Sign in

This is a basic introduction of gRPC.

Benefits of gRPC

gRPC uses protocol buffers and HTTP2, which will help the service communications to be much faster, and use less resources.

Protocol Buffers vs JSON

By using protocol buffers, we can achieve faster and more efficient communication, especially for devices with slower CPUs:

  1. Payload Size: To store the same information, JSON object sizes are larger than protocol buffers.
  2. CPU Usage: Parsing JSON is more CPU intensive than paring protocol buffers (as protocol buffers are binaries).


  1. Multiplexing: HTTP2 only needs to open 1 TCP connection, and the connection will remain open after communication is completed.
  2. Server Push: HTTP2 allows…

This is the first tutorial of this series, which covers the basic concepts of Kafka

Basic Concept — Data Topics

  1. Topic: A particular stream of data, identified by the topic name.
  2. Partition: Topic splits into partitions; Each partition is a queue of messages.
  3. Offset: The incremental id assigned to the message in the partition.


  1. Offset guarantees the order of messages in the partition.
  2. Offset (the incremental Id) is only meaningful within the partition (i.e. message with id 2 in partition 1 is not guaranteed to be older than message with id 0 in partition 2).
  3. Message is kept in the partition for a limited time…

In this blog, we will discuss an interview question asked by Google.

In this post, we are going to discuss the leetcode problem no. 1055 — Shortest Way to Form String, which is recently asked in Google interviews.

Firstly, we will try to solve the problem with brute force method in O(n²) running time; then we will improve our algorithm to O(n log n) running time; finally we will further improve the algorithm to O(n).

Problem Analysis

The input of the problem is two strings: source and target. …

Recent interview question asked by Google and Amazon.

In this post, we are going to discuss the leetcode problem no. 253 — Meeting Rooms II. This problem is recently asked in Google and Amazon interviews.

Problem Analysis

The input of the problem is a list of meeting schedules. Each meeting schedule is represented by a list of two items, with the first item as the starting time of a meeting, and the second item as the ending time of the meeting.

The expected output of the problem is an integer, which is the minimum number of meeting rooms required to fulfill…

This is an introduction to dynamic array and its implementation

An array is a contiguous area of memory of equal-size elements. Array length is usually fixed, which means you need to specify the number of elements your array can hold ahead of time.

A dynamic array is an array which has an important feature: auto-resizing. With this feature, you can easily expand your array by adding more elements in it, so that you do not need to determine the size ahead of time.

In this tutorial, we will discuss about the implementation of dynamic array by using regular fixed length…

In this post, I will discuss details about Gradient Descent and Back-propagation in neural networks, and will help you to understand why there is Vanishing Gradient Problem. In my earlier post (How to implement Gradient Descent in Python), I discussed python implementation of Gradient Descent. In this post, I will show you step-by-step to understand the math behind the Neural Networks.


For the Neural Networks discussed in the post, we will make the following assumptions:

  • Sigmoid Function is used as the activation function
Sigmoid Function

Gradient Descent is the most important concept in Neural Networks. In this tutorial, I am going to show you how to implement it in Python. I hope this tutorial can help you to build a better understanding about how gradient descent works, and how it helps to improve model accuracy.

Data Pre-Processing

We will try to build a single neuron network, which can predict the admissions of a graduate school. The data we will use is shared above in google drive. Let us first take a peek at the raw data:

The first 5 rows of data are shown below. The…

Y Tech

Software Engineer

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store