Mladen Čikara

Dextcloud is a low-code development platform that aims to help users develop REST APIs with minimal code required.

I was a back-end developer in a small team of five people. I was mainly working on developing back-end features and working very closely with front-end team members to connect the back end and front end and with operations team members to help with the CI/CD pipeline. We used microservice architecture and Kubernetes to allow the application to run on AWS, GCP, and OpenShift. I was involved in deploying the application to a banking client: the app was in production use for more than a year there. As this platform allows developing a wide range of APIs, I was fortunate to work with a large number of interesting services, e.g., AWS, GCP, Kubernetes, the Stripe API, Auth0, Amazon Cognito, Okta, HashiCorp Vault, MongoDB, Kafka, Salesforce to name a few. I also ran daily stand-ups and scrum evens after the scrum master left the team, so I was closely involved in backlog grooming and feature planning.

Datagama is an application for gamifying surveys to make them more engaging for end users.

My tasks were to improve the existing application by connecting it to Stripe and enabling monetization. I was also working on improving existing games in jQuery and adding new games. The back end was done with Spring and Java, and I had to add features so that further improvements from games would be saved and processed.

CPM is an application for gathering all required data from bank clients and calculating all documents that need to be received to prove the gathered data. CPM is used by all bank (Zagrebačka Banka) employees who are working with clients in all 97 Croatian offices.

I worked as a senior software developer for the back-end part of the application. I worked very closely with the front-end team to create a REST API that minimizes the number of requests from front to back. I also worked on processing incoming data and storing them in Elasticsearch for quicker and more flexible queries. I worked on creating optimized SQL queries and PL/SQL procedures with the database team.

We used domain-driven design for modeling applications and scrum for project management.

LCS is a set of tools and services for managing and monitoring Liferay instances. It helps users manage Liferay clusters by installing fix packs, monitor performances, and manage subscriptions. LCS is separated into two parts. The back end gathers and processes data and a Liferay plugin that is installed on Liferay Portal instances. We built the back end with microservices architecture and deployed it in AWS.

I worked as a software developer on both parts but mainly on the back end. In addition to Java programming, I was tasked with writing the Ansible script that automated deployment to AWS.

I also managed ELK (Elasticsearch, Logstash, Kibana) for gathering and classifying all logs from all services in one place.

Identalia CRM is a custom-made CRM system for tracking dental patients from initial contact until all medical procedures are done. It has three distinct parts. The first is for managing a call center where all contact client data is stored and presented to the operator. The second part is for managing medical patients' stay in the clinic, where doctors and nurses could enter all procedures that were done. The third part was meant to manage medical supplies.

While working for Polyclinic Identalia, I helped develop a CRM application. I worked as a developer in a small team with two other developers. That is why I was involved in every aspect of making the application.

Despite having a small team, we made an application that connected telephone switches and routed incoming and outgoing calls to relevant call operators in our CRM application. We also connected our application to a third-party ERP system.

We provided support for applications and worked very closely with our users. That enabled us to focus our development on features that brought the most business value.

I was the architect and lead developer for an application for managing the sales of mutual and retirement funds for NLB (Nlb.si). I served as the team lead for a team of three people. This application recorded prices and quantities of shares and calculated provisions awarded to the company's sales force. The application was developed with Vaadin and Spring.

Cash Money Tracking System is an application that IN2 developed for FinaGS (www.finags.hr). FinaGS is Croatia's largest company for storing, transporting, and distributing cash and securities.

In this project, I started as a software developer, but I was promoted to lead developer because the previous lead developer had left the company during the project. We used the BPMN tool ActiveVOS to track all operations of FinaGS. The front end was created with Vaadin, and the back end was created with Spring and deployed to Tomcat servers. We also connected to machines for counting money to record counts and to signature pads to record operators for every operation.

This project involved connecting BrokerIN2 with ORC Trader (Itiviti.com/orc). With this connector, we enabled users of BrokerIN2 to send orders to the stock exchange via the ORC application.

The connector was created in Java and Spring and deployed on the JBoss application server. I used the Financial Information eXchange (FIX) protocol to get data from the market and stored it in our database. In this project, we used enterprise integration patterns (EIP) to connect applications.

BrokerIn2 is an application for the back office of an equity trading company. It manages client personal data, information about buy and sell orders, and executions of said orders. It calculates the fees that the client is charged. All documents required by law are generated in this application.

I worked in a small team of three people as a junior software developer, and we were tasked with creating database models, business logic, user interfaces, and reports. The application was created in PL/SQL using Oracle Designer, Oracle Forms, and Oracle Reports.

ENC Checker is a simple Android application that I created while learning Android development. It checks a balance on an ENC device (electronic toll collection system) for one Croatian ENC provider (HAC).

I try to get a deep understanding of the technologies and tools that I use. For that, I use learning tests and techniques that I have learned from Robert C. Martin (Uncle Bob). I also create tests to learn a language, tool, or framework. The most important tests are those that show how I will be using this technology in a real project, but these tests are a great way to learn the limitations of the tools I'm testing.

These tests are great tools even later when I have a good understanding of the technology because when a new version is released, I can update my build script and check for failing tests.

I believe that sharing knowledge is an important and great way to get a deeper understanding of what you are presenting. It is also a great way to get other perspectives during Q and A. That is why I try to present at the Croatian Java Usergroup conference whenever I can.

A presentation about connecting to ZeroMQ and server-side push to the front end: https://www.slideshare.net/hujak/javacro14-zeromq-and-javascript-mladen-ikara

A presentation about using ELK stack in Liferay Connected Services (LCS): https://2019.javacro.hr/JavaCRO-16/Program/ELK-Stack-Problemi-i-nasa-rjesenja

A presentation about creating simple query language with ANTLR (ANother Tool for Language Recognition): https://2020.javacro.hr/JavaCRO-18/Program/Creating-simple-languages-with-ANTLR

ELM Stopwatch is a simple progressive web application I created while learning about ELM programming language. I used Bootstrap for the presentation.

Repository: https://github.com/McNullty/elm-stopwatch