DSA Crash Course [Part 12] - Pair Sum Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *pair_sum*, that takes in a list and a target sum as arguments. The function should return a tuple containing a pair of indices whose elements sum to the given target. The indices returned must be unique.
>
> Be sure to return the indices, not the elements themselves.
>
> There is guaranteed to be one such pair that sums to the target.

```
pair_sum([3, 2, 5, 4, 1], 8) # -> (0, 2)
```

```
pair_sum([4, 7, 9, 2, 5, 1], 5) # -> (0, 5)
```

```
pair_sum([4, 7, 9, 2, 5, 1], 3) # -> (3, 5)
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 11] - Most Frequent Char Walkthrough

In this lesson, Alvin walks through the python implementation for the *most_frequent_char* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/most-frequent-char?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 10] - Most Frequent Char Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *most_frequent_char*, that takes in a string as an argument. The function should return the most frequent character of the string. If there are ties, return the character that appears earlier in the string.
>
> You can assume that the input string is non-empty.

```
most_frequent_char('bookeeper') # -> 'e'
```

```
most_frequent_char('david') # -> 'd'
```

```
most_frequent_char('abby') # -> 'b'
```

```
most_frequent_char('mississippi') # -> 'i'
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 9] - Anagrams Walkthrough

In this lesson, Alvin walks through the python implementation for the *anagrams* problem.

Code along and test your work in the following editor workspace <https://structy.net/problems/anagrams?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 8] - Anagrams Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *anagrams*, that takes in two strings as arguments. The function should return a boolean indicating whether or not the strings are anagrams. Anagrams are strings that contain the same characters, but in any order.

```
anagrams('restful', 'fluster') # -> True
```

```
anagrams('cats', 'tocs') # -> False
```

```
anagrams('monkeyswrite', 'newyorktimes') # -> True
```

```
anagrams('paper', 'reapa') # -> False
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 7] - Big-O Examples Lecture

In this lecture, Alvin shows examples of code with different Big-O complexities.

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 6] - Big-O Basics Lecture

In this lecture, Alvin goes over the basics of Big-O notation and how to use it to describe the complexity of algorithms.

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 5] - Is Prime Walkthrough

In this lesson, Alvin walks through the python implementation for the *is_prime* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/is-prime?language=py>

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 4] - Is Prime Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *is_prime*, that takes in a number as an argument. The function should return a boolean indicating whether or not the given number is prime.
>
> A prime number is a number that is only divisible by two distinct numbers: 1 and itself.
>
> For example, 7 is a prime because it is only divisible by 1 and 7. For example, 6 is not a prime because it is divisible by 1, 2, 3, and 6.
>
> You can assume that the input number is a positive integer.

```
is_prime(2) # -> True
```

```
is_prime(3) # -> True
```

```
is_prime(4) # -> False
```

```
is_prime(5) # -> True
```

```
is_prime(6) # -> False
```

```
is_prime(7) # -> True
```

```
is_prime(8) # -> False
```

```
is_prime(2017) # -> True
```

```
is_prime(2048) # -> False
```

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 3] - Max Value Walkthrough

In this lesson, Alvin walks through the python implementation for the *max_value* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/max-value?language=py>

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 2] - Max Value Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *max_value*, that takes in a list of numbers as an argument. The function should return the largest number in the list.\
> \
> Solve this without using any built-in list methods.\
> \
> You can assume that the list is non-empty.

```
max_value([4, 7, 2, 8, 10, 9]) # -> 10
```

```
max_value([10, 5, 40, 40.3]) # -> 40.3
```

```
max_value([-5, -2, -1, -11]) # -> -1
```

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 1] - Course Welcome

Welcome to our crash course for data structures and algorithms! This incredibly in-depth course will help you master core data structures and algorithms concepts, even if you're a complete beginner with the topic. This course is exactly for you if:

- You want to be efficient with your study time
- You don't enjoy solely grinding LeetCode because it's slow and frustrating
- You want to actually understand the concepts instead of merely memorizing patterns

This course is special because it's carefully engineered to be a smooth and effective ride:

- Problems are specifically chosen to be a progressive sequence, building on top of one another
- The overall difficulty of the problems you'll solve will gradually increase
- You will be able to visualize the underlying data structures and algorithms with animated explanations
- Learn the implementation with concrete code walkthroughs

If you need additional support taking these DSA skills and actually applying them, take [Alvin's](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [Structy](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [this link to get 20% off](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

How to Crack System Design Interviews - Part 11: Conclusion

This concludes the System Design Interview course! To maximize your performance in upcoming interviews, we recommend:

- **Reviewing the course content:** Shortly before your interview, revisit the course material and use it as a checklist to ensure you've grasped the key concepts.

- **Focusing on communication:** Remember that the interview assesses your ability to communicate effectively, demonstrate knowledge of existing systems, and showcase problem-solving skills.

- **Practicing and preparing:** Thorough preparation is crucial for success in system design interviews. Utilize the resources and strategies discussed throughout the course to enhance your skills and increase your confidence.

- **Remembering your value:** Regardless of the interview outcome, your competence and skills as an engineer remain valuable.

Good luck with your interviews!

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 10: Preparation Resources

This video outlines resources and strategies to prepare for system design interviews. We can improve our performance by:

- **Building a strong vocabulary:** Familiarizing ourselves with key technologies and concepts (e.g., Amazon S3, Apache Kafka) helps us communicate ideas effectively and demonstrate practical understanding.

- **Developing theoretical knowledge:** We can gain a solid theoretical foundation through courses like Interview Ready, which covers high-level and low-level design concepts, design trade-offs, and other essential topics.

- **Gaining practical experience:** Mock interviews provide invaluable practice and build confidence for the real interview. Consider using free platforms or seeking discounts if available.

- **Utilizing online assessment tools:** If time is limited, leverage automated online judges to assess and reinforce understanding of system design components and their placement.

- **Prioritizing human interaction:** While online tools are helpful, prioritize mock interviews with experienced individuals for the most effective preparation and feedback.

A few tools mentioned: 

- Mock Interviews: [joinTaro.com/perks](https://www.jointaro.com/perks/)
- [Automated Design Judge](https://interviewready.io/question-list/system-design-judge/?_aff=JOINTARO)
- [General Resources for SD](https://interviewready.io/resources)

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 9: Effective Communication

This video details the scoring criteria for system design interviews, focusing on scalability, reliability, and communication. We learn how to demonstrate strong technical skills and cultural fit:

- **Identify and mitigate bottlenecks:** We should proactively identify scalability and performance bottlenecks in our design and propose effective mitigation strategies.

- **Address potential failures:** We must analyze potential points of failure, including those in external systems, and explain how we would handle them.

- **Communicate clearly and effectively:** We need to present our solution in a structured and organized manner, using appropriate terminology and incorporating feedback constructively.

- **Demonstrate cultural fit:** We should align our design choices and communication style with the company's values and priorities, showcasing our understanding of their engineering culture.

- **Maintain professionalism:** We must conduct ourselves professionally throughout the interview, avoiding inappropriate jokes or comments and demonstrating openness to feedback.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 8: Technical Competence

This video analyzes the technical aspects of a system design interview, focusing on how our design choices are evaluated. Here's what we need to keep in mind:

- **Thoughtful design choices:** We must justify our technology choices (e.g., Cassandra) with clear reasoning connected to the system's needs and demonstrate awareness of alternative solutions.

- **Multiple solutions and trade-offs:** We should showcase our technical depth by considering various solutions (e.g., push vs. pull models) and understanding their trade-offs (e.g., SQL vs. NoSQL databases).

- **Real-world examples:** We need to incorporate practical, real-world examples of technologies and products to illustrate our design choices and demonstrate practicality.

- **Deep technical knowledge:** We should possess a strong understanding of the technologies we propose, including their internal workings and how they compare to alternatives.

- **Feedback and iteration:** We must be receptive to feedback on our design choices and demonstrate the ability to adapt and improve our solutions based on the interviewer's input.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 7: System Design Scorecard

This video explains how candidates are evaluated and scored in system design interviews at large tech companies. We learn about the scorecard used to assess performance across five key parameters:

- **Problem Scope:** This includes listing and clarifying product requirements, discussing user interactions and expectations, and considering system scale.

- **Technical Design:** This involves making appropriate design choices, leveraging design patterns, and demonstrating knowledge of relevant technologies.

- **Scalability:** This encompasses designing a system that can handle increasing amounts of data and traffic.

- **Reliability:** This involves ensuring the system is fault-tolerant and can handle failures gracefully.

- **Communication:** This includes effectively conveying ideas, actively listening to the interviewer, and incorporating feedback.

Each parameter is scored from 0 to 5, with a total score ranging from 0 to 25. A higher score indicates a stronger candidate, and the acceptable score range varies depending on the target seniority level.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 6: Mock Interview

This video demonstrates a system design interview for analyzing Snapchat filter usage. We are tasked with designing a system to track and analyze filter usage data for executives and product managers. Here's what we do:

- **Gather requirements:** We clarify the scope of the system, including the number of filters, their dynamic nature, and the desired metrics (daily, weekly, monthly usage, and potentially hourly breakdowns).

- **Design the system:** We propose a write-heavy system with separate read and write paths to optimize performance. The write path handles incoming events from users, while the read path aggregates and transforms data for querying.

- **Consider scalability:** We discuss sharding and using a write-optimized database like Cassandra to handle the high volume of incoming events.

- **Address data aggregation:** We explore using Apache Spark to process and aggregate data based on time and user demographics, storing the results in a database like DynamoDB.

- **Differentiate query types:** We propose separate APIs for common, pre-aggregated queries and custom queries, acknowledging the potential latency differences between the two.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 5: Reviewing Your Solution

This section of the system design interview focuses on identifying and evaluating trade-offs within the proposed design. Here's how we navigate this:

- **Start with non-functional requirements:** We begin by analyzing how non-functional requirements, such as durability, influence design choices and user experience.
- **Analyze access patterns:** We consider how users interact with the system, examining the frequency of different requests and their impact on optimization strategies.
- **Make conscious trade-offs:** Based on our analysis, we make deliberate trade-offs, such as potentially sacrificing immediate consistency for faster read operations.
- **Use precise language:** We use clear and established engineering terms to facilitate accurate communication and efficient use of interview time.
- **Remain adaptable:** We stay open to feedback from the interviewer and adjust our design based on their input, acknowledging their understanding of the system.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

How to Crack System Design Interviews - Part 4: Choosing Design Tradeoffs

When discussing design trade-offs in a system design interview, it's important to go beyond simply reciting known trade-offs. Instead, we take a more analytical approach:

- **Consider non-functional requirements:** We examine the impact of non-functional requirements, such as durability guarantees, on the system design and user experience.

- **Analyze access patterns:** We study how users interact with the system, considering the frequency of different API calls and their implications for optimization.

- **Make informed decisions:** Based on our analysis, we make conscious trade-offs, such as prioritizing read performance over immediate data consistency.

- **Use standard terminology:** We employ clear and concise engineering terms to ensure accurate communication and efficient use of interview time.

- **Be open to feedback:** We remain flexible and adjust our assumptions based on feedback from the interviewer, recognizing their expertise and knowledge of the system.

[Gaurav Sen](https://www.linkedin.com/in/gkcs/) has conducted 1000s of system design interviews while working at Uber and building his [YouTube channel](https://www.youtube.com/@gkcs) to 500K+ subscribers. His platform [InterviewReady](https://interviewready.io/?_aff=JOINTARO) combines video explainers, live Zoom classes, and an automated System Design Judge.

Tech Career Growth Videos

Our instructional videos provide software engineers with insights needed for career growth. Masterclasses go incredibly in-depth on a specific tech topic while case studies are real examples from established engineering leaders.