I joined this course mostly out of curiosity and a little “am I missing something everyone else knows?” feeling. I wasn’t expecting a mindset shift, but that’s honestly what I got.

What stood out to me is how simple system design felt when explained the right way. Instead of getting lost in fancy terms or patterns, the course focused on intuition: understanding the problem, breaking it down, evaluating trade-offs, and choosing what makes sense. It made me realise that solving hard problems isn’t about complexity, the real skill is simplifying things in a way that still works.

I’ve been following Arpit since my college days, and even back then I loved how he explained things so clearly and to the point. That same clarity carried through in this course, even the seemingly complicated topics felt simple and understandable.

The examples, discussions, and reasoning frameworks made the learning stick instead of just floating around as theory. I could actually connect things to how systems are built in the real world, and that gave me a lot more confidence in how I think and approach problems now.

Also really appreciated how patient and open Arpit was throughout the sessions. You could ask anything, basic, random, detailed, and he’d break it down with clarity and honesty, not buzzwords.

And yes, the classic line: “If you have a hard problem, don’t solve it.” Somehow makes me feel better about not overcomplicating things -- pure genius. xD

I have been following Arpit on Twitter for about 2 years now and always loved that each week led to some form of learning whether it was the papers he shared or the videos he produced. It made me interested in how to think than learning what to think.

I used to see the feedback on his course but always felt that I was not ready for it. This year is when I decided to give it a shot and my only regret would is that I didn't take it up earlier.

The systems that we learned to breakdown and the manner in which we did further reinforced the principle of "how to think" rather than what component would fit in.

We covered many topics/components which I have used many times but never stopped to think what it was meant to solve or to replace. The best learning that I take home from this course is that every time I come across a site, a product or a claim of high performance, my immediate thought would be to think of what they intended to solve and how to break it down into simple components.

As we covered:

• LSM trees

• Databases

• KV stores

• Load balancing

• Distributed schedulers

it becomes clear how nuanced the thought process is and how by simple layering of the requirements we can solve complex problems.

I would highly recommend this course to all people who are looking to learn or take the next step in their career.

Now onto all those exercises to complete :)

This cohort based course is a blessing in disguise (Disguise being the learning systems to the depth). The very idea of thinking, learning and doing what matters; this masterclass is a prime example of it coming to life. In this cohort we just were helped to understand not just what is more important but also why! This course can definitely help people understand the meeting point of business and innovation. And once you reach there; technology is one the sassiest tools you can leverage, impacting millions.

In every single decision of working with systems (from a bird-eyes view down to implementational challenges), we always had trade-offs discussed, new ideas appreciated, and every question that came onto the participants head spoken out answered (or given the right direction). We were taught to understand our own patterns of getting stuck, and also how to come out of it by making us understand where do these patterns are coming from. We understood the common patterns that are followed across the technology stack, and how to stitch them together. The very core of practicality where we re-used ideas, built on top of it with different nuances, understood the importance of SIMPLICITY.

I took the course to learn more, I had no aim for learning to interview only. And it worked wonders. I was able to grab more challenging initiatives at my work even when I was still attending the course.

Some key takeaways as an engineer that I found unique to this cohort:

• Framework of opposites, helps you identify trade-offs better. Also, might even help you solve problems with innovation trying to get into the middle grounds!

• You can understand complex systems by building simple prototypes.

• (Not discussed directly but personal takeaway) Low level designs are often derived from High level simplified choices for seemingly complex systems.

• When working with large scale, to save costs and making systems simpler, it's Space vs Time vs Correctness.

The course is very smartly curated where a lot of breadth in technology is covered linking one to other, helping you understand systems at scale is nothing but having Plan B for your Plans B. The course is enough to inculcate the importance of the three basic questions: Why, What, and How. I grew up with focusing only on ""Why"", and sessions with Arpit just helped me understand What and How are equally important, wherein you start to grasp in which situation either of the question has how much weightage!

For someone who thrives on engineering wonders this course a nitro-boost and for folks who are yet to identify their interests in engineering, this course is a reality identification on how beautiful engineering is.

I've always had a habit of reading an author's profile whenever I come across their blog. One day, while reading about the Morris Approximate Counter, I found your blog and discovered your courses. I came across the Redis Internals course and became very curious about it—especially the idea of writing a Redis-like database in Go, so I enrolled.

I genuinely enjoyed it and felt grateful to learn about Redis internals. Through this course, I also learned:

• Go

• OS kernel Epoll

• How a single thread can accept connections

Later, I came across the System Design Masterclass and enrolled in that as well. Once again, I felt truly blessed to understand how real systems work. For me, it's really an ocean of content to absorb. Every session was filled with so much information that I often fell behind, and I'm still trying to read more and make things clearer, especially while managing a busy office work schedule.

I really want to thank you for creating these courses.

Thank you so much, Arpit!!

:-)

"Master of Prototyping: The Catalyst for Deep System Understanding"

Arpit is a true master of prototyping, explaining system design from the business objective through the architectural plan right down to the code-level implementation.

I want to personally thank Arpit for this masterclass. He literally worked as a catalyst for me, enabling me to build systems quickly and understand the deep nuances of implementation, rather than just focusing on building high-level boxes. This shift in mindset and technical approach has been game-changing.

In the last eight weeks alone, I have successfully built and prototyped many systems, achieving end-to-end comprehension, writing robust code, and understanding every corner case.

For tangible proof, this distributed transactions repository on my GitHub was built in just the last 6-8 weeks, showcasing the practical results of the knowledge gained:

GitHub Repository: https://github.com/sanjivsingh/distributed_transactions/

I have been following you and your work for more than 3 years now. Whenever I used to wonder about a problem statement, I would try to solve it myself and then explore about it. More often than not, I would find a post or a video at your youtube channel/Linkedin about it. Your posts always probed me to think harder and dive deep into the systems. Be it:

• databases

• algorithms

• or just data flows

I used to think that I go in depth about anything I read/work/do.. Until I discovered your work! It made me realise how deep the sea is actually and I was literally just scraping the surface in most of the things.

Coming to the course, I have been trying to take this course a few times. But something or the other always came up. This time I managed to prioritise it above everything else and I am so glad I did that. The systems discussed during this course have all been highly practical. Even though I had already read about some of them, I learned so many new things. In single speaker style courses, we cannot have the raw and different ideas that just comes up naturally in cohort style courses. It opens up so many dimensions for us to think.

Thanks a lot for sharing all the knowledge with us. I hope one day I would also be in a position to give back to the community. :)

Of all the system design courses I've taken, Arpit's stands out as the best by far. There are countless courses online, often taught by instructors with little to no real-world experience — many are fresh graduates who've never solved complex system problems in practice.

Arpit, however, is different. His experience as a Staff Engineer brings tremendous practical depth to every lecture. He doesn't just teach concepts — he dives deep into the "why" and "how," backed by real-world insights that only come from hands-on experience.

What also sets his course apart is the level of engagement he maintains with the cohort. The constant interaction and energy he brings keep everyone alert, curious, and actively learning.

I highly recommend this course to anyone looking beyond just interview preparation — this is for those who want to build lasting, real-world expertise and long-term career growth.

Best decision of my life and got so many pointer while designing system.

What I like about your teaching method is that you give chance each one of us to speak and navigate to the proper path. You always push us to THINK that ""you only engineer going to implement this system"" . You have increased my TODO list which I have already started working on this.

What you have covered from OS level like semaphore to large distributed system along with the Usecase. I would it say it is AsliEngineering.

Thankyou so much for this.

PS : I am missing ""Copy paste"" and Blah blah bhu bhu bee bee""

What stood out to me was how brainstorming felt genuinely fun, instead of just drawing boxes on a whiteboard, we dug into real problems and solved them step by step.

The post-session prototyping exercises were gold. They pushed us to actually write our own solutions in code, not just talk theory. That hands-on approach makes the concepts stick because you're applying them immediately.

The recommended reading list was another highlight. The articles were packed with insights, and I ended up making detailed notes from them for future reference and implementation.

Overall, I thoroughly enjoyed the journey and would highly recommend the cohort to anyone serious about sharpening their system design skills.

I would highly recommend Arpit's System Design course to anyone who wants to truly understand how software applications are designed. Arpit doesn't just teach "what" to use — he takes you through the thought process of "how" and "why." You learn to evaluate questions like:

• which database to choose

• whether a load balancer is needed

• how to partition your data

• what kind of queuing mechanism makes sense

Arpit helps you develop a mindset where, by the end of the 8th week, you're naturally thinking about failure scenarios, trade-offs, how to address them, and how to build applications that can scale. As he says, system design is not about just adding boxes—it's about understanding what guarantees you're working towards, what constraints you're dealing with, and then building the system keeping those in mind.

One of the most important lessons for me was realizing that business and product come first, and engineering is just an enabler—something all of us engineers need to remember so we don't get carried away. Arpit has definitely reignited my curiosity for core engineering. Absolutely loved being part of his cohort!

The structure of the course—with thoughtfully designed pre-reads and post-reads—really helped deepen my understanding. It allowed me to explore topics both before and after the sessions, which was incredibly valuable.

Some of the classes, especially those on storage engines, were quite dense, but I understand those are inherently complex topics. Your teaching style—using hand gestures, varied intonation, and clear explanations—made it easier to grasp the subtle nuances.

While I only completed the implementation homework during the first two weeks, I consistently followed the video content. I realize assignments are time-consuming, but perhaps introducing a scorecard or leaderboard for assignment completion could further motivate the cohort and enhance engagement.

Above all, I truly appreciate your intelligence and integrity. In an industry where misinformation can spread easily, your commitment to sharing genuine knowledge stands out. Thank you for being a positive force in the learning community.

This cohort was a great experience. It reignited my interest in coding and gave me the motivation to move from just reading about system design to implementing the concepts. I now know how to dig deeper into complex topics and build a foundational understanding, which has been a major help.

The brainstorming sessions and Q&A were excellent. They taught me how to approach system design problems, make tradeoffs, and understand that a solution's value depends entirely on its constraints, not on being inherently good or bad.

The pre-reads, post-reads, and exercises were excellently curated, effectively strengthening our grasp of the topics covered in each session.

The real-world examples and analogies made the complex topics easier to understand.

Bonus: My morning routine is fixed.

I'd highly recommend this course to anyone looking to gain a solid understanding of system design and advance their career. Trust me, you will not regret it!

This is a knowledge goldmine which should be digged by everyone!

For a very long time I though system designs are just drawing boxes and only useful for the interview preps but Arpit proved it wrong. Now I can confidently say I can build and scale systems.

What I got as a bonus is the mental models and frameworks which I can use throughout my carrier and personal life.

The only thing I am sad about is the classes are over.

Long story short, If you are software engineer this is must for you! PERIOD!

When trying to learn/understand technical concepts I often watched Arpit's videos and found them interesting and refreshing from technical perspective, they went beyond just high-level explanations, this made me curious to pursue his System Design Masterclass.

While I was skeptical during enrolling given it was a substantial investment both in terms of time and money, my fears evaporated during the first session itself, they way Arpit puts up the challenge, sets the stage and creates the story to explain the concepts is out of the world, its just not a question – answer session or a monologue, every design concept is explained through a brainstorming as we would do in the real world, Arpit walks through why he chooses certain path while covering the pros and cons, "solve business problems", "framework of opposites" and re-application of concepts / solutions when solving the problems makes his teaching method unique.

I am glad that I did join (and could attend all the classes :)), it gave me a refreshing take at system design, helped me to understand the concepts with first principles in mind with the focus on solving business problems and there was never a dull moment. I loved the way he explained the technical concepts in a way that is easy to comprehend.

This masterclass is a "must-attend"(prefer the co-hort based learning over recorded videos) for anyone who is passionate about technology, eager to learn and enjoys in-depth technical conversations.

"It's class from the master – Arpit Bhayani".

Thank you Arpit, you are a blessing to the tech community, I wish you all the best in your efforts to spread "Asli Engineering"!

Man, I just love how you walk us through problems—it's like having that one awesome teacher who knows exactly when to give a little push. You've totally reignited my love for solving engineering stuff. Now I don't even flinch before jumping into a complex design. And honestly, that's because you gave us the right tools to break things down and really understand them. Even if something new pops up, I feel like, "Yeah, I got this—I can figure it out."

Also, your insight about starting from the business and product side before diving into engineering—that really stuck with me. I've taken that to heart, and it's changed the way I approach problems now.

I'm a frontend engineer (for the past 13 years), and until recently, I never really cared about backend architecture. Over time, that became a problem because I couldn't contribute or understand much on the backend side. But in the last 2 months, I actually sat down to read and understand the backend architecture. Something that used to feel totally alien now makes a lot of sense. That shift? 100% because of the way you've helped frame things. I'm even able to find improvements and optimizations in the backend flow now. I feel like Superman—you made me that!

And overall, it's just super inspiring to see you learning every single day. That mindset is contagious.

This year, I was looking for few courses to enhance my learning. I focused on two themes: designing scalable systems (both on-premise and cloud) and GenAI/LLMs with their production implementation. I browsed online learning platforms and spent a lot of time on YouTube diving into these topics. I watched several videos by Arpit on system design, including deep dives like PayPal's Juno DB and how Atlassian reduced latency by 70% using the sidecar pattern. I really enjoyed those.

Coincidentally, a teammate also mentioned Arpit and his course. I noticed on LinkedIn that it was the last day to enroll, with only 4 seats were left, so I jumped in and signed up. I'm so glad I did.

In my spare time, I enjoy coding to solve problems I encounter at work. Sometimes, time constraints and added complexity make things tricky. However, this course gave me a fresh perspective. It showed me how to brainstorm a small problem and arrive at a simple yet comprehensive final design. Each session covers 2-3 problems, with participants starting from, say, a 10% solution and building up to 100% in just three hours. It's been eye-opening.

The course has shifted how I approach problems. For instance, I recently built a framework to address a business problem and deployed it to production in just two weeks, with visible results. In total, it took me about 16 hours—not a masterpiece, but it works and solves the problem effectively. I've also created a backlog of other problems and outlined systematic approaches to tackle some of them. I've noticed a significant change in how I discuss system design and problem-solving with architects and developers. With AI tools and this new mindset, I'm solving problems more structurally.

Thank you, Arpit, for the incredible learning experience. I now see how patterns repeat across different systems. You're doing amazing work—keep it up! I look forward to meeting you in person someday. Additionally, I'll always remember these quotes from you which you used a lot during the course.

• Framework of opposites: Pull vs. push, sync vs. async, compute on-the-fly vs. precompute, etc.

• System design isn't just about drawing boxes: Write code to understand how the system will work in production, identify bottlenecks, and address them.

• Keep PoCs simple: Don't over engineer; include only what's necessary to solve the problem.

• Be empathetic to users: Always consider their perspective.

• Think like the only engineer who is working on the problem statement while designing the system.

Arpit is a great teacher, in this course I was pushed to think deep, think of the opposite, dig deep into the trade-offs of your system design. I got to learn few core mantras around which System Design revolves. "Money Well Spent", not just the content but the how it rewired my mental threads when approaching a problem. It was worth it to invest time in this course and 10x myself.

It sparked the curiosity, took away the fear to approach any problem statement, every thing is just copy paste. I will miss weekend class badly. every word that you said was a blessing that no money can buy. I feel more confident in solving problems, proactively take initiative to propose new ideas and solution. I was drifting away to non-tech, tech seemed boring, you just showed me that i haven't even explored 1% of the tech, I was not doing asli engineering. It rewired my mental threads. I make sure my juniors don't feel that way, I push them to think deep and make sure they know what is asli engineering.

Please share all the mantras in the post read of the course as well, I will pass them to my juniors.

Looking to update my skills set for building AI native Solution Architecture as that is the future. I feel my foundation is still not set, I need to make it strong.

Thanks a lot for everything you are doing. You are a legend.

This System Design Masterclass has been nothing short of life-changing for me. Before this, I'd often have a gut feeling about a solution but fumble when it came to explaining it clearly.

Now, thanks to Arpit's real-world examples, focus on practical applications, and unique approaches like thinking of opposites pattern, I can break down problems step-by-step and communicate my ideas with clarity and purpose.

The push to always think about implementation—writing pseudocode instead of just sketching boxes — has made me a more thoughtful and effective problem-solver.

The course didn't just teach me system design; it rewired how I think, especially with the added perspective of empathy in design. It's sparked a curiosity that I'm thrilled to bring to my job and personal projects.

I'm confident the skills and habits I've built here will help me make a real impact at work, and I can't wait to implement the Postreads' designs.

If you're serious about leveling up your system design game, this masterclass is an absolute must!

I have explored many youtubers, but Arpit's content is the closest to reality. This is not your regular "interview cracking series" but rather tackles problems from a pragmatic lens, seasoning you into a better engineer. His content justifies the "no-fluff" caption.

He not only covers component in details, every session considers implementation level details, tradeoffs, nuances and patterns that you won't find anywhere else. And while doing that, he also takes the intimidation away from all the buzz words.

I was worried before joining the cohort whether the cost would justify or whether i would learn anything at all since i had already covered many different system design playlists. But it was indeed WORTH IT, i learnt a great deal. His methodology is not a mere walkthrough of slides, but rather a brainstorming session which makes you think hard on design and implementation. You are not just a viewer, but rather an active/passive participant in this open ended brainstorming.

Overall, even (especially) if you think you know advanced concepts in theory, you should still take part in this cohort if you aspire to grow into staff or beyond. His sessions are not just technical, but also evolves your mindset as an engineer. Arpit's passion for engineering is contagious. If not for the content, one should simply join this cohort just to re-ignite that spark that once led them to choose this field.

A lot of us took up computer science to understand how these brilliant machines work and to build something meaningful with them. Personally, I've found that this intrinsic joy can sometimes get lost while working as a software engineer.

Every job has its share of grunt work:

• for some, it's coordinating with others to get changes released

• for others, it's navigating career ladders

In the midst of these tasks, it's natural to lose the spark and start feeling the mundaneness. That's exactly where I was before joining this cohort — like a ship that had lost its wind and was drifting without direction.

This cohort acted as a beacon for me. And though the waters were rough and the ship was thoroughly rocked by the storm over the last two months, it gave me a renewed sense of purpose. I could finally see a way forward — to become a software engineer in the truest sense, to become all the things I had once aspired to be.

Thank you — and I hope I get to return here someday!

I want to express my sincere gratitude to Arpit for his exceptional System Design Course. The emphasis on prototyping as a means to understand system components in isolation was invaluable, significantly reducing development cycles and providing deeper insights.

What truly set this course apart was the holistic approach—moving from business requirements to product specifications, and finally to engineering implementation. Every system we designed was grounded in data, with clear justifications for each component rather than treating them as mysterious black boxes. Even seemingly basic elements like load balancers were presented as natural solutions to specific problems.

The course delved into precise optimizations, teaching us the correct implementation of mutexes, file descriptors, epolls, and timestamp-based conflict resolution. Arpit encouraged us to avoid unnecessary jargon and hasty conclusions, instead focusing on first principles that can be applied universally.

I particularly appreciated learning how to anticipate extreme edge cases and consider opposing viewpoints to identify potential gaps in our designs. This methodical approach to system design has transformed my thinking and will undoubtedly improve my work for years to come.

Thank you, Arpit, for a truly enlightening learning experience.

I have been following Arpit for a while now, and I was always impressed by his ability to explain complex topics in a simple and engaging way. When I saw that he was offering a System Design course, I knew I had to join.

The course exceeded my expectations in every way. Arpit's teaching style is incredibly effective, and he has a unique ability to break down complex concepts into manageable pieces. The course is structured in a way that builds on previous knowledge, making it easy to follow along and understand the material.

One of the things I appreciated most about the course was the emphasis on practical application. Arpit encourages us to think critically about system design and to apply what we learn in real-world scenarios. The hands-on exercises and brainstorming sessions were particularly valuable, as they allowed us to put our knowledge into practice and learn from each other.

Overall, I highly recommend this course to anyone looking to improve their system design skills. Whether you're preparing for interviews or just want to deepen your understanding of the subject, this course is an excellent investment in your professional development.