Leon is available for hire
Hire LeonLeon Redžić
Verified Expert in Engineering
Full-stack Web Developer
Sisak, Croatia
Toptal member since January 12, 2022
Bio
Leon is an ambitious developer with lots of experience in developing a wide variety of applications. Throughout his career, he's contributed to setting the proper groundwork for developing and maintaining web-based applications. With expertise spanning the fintech sector, government contracting, IoT startups, and the fast-paced environment of agency life, Leon's passion and ambition for the industry keep him ahead of the curve and a valuable team member.
Portfolio
Porsche Digital Croatia
Java, Spring, Spring Boot, Apache Kafka, Amazon DynamoDB, REST, Splunk...
Gorilly Digital
Agile Software Development, Java, .NET Core, Angular, React, SQL, Spring...
Erste&Steiermärkische Bank
React, Agile, Azure DevOps, .NET Core, Splunk, SQL, Postman
Experience
- REST APIs - 6 years
- Angular - 5 years
- JavaScript - 5 years
- Java - 4 years
- Laravel - 4 years
- Spring Boot - 3 years
- .NET Core - 3 years
- React - 2 years
Availability
Part-time
Preferred Environment
Git, Visual Studio Code (VS Code), Slack
The most amazing...
...experience I've had in my career is a government contract for which I developed a high-load, high-performance voting platform to choose a 1€ motive for Croatia.
Work Experience
Back-end Developer
2022 - PRESENT
Porsche Digital Croatia
- Collaborated with Formula E and LMDh Porsche factory teams to provide real-time telemetry and cable data to race engineers. Maintained and improved a data platform for telemetry data during WEC, ABB FIA Formula E, and IMSA races.
- Mentored a team of developers to introduce them to the Scaled Agile Framework (SAFe) and back-end development.
- Discussed and contributed to overall project architecture and external tool usage.
- Developed Porsche car renting application for official worldwide Porsche centers.
- Tracked and fixed bugs using the Jira bug tracking tool.
- Worked within SAFe to gain more profound knowledge of how Agile is supposed to be.
Technologies: Java, Spring, Spring Boot, Apache Kafka, Amazon DynamoDB, REST, Splunk, PostgreSQL, Amazon Web Services (AWS), Scaled Agile Framework (SAFe), Azure, Python, Terraform, Azure DevOps, DevOps
Owner
2020 - PRESENT
Gorilly Digital
- Handled a team of developers to build web-based projects using modern technologies, including .NET Core and React.
- Created a voting and proposal platform for the Croatian National Bank to transition Croatia to the Euro currency. The project was built using Laravel that was load-balanced and hooked up to a replicated PostgreSQL database.
- Wrote unit and functional tests to reduce bug regression while developing new features.
- Released a music listening mobile application for the Croatian Music Channel built with React Native.
- Created high-fidelity prototypes for the Nature Park Biokovo that were used to develop an application to teach children about the diversity and history of the nature park itself through gamification.
- Taught programming introduction classes in my community to provide beginners a fighting chance in starting a career in IT.
- Built the architecture for a functional testing project using a BDD approach with the Cucumber testing tool to introduce a shared language that enhances the communication between the tech team and the management.
Technologies: Agile Software Development, Java, .NET Core, Angular, React, SQL, Spring, Spring Boot, NGINX, Unix, Azure, Azure DevOps, PostgreSQL, Automated Testing, React Native, TypeScript
Software Developer
2020 - 2022
Erste&Steiermärkische Bank
- Developed a unified application for contract signing with PKI used by bank customers to sign everything from loan contracts to investments.
- Created a video identification platform that uses OCR to provide the call agents with specific information on client ID cards and save customers a trip to the bank.
- Built a high-load loan application used by clients to receive a loan in a fully online process focused on reducing the amount of paperwork and information necessary to be approved for a cash loan.
- Implemented a bank account opening experience that included both online video identification and online contract signing, saving clients time and money to the bank.
- Used React extensively to develop and test robust applications tasked with providing a quarter of a million clients with valuable products.
- Created an investment platform used for the first time and experienced investors to purchase, sell, and monitor their investments in investment funds.
- Used Postman to test complex test scenarios on REST APIs with the benefit of saving QA testers' time.
- Developed internal tools using Node.js and Express.js to significantly increase the speed of regression testing and provide the marketing department with an easy-to-use mailing platform for the onboarding process.
- Determined the architecture and development process of cross-functional teams for a robust banking application API.
- Involved in product development from the idea phase to the product maintenance phase.
Technologies: React, Agile, Azure DevOps, .NET Core, Splunk, SQL, Postman
Software Developer
2019 - 2020
Nidavellir
- Owned a small business that employed up to three people to develop web-based applications and static websites using Laravel and Vue.js.
- Developed a GIS application for the Croatian government to maintain and track Croatian borders using Java, Angular, and PostGIS as the primary tools for the job.
- Created a caching and delayed synchronization system that provided the Croatian border control to use the application in remote and no internet access areas to retroactively update border data using JavaScript service workers.
- Built and maintained a Laravel application for tourists to find and book a guided tour service. The application is on a partner approval system in which tour guides need to apply for a partnership and be approved by a Croatian travel agency.
- Collaborated with an international and geographically dislocated team with diverse roles in the project.
- Created a flexible reservation system that supports daily booking and a range from minutes to weeks with the UX as the priority.
- Developed a real-time messaging system to provide a tour guide to customer communications regarding meetup location and time.
- Set up a CI/CD pipeline from scratch on a UNIX machine using GitHub Actions.
- Taught software principles and best practices to agency software developers to help standardize and improve the overall quality of code.
Technologies: Agile Software Development, Java, Angular, PostGIS, PostgreSQL, SQL, Spring, Spring Boot, Apache Tomcat, Unix, React, Laravel, Jira
Software Developer
2017 - 2019
EuroArt93
- Worked in a fast-paced environment to develop user-focused applications using modern web technologies like Angular, Vue, React, Ionic, C#, and PHP.
- Managed a team of three members to develop a white-label IoT application using Angular and TypeScript for smart home control using Agile software development methods.
- Used WebSocket technology to provide the user with real-time state of smart home devices that utilize the ZigBee, Z-wave, Bluetooth, and wifi communication protocols.
- Wrote Angular code using software design patterns while incorporating popular libraries like RxJS and TypeScript.
- Took the lead in writing maintainable and reusable JavaScript code for new features to Angular applications using tried and accurate software design patterns.
- Handled application release procedures to the App Store and Play Store, from the initial release to a structured and formalized maintenance release procedure.
- Refactored legacy JavaScript code, improving crucial business processes in speed and quality of results for smart home automation.
- Created a gamified real-time quiz application using Firebase and Vue.js for elementary and high-school students to test their knowledge in collaboration with Algebra University College.
- Developed multiple eCommerce websites using PHP and MySQL to integrate Croatian and international payment gateways.
- Maintained and set up Unix server environments for reseller purposes.
Technologies: PHP, JavaScript, Angular, Vue, Ionic, Yii, Firebase, MySQL, Database Design, Git, Unix, Linux Administration, Linux Server Administration, Agile Software Development, REST APIs, C#, TypeScript
Software Developer
2017 - 2017
NTH Media
- Created an analytics dashboard with real-time data usage using the Java tech stack and Kendo UI with the user interface functionalities developed using Angular.
- Worked with the marketing department on creating the tools necessary for predicting user response and bounce rates.
- Collaborated with the finance department on creating the tools necessary for monitoring and limiting user service spending.
Technologies: Java, Kendo MVC, Kendo UI, Analytics, Angular, Slack, MySQL, JUnit, Git
Freelance Software Developer
2015 - 2017
Self-employed
- Developed a Java web application chatbot used by multiple web stores providing customers with helpful information and shop owners with customer needs.
- Automated scraping using .NET of multiple web marketplaces to provide an up-and-coming store valuable data on their direct competitors.
- Handled deployment and maintenance on all created applications to own or customer UNIX infrastructure.
- Started the long journey of client-focused communication steady on listening to customer needs.
- Formed a passion for 3D graphics development on websites while developing 3D rotating cubes for a client.
Technologies: Java, .NET, Angular, OAuth
Experience
George Store
https://www.erstebank.hr/hr/georgeA mobile banking solution for Erste & Steiermaerkische bank used by a quarter of a million clients.
I was the developer in an agile product team tasked with creating products for the George platform on the Croatian market.
I was the developer in an agile product team tasked with creating products for the George platform on the Croatian market.
Marzito
A Laravel-based application for approved tour guides to offer their services, allowing clients to book and organize a meetup with the tour guide.
During this project, I built a complex, maintainable, and reusable reservation system with multiple time slots in mind.
During this project, I built a complex, maintainable, and reusable reservation system with multiple time slots in mind.
Euro HNB
I developed and maintained a Laravel back-end system that supports voting and abuse protection for a voting platform created for the Croatian National Bank used to vote for the 1€ motive in Croatia's transition from the Croatian Kuna to the Euro currency.
Over half a million people used the project throughout a week—for that purpose, it was load balanced and robust enough to cope with the load.
Over half a million people used the project throughout a week—for that purpose, it was load balanced and robust enough to cope with the load.
Porsche Drive
https://customer.drive.porsche.com/A large-scale application used to rent Porsche vehicles worldwide. Includes building the whole Porsche rental platform used by customers, dealers, agents, accounting, business, and developers, and tools like fleet management and financial reports.
I led a team of back-end developers to maximize their productivity and remove impediments while also adhering to the best practices and architecture of the Porsche platform. When I arrived, the application was in the MVP state and needed improvement in UX and application tooling, and that was the first thing we tackled as a team. After that, we started and are still onboarding new markets and use cases of the fleet management platform.
I led a team of back-end developers to maximize their productivity and remove impediments while also adhering to the best practices and architecture of the Porsche platform. When I arrived, the application was in the MVP state and needed improvement in UX and application tooling, and that was the first thing we tackled as a team. After that, we started and are still onboarding new markets and use cases of the fleet management platform.
Education
2014 - 2017
Bachelor's Degree in Computer Science
Faculty of Organization and Informatics - Varaždin, Croatia
Certifications
JULY 2018 - PRESENT
MTA 98-361: Software Development Fundamentals (C#)
Microsoft
JULY 2016 - PRESENT
MTA 98-349: Windows Operating System Fundamentals
Microsoft
Skills
Libraries/APIs
REST APIs, jQuery, Vue, React, Node.js
Tools
Git, Slack, NGINX, Splunk, Postman, Apache Tomcat, Jira, Amazon EKS, Adyen Payments, Terraform
Languages
JavaScript, TypeScript, C#, Java, PHP, SQL, Python
Frameworks
Angular, Ionic, Laravel, .NET, Spring, Spring Boot, .NET Core, Scaled Agile Framework (SAFe), Kendo MVC, Kendo UI, Yii, JUnit, React Native
Paradigms
Agile Software Development, Database Design, Agile, Azure DevOps, Automated Testing, Load Testing, REST, DevOps
Platforms
Visual Studio Code (VS Code), Windows, Firebase, Unix, Azure, Apache Kafka, Amazon Web Services (AWS), Voucherify, Contentful
Storage
MySQL, PSQL, PostGIS, PostgreSQL, Amazon DynamoDB
Other
Time Management, Analytics, OAuth, Linux Administration, Linux Server Administration, RSS Feeds
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