Saša Šijak

Implemented high traffic public-facing websites for the most popular app which connects classrooms with parents and engage kids: Classdojo.

The website was previously built with older technology and was in a need of a complete rewrite. I've implemented the website with React, GatsbyJS, and Styled System.

Besides the main websites, I implemented other public-facing sites ideas.classdojo.com and blog.classdojo.com.

I implemented a website that was featured on Adidas' homepage and is a heavily marketed campaign for sports coaches to teach them how to approach and keep girls in sport.

As the sole developer, I built the website using React/Gatsby along with implementing the custom styling and design.

I designed and implemented the back-end for the online casino management system. This system was later used on many websites and had tens of thousands of users. It was very flexible and offered some crucial features that competitors did not have. It made a good profit for the clients and is still used today on many websites.

Technologies: Python, ZeroMQ, MySQL, SQLAlchemy, Redis, Linux

Developed a website to sell beautiful and responsive UI blocks made with ChakraUI and Framer Motion with code export to NextJS or GatsbyJS.

Built hundreds of ready-to-use blocks and drag and drop builder to quickly build pages and preview them.

I built it from scratch and did everything from developing it to marketing, sales, deployments, and support.

Created a website that serves a purpose of a digital will and as a protection of digital assets like crypto assets.

It is a digital version of a physical switch that is designed to be activated or deactivated if the human operator becomes incapacitated, such as through death, loss of consciousness or being bodily removed from control.

User can create switches, and configure how often should service check-up on them, over which channel (email or SMS) and if they become unavailable it sends their predefined messages.

Public-facing website for a school build with GatsbyJS and backed by a headless CMS Contentful.

I did not build the site from scratch. I inherited the project at some point because the client was not happy with the previous agency and I am now the sole developer on this website for more than a year.

I led the design and implementation of a land-based casino management system which was used in the largest betting operator in Southeastern Europe. It is used in several countries to manage more than 500 betting shops and more than 3,000 gambling machines in real-time. It is used to manage everything from machine information to jackpots and everything going-on in real-time. It was presented with large success at the London ICE Totally Gaming fair.

Technologies: Java, Spring Framework, AngularJS, Oracle Database, Redis, Linux, ActiveMQ

I implemented a messaging system; this included both the back and front end along with an integration with the rest of the system. This enabled our managers to interact with players and customers. It also sends automated messages to customers when relevant events occur.

Technologies: Java, Spring, Vue.js, ActiveMQ, Oracle, Linux

I implemented a large part of the betting machine/terminal project. These machines are placed in betting shops or cafes. It involved working with the hardware approval process, integrating several hardware products, making an API and integration with the rest of the system, deployment system to several hundred machines on random locations, server and machine administration, and so on.

Technologies: Java, Spring, Vue.js, ActiveMQ, SQLite, Oracle, Linux

With a colleague, we implemented a first-of-its-kind jackpot system used with roulette in land-based casinos in our business region of interest.

Technologies: Java, Spring, ActiveMQ, Oracle, Linux

I worked with a team to create a multiplayer turn-based soccer game which was played by tens of thousands of players and attracted investors.

Technologies: Java, JavaScript, Vert.x

I hacked the proprietary protocol for communication with gambling machines by sniffing the traffic with modified serial cables and traffic analysis. Later, I wrote the server which implemented that protocol and which is successfully in use today.

I set up the website, Facebook page, Instagram account, the brand's whole online presence, SEO and marketing campaigns for a personal trainer's business. At first, the website was created with WordPress because of the very high deadline pressure and later I rewrote it in GatsbyJS (a React and GraphQL-based static site generator) and hosted it on Netlify. There is also a protected part of the website which is using Firebase Auth and Firestore.

Technologies: React, GatsbyJS, Firebase, WordPress, Contentful, Netlify

I needed to find a flat (apartment) to rent and 90% of the ads on the internet were from the really bad agencies—I spent a month trying to manually find a flat.

To solve this, I wrote a program that scrapes websites with flat ads every few hours, filters out all the agency and fishy ads, and showed me all good ones in the part of the city and other parameters that I was interested in.

In the end, I found a flat in one day. I used this program again two years later and had the same result—I also found a flat in one day. Then I decided to share it with friends.

Technologies: Java

I tested various earning methods on Google Play (Google Market before the switch), marketing strategies, and app positioning in the search results. The app earns a very good dollar return per hour due to the applied techniques.

Technologies: Java, Android