System design can be a huge leap forward in your career both in terms of money and satisfaction you get from your job. But if your previous job was focused on working closely on one of the components of a system, it can be hard to switch to high-level thinking

Imagine switching from roofing to architectural design. Instead of knowing the ins and outs of making one component, you need to develop a system of components that work well together. This is why so many people fail in system design interviews. They don’t understand what the interviewer wants to hear from them.

What are interviewers looking for?

You walk into an interview, ready to discuss the pros and cons of using NoSQL, fine details of implementing map-reduce, and the possibilities of using the newest node library. What do they ask you? Design Netflix from scratch.

This leaves many interviewees puzzled, and they do two crucial mistakes. The first mistake is focusing too much on the service that already exists. The interviewer doesn’t want to know how Netflix or Twitter is actually made. Rather, they want to see your thought process that goes into creating a similar system.

The second mistake is focusing too much on details. That’s not what you need to do, at least not at first. The technical knowledge and the ability to solve bottlenecks is great, but your main goal for such interviews should be understanding the type of system you need to develop and figuring out the optimal way of solving user problems.

How to ace a system design interview: A step by step guide

Now that you know the direction, let’s go through the interview, step by step.

Step 0: Get good

Preparing for the interview starts months before you arrive at the office. You need to work on gaining knowledge and acquiring skills to be sure that you have what it takes to crack it.

This includes a lot of reading. Start with following high scalability and getting yourself a copy of Martin Klepmann’s Designing Data-Intensive Applications. It’s a great place to start if you have limited experience with system designs.

If you have the knowledge but struggle to apply it to real-world problems, try hosting brainstorming sessions with your pals. After all, trying to design Twitter from scratch can be fun when your employment doesn’t rely on it.

You can go even further and attend a hackathon to try implementing your system design knowledge in practice and get expert advice on it. When you feel confident about your skills, start polishing them before the interview. For instance, you can focus your practice on the typical cases interviewers offer.

In most cases, the interviewer will ask you to design one of the following services:

• URL shortener
• Social network
• Messenger
• Video streaming
• File storage
• Search engine

If you know a bit about each of these services, you’re already on the right track. To gain even more confidence before the actual interview, attend a mock one. You can do it online, and instead of “we’ll call you back”, you’ll receive an expert opinion on your performance.

Step 1: Define the key assumptions about the system

Now, let’s say you’ve made it to the interview. Given the number of applications big tech companies receive, it’s already an achievement. You feel good about yourself, and when the interviewer asks you to develop something like Facebook, you start talking about peculiarities of data storage and what is the best way to create a dynamic feed.

That’s not what they expect to hear. First, you need to understand what kind of system are you building. What is the intended audience? What problems are they solving with this service? You’ll need to answer those questions before you can go any further.

In many cases, the interviewer won’t know the answer. Why? Here’s a very important thing about system design interviews: it’s not about giving the correct answer to a well-defined problem, but it’s about your ability to define the open-ended problem and solve it creatively.

This means you can pretty much decide on these key assumptions together with the interviewer.

Step 2: Define the key features

Once that is out of the way, your next step is defining what kind of features your hypothetical service must possess. Even though your task is designing an already existing service from scratch, it doesn’t mean they should be identical.

For instance, if you’re tasked with designing Facebook, you can take the features this social media has as the basis and work from that. Think of ways you can combine Messenger and Facebook into one app instead of two or suggest how to make ads more user-friendly.

If you’re tasked with developing a Discord-like chat, you’ll need to include secure chat rooms with stable voice chat features. You can also suggest a streaming option. If you need to develop a digital product marketplace such as Pro Essay Writer, you’ll need to combine features like dynamic display of offers, secure access to database, and several payment options. You can throw in a Ai live chat or a monitoring feature to make sure the freelancer the user has hired is busy working on the project.

This will show the interviewers that you’re not only capable of reverse-engineering a service, but actually thinking about the problems customers face and solving them.

Step 3: Define the scale

While the system you design should be scalable, you need to start somewhere. This is why you need to define the scale of the system at first. Think about the read-to-write ratio, the number of concurrent requests the system should expect, and various data limitations.

Once you define these parameters together with your interviewer, you can think of the best way to make that system work well and be scalable. But before that, there’s one more step.

Step 4: Define the data model

Before you can design the hypothetical system, you need to define how you’re going to process data. Find out the main inputs and outputs, how they’re going to be stored, and how the data will flow.

This doesn’t require you to know every little aspect of implementing MongoDB or the latest MySQL library. If you know what database would serve the purpose better, it’s going to be enough. Remember, you don’t need to go into detail too much at this stage.

Step 5: Design the high-level system

By this time, you should have all the information necessary to design the system your interviewer wants. Ideally, you should be no more than 15-20 minutes into the interview.

Start with the entry-points and work your way up to the database. If the interview room has a whiteboard, it’s a great opportunity to visualize your ideas, but even a sheet of paper will do. Draw the architecture that’s needed to support all user and API interactions and present a decent response time.

Don’t be afraid to change the layout of the system on the go. Interviewers don’t care about you making mistakes. They want to see if you’re able to iterate your ideas and improve as you go along.

Step 6: Look for bottlenecks

Once your version of the system seems more or less final, you can get down to details. Look for possible bottlenecks that can slow down or hinder the functions of the system. It’s also okay to take the interviewer’s advice on this. In many cases, the interviewer is an expert on the topic, so you’ll only show your readiness to learn and improve by this.

Find out the bottlenecks and come up with ways of eliminating them either by redesigning a part of the system, or scaling up the hardware.

Step 7: Go in-depth on the subsystem you know well

This is an optional step, but many interviewers ask you to go through this as well. You’ll have to go low-level and elaborate on a subsystem. If you can, steer the conversation to the one you know best.

There’s no shame in admitting you don’t know much about a certain subsystem. After all, you’re no Renaissance man, and the company you’re applying to has teams of experts working on each subsystem, so you’ll have plenty of opportunities to consult with them.

Show off the knowledge you have, and move to the next step.

Step 8: Acknowledge the trade-offs

No system is ideal, and a good system design engineer knows that well. Let the interviewer understand what trade-offs did you make to let the system work well at this stage.

Stay in touch

With that, your 45-minute interview should be over, and the interviewer would be either impressed or bored with your take on the problem. Regardless, you should try to stay in touch with them to increase your chances of getting hired. At the very least, you may get an expert opinion on what went wrong.

If you’ve failed the interview, don’t stop in your tracks. It’s just an opportunity to learn more and practice more. Join Hackathons and do mock interviews to up your skills, and you’ll get the job you’ve been dreaming about.

This blog is a guest contribution from Harsh Goel, Founder@ InterviewCamp.io – Online Bootcamp for Technical Interviews

Machine Learning or Blockchain might be the next big thing, but interview problem-solving is the skill of the decade.

Here is a step-by-step plan to improve your data structure and algorithm skills:

Step 1: Understand Depth vs. Breadth

We all have that friend who has solved 500 coding problems. They love to wear it as a badge of honor. But when it comes to interviews, they fail miserably. This is a very common scenario. It’s what we call the “Breadth-Only” approach. They are solely focused on solving as many problems as they can.

The Breadth-Only approach has a problem—you don’t build a strong foundation. Interviews require deep problem-solving knowledge and the ability to code fast and accurately. You only develop these skills with focused preparation.

Here’s a counter-intuitive approach that works better:

Focus on less problems, not more

This is comforting, right? Who wants to focus on 500 problems when you can focus on 100?

But here’s the key—you want to learn them in depth. This is where depth comes in.

When you analyze a problem in depth, it means:

1. You can code it quickly
2. You can code it with correct syntax, which means you are good at the language
3. You can write clean code in one go, because it’s second nature to you
4. You can apply the same code to a new problem quickly
5. You know the data structure you are using and can implement it if asked to

To achieve this, you need to focus on a few representative problems (around 100 works well.) Solve them a few times and you’ll start seeing patterns. You also start getting better at the coding part.

So you’ve covered Depth, congratulations! You have acquired a solid base.

You can now go all out and solve as many problems as you want. And best of all, you won’t need to code many of them. Figure out a solution, and if it’s similar to one of your core problems (which it often is), you’re done. No need to actually code and debug it because you’re already good at that.

Step 2: Start the Depth-First Approach—make a list of core questions

Identify a list of ~100 core problems. Many sites give you 100 curated problems.

Here’s another way:

Get these two books:

1. Elements of Programming Interviews
2. Cracking the Coding Interview.

Collectively, they give you a good variety of hand-picked problems. If you want a structured course for this, check out InterviewCamp.io

Step 3: Master each data structure.

Now that you have finalized your list, start with the basics. Know every data structure.

Learn how to use each data structure in your language.

Also, learn how to implement them. Yes, implement them by hand. Many people ignore this, but it’s extremely important. Interviewers can ask you about data structure internals. Many problems modify data structures or re-engineer them for a specific use case. To utilize them fully, you need to know how they work.

For example:

Interviewer: “So you initialized an array-backed list. Good. Now let’s say you reach its capacity, what happens when you try to add another element?”

Candidate: *blank* “What do you mean capacity? I can keep adding elements to this list.”

Interviewer: *facepalm*

In this case, the candidate had been using Python, and there’s no concept of list capacity. You just keep adding elements. But that’s not what happens under the hood. You need to know what data structures back a list, and how that works.

Here’s another example:

Let’s say you’re asked to Implement a Queue using just Stacks (a popular question). This is a modified data structure. If you haven’t implemented either of those before, you’ll have trouble getting started.

Now, this doesn’t mean you need to know every implementation’s code. Some data structures are pretty hard to implement – for example, deleting a node from a Binary Search Tree is not trivial to code. But you should know how it works.

webflow.hackerearth.com/blog/leadership-personality-behaviors

Further Reading

Would you like to get updates once a month on our latest articles? We won't spam, we promise. Subscribe now to The HackerEarth Blog!

Here is a list of data structures to master :

• Arrays and Lists
• 2D Arrays
• Strings
• Linked List
• Stack
• Queue
• Hash Table & Hash Set
• Heap
• Graphs
• Binary Tree
• Binary Search Tree
• Trie

How to go about it? Let’s say your core problems are divided by data structure. You can master each data structure when you start each section. Or, you can master them all at the beginning. Do what works for you.

(Check HackerEarth Data Structure & Algorithm practice)

Step 4: Spaced Repetition

Alright. You made a list of questions and you started solving them. Here’s a common question we get:

“I solve many questions but can’t solve them a week later! How do I remember solutions?”

The key is to not remember solutions. The key is to practice them. When you see a problem, you should immediately be able to break it down and re-create the solution. This is different from rote learning. You’re recognizing different components, breaking them down and solving the problem.

The best technique we’ve seen – solve the problem again in 3 days. Then in a week. Then in a month. It will become second nature to you.

Step 5: Isolate techniques that are reused. Isolate actual code blocks.

This is where the Depth-First approach gets exciting. As you solve these problems, you’ll start to notice patterns.

Let’s say you solved 5 problems that used Binary Search. You can isolate the Binary Search code and practice it over and over. You know it will be used in similar problems.

And this is one of many techniques you can isolate. Here are some other common ones:

• Depth First Search
• Recursion + Memoization
• Hash Table + Linked List combination
• Searching a Binary Tree etc.

Now, you have a collection of techniques you can apply to new problems.

Step 6: Now, it’s time for Breadth.

Let’s say you’ve mastered your core problems. Using common data structures is second nature to you. You can now look beyond your core set. Because you’ve implemented so many techniques already, you don’t even have to code all the new questions.

During this time, try to solve realistic interview problems. Once you get good, there’s a tendency to focus on really hard problems. The thought process is – “if I can solve these really hard problems, then interview problems will be a piece of cake!”. That’s not usually the case. Techniques in really hard problems often have nothing to do with interview-level problems.

Step 7: Practice on paper

We recommend practicing on paper at some point in your prep. When you code without an IDE and Stack Overflow, it takes you away from your comfort zone.

Here are some benefits of practicing on paper:

1. You’re forced to plan your code before writing. You can’t just go back and retype.
2. You will start learning correct language syntax and data structure usage. With an IDE, code used to write itself.
3. You can take a paper and pen anywhere with you to practice.

And more importantly, it is a realistic simulation of a whiteboard interview.

Congratulations, you’re now a pro! Let’s get those interviews rolling.

Also read – Top 7 algorithms and data structures every programmer should know about

There are a lot of elements to a successful onboarding strategy, but here we’ll talk about one very easy yet effective step that’s necessary for all organizations: a welcome email or letter to the new employee.

You’ll want to write an authentic, engaging, yet clear and straightforward email or letter, and that’s surprisingly not as hard to do as you might think. While there’s some room for flexibility and creativity, especially when it comes to the details of the organization, we’ve prepared a handy template that will help guide you through the process.

The Basics

The welcome letter is crucial because it’s the first real concrete welcome to the organization message for a new hire. It’s a way to verbalize how excited the company is to work with this person, gives them an overview of what they need to know and the next steps, and is also a good way to remember their start in the company later on.

Roberta Young, an HR manager at Paper Fellows, explains that “the welcome letter must be written by the manager and not by another employee. This is a way to start the relationship between manager and employee on a positive note from the first day, and by writing a genuine and friendly letter, you’re creating employee engagement and trust from the get go.”

Conduct accurate coding assessments to hire the right developers. Find out more.

The Breakdown

The first thing your welcome letter should have is the welcome to the employee. Then, you should introduce yourself and explain in a couple of short points how you came to be in this position in the organization, even sharing your own experience as a new employee if relevant. This will build trust between you, the manager, and the new hire. Don’t overshare, as a lot of this can be discussed in person also.

The next part of the letter should cover the logistics of their first day, like where and when to go, what to look forward to, what to prepare in advance, and even share the dress code if there is one.

Finally, give a brief overview of the onboarding journey and what the steps to becoming a full employee look like. This is a good place to mention the positives about the employee that got them hired and how you see them fitting into the organization long term.

It’s important that your welcome letter or email is written professionally and without mistakes to give a good first impression of the company. Here are some tools that can help you craft the perfect email:

• Via Writing and Let’s Go and Learn are writing guides to get you started if you’re drawing a blank.
• Essayroo and Do My Assignment Online are two excellent editing tools that will look at your email and identify errors in flow or consistency. These tools are recommended by Best Assignment Services.
• Academized and State of Writing are grammar resources that will double check your welcome letter for any mistakes or typos.
• Boom Essays and UK Writings are online proofreading tools to get a second opinion on any spelling mistakes. They are well reviewed at UK Top Writers and for good reason.
• Beamfox and Talmundo are candidates preboarding software that personalizes candidate preboarding from the day candidate sign the contract to the onboarding. They have an intensive list of all possible templates required for great onboarding.
• Academadvisor and My Writing Way are writing blogs that can help walk you through the process from start to finish and give you some good inspiration.

Do’s and Don’ts of Welcome Emails

Here are some tips that will help you create great emails for your new employees:

• • Do make it personal
  • Don’t forget to send additional materials
  • Do send them a prepared schedule
  • Do make sure you include your company culture and spirit into your email
  • Don’t drown them in new information
  • Do set goals right away

Welcome email Template#1

Dear <Name>,

Welcome to <company name>! We’re so excited to have you join our expanding team. I know that your hard work and great sense of humor will fit in well with the rest of the group here.

We spoke a bit during the interview process, but I’m looking forward to getting to know you better. I’ve been with this company for <how many years>, and every day I continue to learn more. As your manager, I’m excited to see how you’ll grow with the team and the company and what you can bring to the table.

I’ll see you on <date and time> at <exact location>. We’ll grab some coffee and have an informal tour of the office to meet the rest of the team, then we’ll get all your paperwork sorted and get you started on your training journey. No need to bring anything – just yourself!

I’m excited to see you tackle this amazing journey, learn from the team, and eventually make your mark in the <industry or role>.

Looking forward to <date>,

<Your name and title>

Conduct remote interviews effortlessly with FaceCode. Find out more.

Welcome email Template#2

Dear [Employee’s name],

We are all really excited to welcome you to our team! As agreed, your start date is [date.] We expect you to be in our offices by [time] and our dress code is [casual/ business casual.]

[If necessary, remind your employee that they need to bring their ID/ paperwork.]

At [Company name], we care about giving our employees everything they need to perform their best. As you will soon see, we have prepared your workstation with all necessary equipment. Our team will help you setup your computer, software and online accounts on your first day. [Plus, if applicable, mention any extra things you’ve prepared for your new hire, like a parking spot, a coffee mug with their name or a company t-shirt.]

We’ve planned your first days to help you settle in properly. You can find more details in the enclosed agenda. As you will see, you’ll have plenty of time to read and complete your employment paperwork (HR will be there to help you during this process!) You will also meet with your hiring manager to discuss your first steps. For your first week, we have also planned a few training sessions to give you a better understanding of our company and operations.

Our team is excited to meet you and look forward to introducing themselves to you during [planned event/ lunchtime].

If you have any questions prior to your arrival, please feel free to email or call me and I’ll be more than happy to help you.

We are looking forward to working with you and seeing you achieve great things!

Best regards,

[Your name]

[Your signature]

Now that you’ve learned all the basics and seen an example, it’s time to start writing your own welcome letter. Good luck!

Popular posts like this:

1. 1. What Recruiters Can Learn from Job Seekers
   2. How to hire the best developer talent at your next career fair
   3. 6 steps to create a detailed recruiting budget

2020 looks like it’s going to be a phenomenal year for the recruitment industry. As a tech assessment company, we’re lucky to be able to regularly swap ideas with HR leaders, visit conferences, and read up on industry experts’ findings. Based on our findings on the latest hiring trends, here’s the scoop:

1. An increase in employee referrals and referral programs

82% of employers rated employee referrals above all other sources for generating the best return on investment (ROI) – source: careerbuilder

There is a reason why they say that two heads are better than one. Your team is first-hand proof of what you stand for as an employer brand. Hence, it is very important that they are your strongest advocates. This recruiting trend is one of the main reasons why we will see an increased focus on collaborative hiring in the upcoming year.

Here is a 5 step guide to building the perfect employee referral program:

1. 1. Determine the goal – Have a clear vision of what your referral program should accomplish. Is it to boost diversity? Is it to increase your remote workforce? Once you have this broad goal set, get more specific—check how you can increase the percentage of referrals or how to improve the quality of referrals.
   2. Create an easy, employee-friendly process – The less work an employee has to do to refer a candidate, the more successful the program will be.
   3. Train your workforce – Train your workforce on the following:
      • How to use the referral system
      • An understanding of what your company is looking for in a referred candidate
      • What employees can expect when they refer a candidate
   4. Don’t forget to say kudos – Recognize employees who are referring candidates. At HackerEarth, we run a cool referral program for our employees. Perks include handsome referral bonuses and a chance to win some awesome tech gadgets.
   5. Measure your efforts – Some useful metrics to track your referral program are:
      • What % of your hires have come from referrals
      • The % of qualified referrals (referrals who meet the mark)
      • How engaged is your workforce in the referral program
      • What is the quality of hires from the referral program

2. A shift from resume-based hiring to non-conventional hiring

Did you know that Google receives close to 2 million job applications in a year and recruiters spend an average of 6 seconds looking at a candidate’s resume– source: The Ladders

Resumes are passé and recruiters are using new hiring tactics like never before. Here are some non-conventional hiring tips for shortlisting candidates:

• Administer a personality test earlier in the hiring process – Good developers, for example, are known to exhibit traits that mark high performance such as teamwork, analytical thinking, and judgment. Looking out for such traits in the initial stages of evaluation can help you shortlist candidates who could be the right fit for the role.
• Gamify your hiring process – Using Artificial Intelligence in the hiring process helps measure specific elements like technical skills, vocabulary, facial expressions, and question response speed. These factors can also help reveal clues about an applicant’s education, intelligence, personality, and emotional stability. For example, Unilever makes use of Pymetrics to recruit and sort job applicants.

“Recruitment is part of a broader trend of using gamification in the workplace. Gamification uses game mechanics and experience design to engage users and solve real-world problems, by tapping into human psychology and rewarding positive behaviors in the workplace. Traditional recruitment processes can be intimidating and stressful for candidates and adding elements of games can make the experience more enjoyable as well as bringing out deeper aspects of the candidate’s psychology and behavioral styles.” – Kerstin Oberprieler, Gamification Expert

• Use skill-based assessments – Looking to test and filter candidates on job competency? One great way of doing this is to incorporate skill-based assessments in your hiring process. In fact, one should not only be looking at skill-based assessments for screening, but the entire hiring process should be based on skills.

Conduct accurate coding assessments with HackerEarth. Find out more.

3. A boom in Gen Z hiring

Did you know that 61 million Gen Zers will enter the US workforce in the coming years– source: CNBC

Gen Zers will form a major chunk of the workforce in the coming years. This makes it very important for recruiters to understand their needs and wants. Both millennials and Gen Zers come with their own skill sets yet both could not be more different from one another. With the oldest of Gen Zers being in the age group of 23 to 25, most recruiters can’t use the same tactics which work for millennials.

To solve this puzzle, recruiters need to understand why recruiting Gen Z is so different, what they care and don’t care about the work/workplace, and how to effectively recruit and retain this talent. You can find some great hacks on this hiring trend of recruiting Gen Zers in this webinar.

4. Embracing remote work

Did you know that in the past two years alone, there’s been a 78% increase in LinkedIn job posts advertising flexible work arrangements? – source: Remote year

Every distributed team looks different, but they all have one thing in common: they’re the future of work. Since distributed teams are set to become the norm, it’s key that you adapt and update your management skills for this new mode of work.



To be on point with this hiring trend, here are some strategies to get you into a remote management mindset for great results with remote teams:

1. Think remote-first -Start with how to manage teams remotely—maybe through a tool like Trello or with daily stand-ups via Zoom—and then see how this fits into the in-office group.
2. Use the same communication channels - Make sure you’re using the same processes with your in-office and remote workers. Slack is a great solution for communication. It is immediate and leaves a digital paper trail so that deadlines and expectations are clearly agreed upon.
3. Collaborate using digital management tools - There are great digital tools out there to boost collaboration. Tools like Slack, Asana, or Basecamp can promote easy and instant communication so that your team stays connected and nimble.
4. Create social spaces online - In addition to getting work done, you should also build relationships within your distributed team. This will make your team members feel more unified as not feeling part of the team can be a big challenge for working remotely. Some ideas include channels or boards for sharing photos of your weekend plans, social events such as virtual happy hours, or even a Friday email sharing stories from the week.
5. Celebrate success in public - When remote workers feel “out of the loop,” it’s usually because they don’t see how they’re positively impacting the team or company. One way to solve this isolation is to communicate success stories across the company. Send a weekly email of successes or use a Slack channel to give regular shout outs to good work. Your workers will feel appreciated and more engaged in their job.

---

Conduct remote coding interviews effortlessly with FaceCode.

---

5. Looking beyond the conventional skill set

Did you know that 84% of recruiters say culture fit is a prominent factor in the hiring process - source: cubiks



Competition for top talent is at an all time high with recruiters finding it challenging to hire candidates who fit both culturally and skill-wise. Most organizations are now looking beyond industry standards and are hiring candidates who are eager to learn.



According to the balance careers, here’s how you can create your own cross-training program for candidates:

1. Look within your own function for opportunities to cross-train on assignments.
2. Establish a formal job rotation across your organization.
3. Offer incentives for certifying on a variety of positions, functions, systems or products.
4. Measure employee feedback on their interest in and satisfaction with the cross-training work. Ask for their ideas on improving the initiative. Consider generating a dynamic QR code and integrating it to gather employee feedback on your cross-training program. Analyze the data to identify areas for improvement and optimize the program for better outcomes. This can lead to a more successful and productive workforce.

There you have it, our selection of hiring trends to look out for in 2020. This isn’t an exhaustive list but we hope it gives a direction to your hiring plans for the upcoming year. Happy hiring!



Popular posts like this:

1. 5 must-have proctoring tips for a developer assessment platform
2. 5 reasons you should use tech recruitment software
3. 6 steps to create a detailed recruiting budget