Source: WhatsApp.com

With over 2 billion users across the globe, WhatsApp messenger has become a household name and the messaging app of choice for many.

These are very impressive numbers that lead to the question: “How does WhatsApp messenger work?”

Background

In a small network, we can easily send each other messages, a perfect example would be me sending a message to my friend Dee Didi. The process is quite easy as we are on the same network and my device knows the IP address of Dee’s device.

The problem starts when I also want to send the same message to Luvo, Langa…


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Computers sort and search in a linear or binary manner. If you are to instruct them to use linear methods, then we do not need to sort our data. Whilst if we want them to approach the matter in a binary manner, the data must be sorted.

Navigating through arrays is the linear method and we do not need to sort our data. We have 3 different types of arrays namely;

  • Lists[]
  • Tuple (, , ,)
  • String (“”)

Let's cover the first half of our interview questions:

Check If String IsUnique

We are asked to write an algorithm to check if a string has…


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What comes to mind when you think of Uber? The tech giant that revolutionized the taxi industry? A company that was inspired by a James Bond movie or convenience!

Yes you heard me, Uber was inspired by the James Bond movie Casino Royal.

One of the founders of Uber Garrett Camp was very frustrated with the Taxi service, and one day while watching Casino Royal, he noticed James bond use a cellphone to track the location of a car. …


Algorithms are like art; they should also be analyzed in an artistic manner.

  • How long will an algorithm take to compute
  • How much space will it take to run the algorithm
  • Network and data transfer needed for the algorithm
  • Power Consumption needed to run the algorithm.

At a basic level, we will only look at the time and space complexity

There are two methods commonly used to find the Time and Space Complexity of an Algorithm. Namely “ The Frequency Method” and “Assymptotic Notation”.

In this article, we will be diving into The Frequency Method.

Source: Joshua Earle via Unsplash.com

What is Frequency Count?

This is basically the number…


A very popular interview question that tests your knowledge in producing efficient code. Ideally, there are two approaches to solving this popular question.

Source: Kai Wenzel via Unsplash.com

We are given a list of numbers together with the target number and are expected to figure out which two numbers add to the target. The combination of numbers could or could not exist.

The question could be structured as follows;

“ Suppose we have an array of integers. We have to return the indices of two integers, such that if we add them up, we will reach a specific target that is also given. …


If I was a hot shot head chef at a world class restaurant, I would use “The chicken test” as a litmus test for hiring chefs.

I would ask them to cook me chicken! Why chicken you may ask?

If a chef cannot cook chicken and make it tasty, then they probably are not ready to cook world class meals

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Same is applicable to a software engineer, if they cannot code the simple kids game of Fizz Buzz then, they are probably not ready to produce world class software!

So what is Fizz Buzz?

Fizz Buzz is a kids game…


We have to appreciate the sophisticated interface development programs we use today. When we look at the developers/mathematicians that came before us, they didn’t have error detecting IDE’S.

Source: NASA

Coding errors are expensive, various institutions are a victim to theses and The National Aeronautics and Space Administration is no acceptation.

Time to go back to 1962 where a simple coding error cost NASA $18.5 million, which amounts to $150 million on present-day estimates.

The Marina 1 was built to conduct the first planetary flyby of Venus, it was launched by an Atlas -Agena rocket from Cape Canaveral. …


We interact with our devices more than we do with our partners, they are our companions. We are manipulated and exploited by algorithms that run these devices, the algorithms are top employees to Big Tech companies!

The companies are more interested in our data, this data is either sold off in aggregate to other companies or used to design predictive models and problem-solving models.

As the saying goes; “Data is the new oil” or is it?

Source: Gian Cescon via Unsplash.com

Should we treat data as a commodity, is it even our data to begin with or is it just information generated within the information…


As a society, we were never prepared for the previous industrial revolutions, this could be the reason for the inequality gaps and poverty in our society. We need to prepare for the 4th industrial revolution.

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We are witnessing the beginning of the 4th industrial revolution, often referred to as “The Robot Apocalypse”. Instead of demonizing and fearing the technology revolution, let’s rather plan and prepare for it.

Globally an increasing number of companies are adopting and utilizing robotics, artificial intelligence, and automation to fast track production.

This is ideal for them as a robot does not fall ill, no need…


Source: Andy Kelly via Unsplash.com

1. Mathematics

I started off learning mathematics before code, there are various applications of mathematics. Particularly Applied Mathematics which led me to computer science, and most recently machine learning.

To deeply understand machine learning to the core a mathematics foundation is needed specifically; calculus, linear algebra, probability theory, discrete mathematics and statistics.

The library route of designing models is ok at first but not feasible as you need to understand what happens below the bonnet. This is effective if you want to tweak models that have been pre built for custom needs.

Example l1 and l2 lasso regression use different mathematical equations…

Thenjiwe kubheka

Software Engineer, Mathematics, Artificial Intelligence

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