Research The Interview Process For Companies
Each company has its own process for interviewing candidates and evaluates candidates along different core values, so do your homework! If you understand the mission and core values of the companies you’re applying to, you’ll not only understand more about the company’s culture and goals, you’ll also be better prepared to demonstrate those values and principles during the interview. We’ve put together an extensive catalog of interview guides that give you an inside look at the interview process and criteria for most tech companies. Here are a few examples:
- Google emphasizes technical competence in their interviews and often asks system design questions.
- interviewers tend to ask about your people skillslike ability to manage conflict or dealing with difficult team members.
Check out our full list of company interview guides here:
Adding Servers And Handling Failing Servers
So – what happens if one of the servers that we are sending traffic to dies? The hashing function still thinks there are 5 servers, and the mod operator generates a range from 0-4. But we only have 4 servers now that one has failed, and we are still sending it traffic. Oops.
Inversely, we could add a sixth server but that would never get any traffic because our mod operator is 5, and it will never yield a number that would include the newly added 6th server. Double oops.
// Let's add a 6th serverservers => // let's change the modulo operand to 6request#1 => hashes to 34 => 34 % 6 = 4 => send this request to servers => Server Erequest#2 => hashes to 23 => 23 % 6 = 5 => send this request to servers => Server Frequest#3 => hashes to 30 => 30 % 6 = 0 => send this request to servers => Server Arequest#4 => hashes to 14 => 14 % 6 = 2 => send this request to servers => Server C
We note that the server number after applying the mod changes .
In effect, the result is that half the requests are now being routed to new servers altogether, and we lose the benefits of previously cached data on the servers.
For example, request#4 used to go to Server E, but now goes to Server C. All the cached data relating to request#4 sitting on Server E is of no use since the request is now going to Server C. You can calculate a similar problem for where one of your servers dies, but the mod function keeps sending it requests.
Take Ownership Of Your Education
Big Tech interviews are both fairly standard and widely documented. There is a wealth of resources to prepare for the coding interview and a growing pile of systems design resources.
It’s easy to get lost in so much information: which is why you should make a plan on how you will get “interview-ready”.
Create a study plan with topics you want to cover for the interview types you’re expecting to have. Learn the theory, then practice this with practice and exercises where you create something from scratch: implementing a data structure, drawing up a diagram.
There is no shortage of people complaining about the difficult interview process Big Tech has. However, I know of no other industry where you can get a high-paying job with no college degree, no connections: purely through interviews that are fairly standard among the highest paying employers like Netflix, Airbnb, Uber, Facebook, Pinterest, and others.
Tech interviews being “standard” across the Big Tech makes preparing for these a high-leverage activity: study once, interview many times. Once you prepare, just make sure your software engineering resume grabs the attention of the recruiters.
Good luck – and if you are looking for more advice for senior and above interviews, I have some.
Recommended Reading: What Are Questions That Are Asked In Interviews
Dont Let The Interviewer Screw You Up
Remember, youre driving the interview. So dont expect the interviewer to necessarily ask you about all the areas youre expected to discuss to pass the interview. Its tricky though, because interviewers will guide you to areas to focus on, and some interviewers do ask lots of detailed questions. If you finish the interview and think phew, he didnt ask me about concurrency!, you probably did poorly.
This isnt just the hardest interview to prepare for, theyre also hard to conduct. Some interviewers will get off track honing in on tiny details or seem satisfied with very shallow answers. Dont forget, youre not just convincing the interviewer, youre convincing the interview panel. So dont be afraid to shift the direction of the conversation to cover areas where you can add more signal. Offer to cover things, I could make a diagram of this. Obviously, you dont want to be too pushy, if theyre asking you questions or directing you to a specific area, make sure you cover it. Avoiding answering a direct question is nearly always fatal in interviews.
Prepare For System Design Interviews
System design interviews are often asked in the engineering manager interview process, and require a different type of preparation than the people management interviews. These interviews often are in the format of “Design X” where you’ll be asked to discuss a technical implementation for a software product and consider trade-offs in building it.
For each system you design in the interview, consider how it affects the following aspects:
- Scalability: a system is scalable if it is designed so that it can handle additional load and will still operate efficiently.
- Reliability: a system is reliable if it can perform the function as expected, it can tolerate user mistakes, is good enough for the required use case, and it also prevents unauthorized access or abuse.
- Availability: a system is available if it is able to perform its functionality . Note reliability and availability are related but not the same. Reliability implies availability but availability does not imply reliability.
- Efficiency: a system is efficient if it is able to perform its functionality quickly. Latency, response time and bandwidth are all relevant metrics to measuring system efficiency.
- Maintainability: a system is maintainable if it easy to make operate smoothly, simple for new engineers to understand, and easy to modify for unanticipated use cases.
Review some of the system design fundamentals in our system design interview prep course to be fully prepared to ace these questions.
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Grokking The Advanced System Design Interview
This is an advanced course to learn about Software architecture and System Design from Educative, one of my favorite interactive learning platforms, and this course is like the advanced version of their popular Grokking The System Design course.
Designing systems and architecting software is one of the key responsibilities of a senior software engineer. But its difficult to master without practice, and few people have the chance to work on large-scale projects from the ground up.
This advanced System design course solves that problem. It provides you a chance to dive deep into the most common types of distributed systems including key-value store, distributed messaging and streaming system, distributed file storage systems, and more.
Along the way, you will also learn about a set of design patterns that are used to solve some of the most common problems in distributed systems. These are especially handy in system design interviews.
If you have an interview coming up, or youre interested in software design/architecture, then you can use this course to level up your system design skills and prepare better.
Here is the link to join this course Grokking the Advanced System Design Interview
Common Scenarios For Caching
Similarly, in software terms, if we end up relying on certain pieces of data often, we may want to cache that data so that our app performs faster.
This is often true when it’s faster to retrieve data from Memory rather than disk because of the latency in making network requests. In fact many websites are cached in CDNs so that it can be served to the end user much faster, and it reduces load on the backend servers.
Another context in which caching helps could be where your backend has to do some computationally intensive and time consuming work. Caching previous results that converts your lookup time from a linear O time to constant O time could be very advantageous.
Likewise, if your server has to make multiple network requests and API calls in order to compose the data that gets sent back to the requester, then caching data could reduce the number of network calls, and thus the latency.
If your system has a client , and a server and databases then caching can be inserted on the client , between the client and the server , or on the server itself. This would reduce over-the-network calls to the database.
So caching can occur at multiple points or levels in the system, including at the hardware level.
Read Also: How To Do A Group Interview
Top 5 Resources To Prepare For System Design Interview
System Design Interview preparation is like never ending story, there is no single source of learning that will give you true sense of confidence or short of completeness. But we cant just keep learning randomly over the internet or Youtube. I have doing research myself from long time and find out if you just learn from these 5 resources, this wont make you master but will give you confidence to crack system design interview. So In this post I am sharing after reading tons of interview experienced shared by selected candidates in top companies on various blogs.
Here are top 5 resources to prepare for System Design Interview.
Data Structures And Algorithms
Wait, this again? Yes! Turns out, this is actually important in designing software systems.
URL shortener? Makes me think of a hashing function. Oh, you need it to scale? Sharding might help. Concurrency? Redundancy? Generating keys becomes even more complicated. Same goes for designing an analytics system, a news feed, or a Q& A forum, each with its own set of common DS& A.
Dont forget to account for your scaling requirements, where analyzing runtime and memory complexity really becomes handy.
Recommended Reading: How To Crack Business Analyst Interview
Section : System Availability
Software engineers aim to build systems that are reliable. A reliable system is one that consistently satisfies a user’s needs, whenever that user seeks to have that need satisfied. A key component of that reliability is Availability.
It’s helpful to think of availability as the resiliency of a system. If a system is robust enough to handle failures in the network, database, servers etc, then it can generally be considered to be a fault-tolerant system – which makes it an available system.
Of course, a system is a sum of its parts in many senses, and each part needs to be highly available if availability is relevant to the end user experience of the site or app.
Tactic 5 Focus On What You Know Best
This tactic is simple focus on what you know best and apply your knowledge and experience as fully as you can.
For example, in our example with the chat app, if you choose to optimize for a non-functional requirement and your specialization is security talk about making the chat app secure for its customers. Look into authentication and message encryption.
If you are an experienced cloud infrastructure engineer focus on making the app cloud-native, pick the right services and explain your choices.
If you specialize in databases talk about the DB technology you would propose, how you would organise the data, and make the DB fast, cheap, and scalable.
To sum up, stick to the technologies and patterns you have used or at least tried previously. You have a lot of freedom in this interview to make decisions. If you can justify your choices and your design meets requirements you should be fine unless you propose something exotic or your interviewers are too opinionated. When your interviewers ask you a question, try to drive your answer to a familiar area when possible.
System Design Interview Questions And Answers
System design questions are typically ambiguous to allow you the opportunity to demonstrate your qualifications. You can ask questions before you respond to help you narrow the scope, give you direction and clarify any expectations.
Here are six common questions you may be asked during your system design interview:
System Design Interview Preparation Tips
System design, a process of defining, developing, and designing systems that satisfy a business or organizationâs specific needs and requirements, is a complex and challenging role to fill. The role is especially critical when itâs for designing larger systems with various constraints and requirements. Thus, a system design interview at FAANG or Tier-1 companies calls for experienced, dedicated, and competent candidates.
Therefore, to help you stand out, weâve underlined the essential tips needed for an effective system design interview preparation. Take a look:
1. Focus on What You Already Know
2. Understand the Problem
3. Break Down Your Solution
4. Practice the Pauses
6. Keep It Simple, Stupid â KISS
7. Always Justify Your Points
8. Be Updated With Current Tech Solutions and Practices
9. Communicate Your Ideas Clearly
10. Donât Stop Practicing
Read Also: How To Prepare For A Facebook Interview
Listen To The Interviewer
Even though youre meant to drive the interview, you still need to listen. These problems have lots of areas to go into depth, and the interviewer may be interested in one particular aspect. Make sure you listen to cues and go with the flow. As I mentioned before, ignoring or deflecting a direct question or request is a quick way to fail.
Tips To Prepare For And Crack Amazon System Design Interview Questions
As you may have noticed, the Amazon system design interview can be tricky. The questions are ambiguous, and you will have to deal with the unstructured nature of the discussion. However, with extra practice, youâll be prepared to handle anything the interviewers throw at you. Hereâs what you should do before and during the interview to make the best impression.
Amazon System Design Interview Process
The Amazon system design interview is typically conducted later in the interview process. If you pass the phone screening round, you’ll be invited for a video interview. This interview lasts for about 45 to 60 minutes. It will involve a hiring manager or a peer of the same level as your role. They will ask more in-depth questions about your resume.
This round is where you should be prepared to answer coding and system design questions.
To learn more, read .
What Happens Behind The Scenes
If things go well at your onsite interviews, here is what the final steps of the process look like:
- Interviewers submit feedback
- Senior leader and compensation committee review
- Final executive review
- You get an offer
After your onsite, your interviewers will all submit their feedback usually within two to three days. This feedback will then be reviewed by a hiring committee, along with your resume, internal referrals, and any past work you have submitted. At this stage, the hiring committee will make a recommendation on whether Google should hire you or not.
If the committee recommends that you get hired, you’ll usually start your team matching process. In other words, you’ll talk to hiring managers and one or several of them will need to be willing to take you in their team in order for you to get an offer from the company.
In parallel, the hiring committee recommendation will be reviewed and validated by a senior manager and a compensation committee who will decide how much money you are offered. Finally, if you are interviewing for a senior role, a senior Google executive will review a summary of your candidacy and compensation before the offer is sent to you.
As you’ve probably gathered by now, Google goes to great lengths to avoid hiring the wrong candidates. This hiring process with multiple levels of validations helps them scale their teams while maintaining a high caliber of employee. But it also means that the typical process can spread over multiple months.
Recommended Reading: How To Prepare For Amazon Coding Interview
What Is Amazon Interview Process
A Step-by-Step Approach to Acing your System Design Interview
Creating a Design System: The Step-by-Step Guide
12 Tips for How to Succeed in a Job Interview