Using Apache Ignite to Prevent Duplicate REST Requests

I faced a non-unique problem, my API kept getting duplicate requests in rapid succession from time to time. One of those "It works on my machine" issues that I only saw in a production environment and only due to some misbehaving clients. I know APIs are supposed to be stateless and idempotent and all those buzzwords... I had all that and more, however the duplicates kept coming in, causing the need for cleanup scripts and subtle bugs downstream in a large enterprise system.

Software Engineer Vs Programmer

There are different terms that describe the job of someone who creates software, and some such terms carry a type of stigma along with them. Here's my attempt to rant about what I think the difference is between two very popular terms: Software Engineer and Programmer.

Finding Islands In a Binary Matrix

There is a problem that very often tends to pop up in a lot of technical coding interviews because the solution can be trivial if the candidate understands core concepts of computer science such as recursion and depth first search. It also reveals in-depth knowledge of graphs and common graph traversal algorithms. The problem statement is, given an NxN matrix which contains only 0's and 1's find the number of islands within the matrix. An island is defined as adjacent matrix cells containing 1's, where adjacent means horizontal, vertical and diagonal neighbor cells. In this article I present an efficient enough algorithm with O(n) complexity that takes advantage of a depth first search approach to quickly iterate through the matrix and recursively detect islands.

Algebraic Types in Scala???

If you have ever looked into Scala at any point you would’ve heard the term Algebraic Data Types

The goal here is to attempt to explain what that is since it’s kind of an obscure concept from an OO view point. Even though you could draw a parallel between algebraic types and Composition vs Inheritance, it’s not quite the same thing. So it’s worth while to try to understand ADT for what it is.