

Real Feedback from Engineers Who Practice Here

SU
Suryansh

"One of the most valuable parts of ScaleDojo was the Wiki section and the origin files. Instead of just covering interview patterns, they helped me build a deep understanding of core system design concepts from the ground up. The content is well-structured, practical, and goes beyond surface-level explanations. Combined with the mentorship and interview preparation, it gave me the confidence to reason through system design problems rather than memorize answers. Highly recommended for anyone preparing for top-tier engineering interviews."

StudentIIT Kanpur
SG
Shreya Gupta

"ScaleDojo played a huge role in helping me crack system design interviews. The sessions were practical, focused on real interview scenarios, and helped me build a structured approach to tackling complex design problems. The feedback was honest, actionable, and significantly improved both my confidence and communication during interviews. Highly recommended for anyone serious about leveling up their system design skills."

SDE 2Google
K
k*****t@gmail.com

"ScaleDojo has a very well-organized System Design learning experience. The content is easy to follow, breaks down complex topics into simple concepts, and helps build a strong understanding step by step. I would highly recommend it and encourage every beginner or aspiring engineer to check it out."

ScaleDojo User
SB
Sujit Baral

"ScaleDojo has a clean and attractive user interface that makes learning web development concepts interesting and engaging. The mission-based learning approach is a great idea for practicing concepts step by step. The design is modern, and the platform feels beginner-friendly. It would be even better with more practical coding challenges, detailed explanations, and improved mobile responsiveness. Overall, it is a promising platform for developers to learn, practice, and improve their skills."

ScaleDojo User
AA
Ajay Ambre

"This is a great tool for practicing System Design. Learning by visually connecting the components helps to visualize the entire system better and the AI feedback is great."

ScaleDojo User
AG
Avirup Ghosh

"Interview prep can easily become too much about reading and not enough about actually thinking through problems. I used ScaleDojo during both my internship and placement preparation, and it helped me practice system design in a much more hands-on way. Designing systems, getting feedback, and breaking them under different scenarios made me much more confident in handling the kind of follow-up questions that interviews throw at you. Definitely worth trying if you're preparing for tech interviews. 😊"

Student (BTech CSE)IIT Mandi
VA
Vanshika Agarwal

"Okay real talk. When I was working at Google, I prepared for my Atlassian interview for months. I had notes, flashcards, could explain consistent hashing to my roommate at 2am without even thinking. Walked in feeling confident. First 10 minutes went well. Then the interviewer goes “alright, your primary database just went down. 10,000 users are hitting your system right now. Walk me through what happens.” I just... sat there. For way too long. Because I had read about failure scenarios. I had never actually sat with one and figured my way through it. Huge difference. That moment stayed with me for a long time. Most of our prep is passive. We consume. We do not build. We definitely do not break things and learn to fix them. So when I came across ScaleDojo I actually used it for a few weeks before posting anything here. You build architectures yourself on a canvas. Submit your design and get AI feedback on exactly what an interviewer would push back on. And Murphy’s Lab breaks your system in real time, crash a server, spike traffic, cut a network, watch your latency respond live. Then you fix it. That is the skill interviews are actually testing. If that blank moment sounds familiar, you are probably preparing the same way I was. Go try one challenge, free, no card needed. Come back and tell me if Murphy’s Lab did not completely change how you think about your architecture."

SDE-2Atlassian
VB
Vijay Bhatt

"Its great till now, the labs are very useful with topic help in daily learning goal and building concept incrementally, quizzes and challenge help checking your understanding of concept, live dashboard rating keep you motivated, very well built platform which makes learning fun."

Principal ArchitectKrista AI
NW
Nandini Wadaskar

"I loved the UI of this site. It provides an interactive learning experience. It is easy to understand. Config details are also helpful. It's a breakthrough way of learning system design."

ScaleDojo User
PA
Palak

"Really loved my experience with ScaleDojo. The platform is easy to use, and the way concepts are explained makes learning much simpler. I’ve genuinely learned practical things here that I can actually apply. Definitely worth it."

ScaleDojo User
SU
Suryansh

"One of the most valuable parts of ScaleDojo was the Wiki section and the origin files. Instead of just covering interview patterns, they helped me build a deep understanding of core system design concepts from the ground up. The content is well-structured, practical, and goes beyond surface-level explanations. Combined with the mentorship and interview preparation, it gave me the confidence to reason through system design problems rather than memorize answers. Highly recommended for anyone preparing for top-tier engineering interviews."

StudentIIT Kanpur
SG
Shreya Gupta

"ScaleDojo played a huge role in helping me crack system design interviews. The sessions were practical, focused on real interview scenarios, and helped me build a structured approach to tackling complex design problems. The feedback was honest, actionable, and significantly improved both my confidence and communication during interviews. Highly recommended for anyone serious about leveling up their system design skills."

SDE 2Google
K
k*****t@gmail.com

"ScaleDojo has a very well-organized System Design learning experience. The content is easy to follow, breaks down complex topics into simple concepts, and helps build a strong understanding step by step. I would highly recommend it and encourage every beginner or aspiring engineer to check it out."

ScaleDojo User
SB
Sujit Baral

"ScaleDojo has a clean and attractive user interface that makes learning web development concepts interesting and engaging. The mission-based learning approach is a great idea for practicing concepts step by step. The design is modern, and the platform feels beginner-friendly. It would be even better with more practical coding challenges, detailed explanations, and improved mobile responsiveness. Overall, it is a promising platform for developers to learn, practice, and improve their skills."

ScaleDojo User
AA
Ajay Ambre

"This is a great tool for practicing System Design. Learning by visually connecting the components helps to visualize the entire system better and the AI feedback is great."

ScaleDojo User
AG
Avirup Ghosh

"Interview prep can easily become too much about reading and not enough about actually thinking through problems. I used ScaleDojo during both my internship and placement preparation, and it helped me practice system design in a much more hands-on way. Designing systems, getting feedback, and breaking them under different scenarios made me much more confident in handling the kind of follow-up questions that interviews throw at you. Definitely worth trying if you're preparing for tech interviews. 😊"

Student (BTech CSE)IIT Mandi
VA
Vanshika Agarwal

"Okay real talk. When I was working at Google, I prepared for my Atlassian interview for months. I had notes, flashcards, could explain consistent hashing to my roommate at 2am without even thinking. Walked in feeling confident. First 10 minutes went well. Then the interviewer goes “alright, your primary database just went down. 10,000 users are hitting your system right now. Walk me through what happens.” I just... sat there. For way too long. Because I had read about failure scenarios. I had never actually sat with one and figured my way through it. Huge difference. That moment stayed with me for a long time. Most of our prep is passive. We consume. We do not build. We definitely do not break things and learn to fix them. So when I came across ScaleDojo I actually used it for a few weeks before posting anything here. You build architectures yourself on a canvas. Submit your design and get AI feedback on exactly what an interviewer would push back on. And Murphy’s Lab breaks your system in real time, crash a server, spike traffic, cut a network, watch your latency respond live. Then you fix it. That is the skill interviews are actually testing. If that blank moment sounds familiar, you are probably preparing the same way I was. Go try one challenge, free, no card needed. Come back and tell me if Murphy’s Lab did not completely change how you think about your architecture."

SDE-2Atlassian
VB
Vijay Bhatt

"Its great till now, the labs are very useful with topic help in daily learning goal and building concept incrementally, quizzes and challenge help checking your understanding of concept, live dashboard rating keep you motivated, very well built platform which makes learning fun."

Principal ArchitectKrista AI
NW
Nandini Wadaskar

"I loved the UI of this site. It provides an interactive learning experience. It is easy to understand. Config details are also helpful. It's a breakthrough way of learning system design."

ScaleDojo User
PA
Palak

"Really loved my experience with ScaleDojo. The platform is easy to use, and the way concepts are explained makes learning much simpler. I’ve genuinely learned practical things here that I can actually apply. Definitely worth it."

ScaleDojo User
RK
Ravi Kumar

"Usually, prep sites stop at high-level blocks. ScaleDojo goes down to the API specs, payload structures, and LLD table indexes. Designing microservices visually while specifying route constraints and database schemas feels incredibly close to actual design reviews we do internally. Excellent resource for anyone targeting Senior/Staff loops."

StudentNIT Karnataka
SS
simanta sarma

"It helped me implement those concepts in practice. Really helpful tool. I highly recommend this platform if you are in the computer science field."

Student (Btech in CSE)Gauhati University
RK
Rahat Khan Pathan

"I've recently started using ScaleDojo's System Design Lab, and honestly, it's been a fun way to learn system design beyond just reading theory. What I like most is being able to build an architecture, connect different components, and see how everything works together. Its easier to understand not just how things work, but also why we make certain design decisions and what trade-offs come with them. Looking forward to exploring more scenarios, making mistakes, and learning along the way. 🚀"

Senior Software EngineerCarga
G
g****h@gomail.edu.pl

"This tutorial website is an absolute lifesaver for mastering system design! It breaks down highly complex distributed systems architectures into clear, bite-sized, and beginner-friendly concepts. What makes it stand out is the perfect balance between deep-dive theory and practical, real-world case studies (like scaling Netflix or designing Twitter). The visual diagrams are incredibly sharp, making abstract concepts like load balancing, sharding, and caching instantly click."

ScaleDojo User
SG
Shivam Garg

"When I was preparing for my Google placement while in college, LeetCode was already a huge part of my DSA preparation. Hundreds of problems. Instant feedback. A clear way to know where I stood. System Design never really had that kind of practice loop. I read blogs, watch videos to understand caching, databases, queues, load balancers and all the usual concepts. But when I had to actually design a system myself, I kept getting stuck on the same questions: Why this database? Why a queue here? What happens when traffic goes 10x? What breaks first? That's when I realised that knowing System Design and actually designing a system are two very different things. Recently, a junior from IIT Ropar reached out asking me for System Design resources. While looking for something useful to send to her, I came across ScaleDojo."

SDE-3Google
AG
Archy Gupta

"After working as SDE III at Google and mentoring a bunch of engineers through mock system design interviews, there's one thing I keep running into. So many of them can explain almost every concept I throw at them. Caching? Check. Sharding? Check. Message queues, load balancing? They knew it all. So I'd tweak the question a little. "Why this approach, for this problem, and not some other alternatives?" Silence. Almost every time. Not because they didn't know the concepts. Because knowing what something does and knowing when to reach for it are two different skills, and only one actually gets tested in the room. Most of us prepare by consuming, videos, blogs, case studies on how Uber or Netflix solved something at scale. Eventually you start recognising patterns. But recognising a pattern is one thing. Defending it under pressure, live, with someone pushing back on every choice, is a lot harder. Should you cache here, or does it add complexity you don't actually need? Would relational hold up, or does this genuinely need NoSQL? Honestly, you only find that out by making the call yourself, getting it wrong once, and sitting with why. That's what grabbed my attention when I tried ScaleDojo. 👩‍💻 I opened the Architecture Lab, worked through the requirements, and designed the system within a budget. Then I threw it into Murphy's Lab, simulated real traffic, and watched my own design start to crack under it. I fixed what broke, submitted it, and got an AI backed review, not just on whether the diagram looked complete, but on whether the thinking behind it actually held up. That's the part I think most prep misses, treating this like something you memorise rather than something you get comfortable being wrong about first. That's the kind of practice I'd want more engineers to experience through scaledojo.dev ✌️"

SDE 3Google
SP
Suraj Prasad Soni

"I had a great experience using this system design website. The content is well-structured, easy to understand, and covers concepts in a practical way. It’s especially helpful for preparing for system design interviews and improving overall architectural thinking. Highly recommended!"

ScaleDojo User
H
h*****9@gmail.com

"It's really amazing to see something like this like I'm preparing something for a real interview It is helping me a lot so yeah end up Murphy's lab is also great to see the how the system is actually behaving under load spikes we flash types of simulation that's absolutely great"

ScaleDojo User
HB
Harsh Bhanushali

"I'm really impressed with ScaleDojo. The hands-on approach to learning system design, instant architecture reviews, detailed scoring, and intuitive interface make practicing distributed systems enjoyable and highly educational. This is one of the most innovative learning platforms I've used."

ScaleDojo User
KI
Kishnu

"The app is good. so far solved two HLD problems and it was great. The levelling up and the type of problems in each level is good. good progressive levelling"

ScaleDojo User
RK
Ravi Kumar

"Usually, prep sites stop at high-level blocks. ScaleDojo goes down to the API specs, payload structures, and LLD table indexes. Designing microservices visually while specifying route constraints and database schemas feels incredibly close to actual design reviews we do internally. Excellent resource for anyone targeting Senior/Staff loops."

StudentNIT Karnataka
SS
simanta sarma

"It helped me implement those concepts in practice. Really helpful tool. I highly recommend this platform if you are in the computer science field."

Student (Btech in CSE)Gauhati University
RK
Rahat Khan Pathan

"I've recently started using ScaleDojo's System Design Lab, and honestly, it's been a fun way to learn system design beyond just reading theory. What I like most is being able to build an architecture, connect different components, and see how everything works together. Its easier to understand not just how things work, but also why we make certain design decisions and what trade-offs come with them. Looking forward to exploring more scenarios, making mistakes, and learning along the way. 🚀"

Senior Software EngineerCarga
G
g****h@gomail.edu.pl

"This tutorial website is an absolute lifesaver for mastering system design! It breaks down highly complex distributed systems architectures into clear, bite-sized, and beginner-friendly concepts. What makes it stand out is the perfect balance between deep-dive theory and practical, real-world case studies (like scaling Netflix or designing Twitter). The visual diagrams are incredibly sharp, making abstract concepts like load balancing, sharding, and caching instantly click."

ScaleDojo User
SG
Shivam Garg

"When I was preparing for my Google placement while in college, LeetCode was already a huge part of my DSA preparation. Hundreds of problems. Instant feedback. A clear way to know where I stood. System Design never really had that kind of practice loop. I read blogs, watch videos to understand caching, databases, queues, load balancers and all the usual concepts. But when I had to actually design a system myself, I kept getting stuck on the same questions: Why this database? Why a queue here? What happens when traffic goes 10x? What breaks first? That's when I realised that knowing System Design and actually designing a system are two very different things. Recently, a junior from IIT Ropar reached out asking me for System Design resources. While looking for something useful to send to her, I came across ScaleDojo."

SDE-3Google
AG
Archy Gupta

"After working as SDE III at Google and mentoring a bunch of engineers through mock system design interviews, there's one thing I keep running into. So many of them can explain almost every concept I throw at them. Caching? Check. Sharding? Check. Message queues, load balancing? They knew it all. So I'd tweak the question a little. "Why this approach, for this problem, and not some other alternatives?" Silence. Almost every time. Not because they didn't know the concepts. Because knowing what something does and knowing when to reach for it are two different skills, and only one actually gets tested in the room. Most of us prepare by consuming, videos, blogs, case studies on how Uber or Netflix solved something at scale. Eventually you start recognising patterns. But recognising a pattern is one thing. Defending it under pressure, live, with someone pushing back on every choice, is a lot harder. Should you cache here, or does it add complexity you don't actually need? Would relational hold up, or does this genuinely need NoSQL? Honestly, you only find that out by making the call yourself, getting it wrong once, and sitting with why. That's what grabbed my attention when I tried ScaleDojo. 👩‍💻 I opened the Architecture Lab, worked through the requirements, and designed the system within a budget. Then I threw it into Murphy's Lab, simulated real traffic, and watched my own design start to crack under it. I fixed what broke, submitted it, and got an AI backed review, not just on whether the diagram looked complete, but on whether the thinking behind it actually held up. That's the part I think most prep misses, treating this like something you memorise rather than something you get comfortable being wrong about first. That's the kind of practice I'd want more engineers to experience through scaledojo.dev ✌️"

SDE 3Google
SP
Suraj Prasad Soni

"I had a great experience using this system design website. The content is well-structured, easy to understand, and covers concepts in a practical way. It’s especially helpful for preparing for system design interviews and improving overall architectural thinking. Highly recommended!"

ScaleDojo User
H
h*****9@gmail.com

"It's really amazing to see something like this like I'm preparing something for a real interview It is helping me a lot so yeah end up Murphy's lab is also great to see the how the system is actually behaving under load spikes we flash types of simulation that's absolutely great"

ScaleDojo User
HB
Harsh Bhanushali

"I'm really impressed with ScaleDojo. The hands-on approach to learning system design, instant architecture reviews, detailed scoring, and intuitive interface make practicing distributed systems enjoyable and highly educational. This is one of the most innovative learning platforms I've used."

ScaleDojo User
KI
Kishnu

"The app is good. so far solved two HLD problems and it was great. The levelling up and the type of problems in each level is good. good progressive levelling"

ScaleDojo User
Join the Community

The Research Behind the Systems You're Studying

Dense, original papers like MapReduce and Attention Is All You Need, broken down with diagrams and plain-language explanations.

Systems & Distributed

MapReduce: Simplified Data Processing on Large Clusters

Google turned web-scale data processing into two functions: map and reduce. This paper explains how that simple model let a framework handle parallelization, failures, and network efficiency automatically, and became the blueprint for Hadoop and the entire big-data ecosystem.

Jeffrey Dean, Sanjay Ghemawat · OSDI 2004

beginner· 5 min
Systems & Distributed

Brewer's Conjecture and the Feasibility of Consistent, Available, Partition-Tolerant Web Services (The CAP Theorem)

A distributed system split by a network partition must choose: answer with data that might be stale, or refuse to answer at all. Gilbert and Lynch turned Brewer's conjecture into a two-page proof that still decides how every database you use behaves when the network breaks.

Seth Gilbert, Nancy Lynch · ACM SIGACT News 2002

beginner· 5 min
Systems & Distributed

Dynamo: Amazon's Highly Available Key-value Store

Amazon's shopping cart can never say no. This paper shows how Dynamo trades strict consistency for always-on availability using consistent hashing, sloppy quorums, and vector clocks, the same ideas behind Cassandra and Riak today.

Giuseppe DeCandia, Werner Vogels et al. · SOSP 2007

intermediate· 7 min
AI & ML

Attention Is All You Need: The Transformer Architecture Explained

RNNs process language one word at a time, which is slow to train and struggles with long-range dependencies. This paper introduces the Transformer, which replaces recurrence entirely with self-attention and became the architecture behind every modern large language model.

Ashish Vaswani, Noam Shazeer et al. · NeurIPS 2017

advanced· 5 min

Frequently Asked
Questions

Everything about ScaleDojo's labs, pricing, and how to actually get better at system design - organized by topic so you can jump straight to what you need.

Your Next System Design Interview Is Coming

Every pattern you will drag onto the canvas started as a real engineering decision. The HLD Origin Files trace 8 chapters and 60 years of system design history, so you understand why load balancers, caches, and consistent hashing exist before you ever place one.

Read the Origin Files

Free to read. No signup required.