Ivan Nikolov's Blog

Why I Will Never Rent a Car With Europcar Again

This will be a very different post from what I normally put on this blog, but I decided to write it for a few reasons. I was very disappointed with my last experience with Europcar. I feel like writing this down will flush this out of my head and I can stop thinking and being annoyed about it. Finally I am hoping this will be useful to someone out there and maybe will make the company improve how they do business in future. Possibly another company will read this and improve their systems. While I’m writing about services, some of the topics I am about to cover aren’t too far from the topics I cover in my blog – mainly software.

Improve Graphite Performance using Go-Carbon

In this blog post I would like to share my experience with using go-carbon to get better performance out of our monitoring system.

Coronavirus: Working from Home

The new Coronavirus has made governments across Europe and the rest of the world take some pretty extreme measures in order to handle the spread of the virus. Regardless of whether you support your government’s decisions or not, if you are one of the more fortunate people who can still continue working from home, you will be most likely required to do so.

The N-Queens Problem in Scala

Recently at my office I had a discussion about algorithms and the N-Queens problem came up. I didn’t know about it, so I decided to check it out and then I felt like I wanted to write an implementation in Scala. This blog post documents all of this.

Spark Caching – RDD vs Dataset

Apache Spark (https://spark.apache.org/) is one of the most popular analytics engines used nowadays. It has been around since 2009 and one of the reasons it became so popular is its speed compared to traditional MapReduce and specifically Hadoop, which it was inspired by.

Smallest Enclosing Circle Algorithm in Scala

In the last couple of years I have been using the Scala programming language for a large chunk of projects at work. I use it to write batch processing jobs with Spark, APIs using the Play Framework, different Akka programs as well as apps and tools. I’ve even written a book about design patterns in Scala in 2 editions.

Scala is an awesome programming language and I enjoy using it. It is very quick to write complex and efficient code. Of course, if you’re not careful or familiar enough with the language you might pay some price in terms of efficiency, but any programming language is like that. It is a multi-paradigm language that combines object-oriented and functional programming. It runs on the JVM and in theory it is compatible with Java and Java bytecode. And it practically is in most cases.

Algorithms: Sorting – Heap Sort

Before we start discussing the topic of this post, we need to point out how important sorting actually is. Almost every problem that one will face in computer science can be solved with sorting as an initial phase. That’s why everybody must know a few good sorting techniques and when they can be used.

Let’s not even consider bubble sort and other algorithms with sqr(n) complexity as this is way too much especially with the amounts of data we see nowadays. If someone gets asked a question with sorting on a job interview, please don’t reply bubble sort! Of course, it is good knowing about it, but there are methods, which are much more suitable.

Algorithms and Data Structures – Binary Trees

In this article I will present trees. This is another data structure that is really important in computer science and it can be used to model different relationships between real life objects. It could be also helpful as a data structure for some algorithms and also as a base of other data structures like maps or sets for example (tree maps/tree sets).

Advanced Operations over Linked Lists

This article continues my previous talk about linked lists and basic operations that can be performed with them. If you haven’t read the first part, I recommend you do this at https://www.ivan-nikolov.com/2017/09/01/algorithms-and-data-structures-linked-lists.

Except just inserting, deleting and searching for elements, a linked list can be reversed, it can have a different sctucture, it can be maintained sorted, etc.

Algorithms and Data Structures – Linked Lists

Before I even start talking about linked lists in this post, I would like to strongly point out how important algorithms and data structures are. This is something a software engineer uses literally 100% of the time, even if we are talking about the simplest possible task. It is essential for someone to understand what algorithm complexity means and how it can affect their code and more importantly – the quality and the performance of their program.