Hello, my name is
Ionescu Leonard-Octavian
and I am a
Student
I am currently a student of the Master of Computer Science program at the University of Vienna. My educational experiences, both within and beyond the classroom, have nurtured my analytical thinking, problem-solving skills, and a profound understanding of various programming languages and concepts.
I am currently a student in my third semester of the Master of Computer Science program at the University of Vienna. My educational experiences, both within and beyond the classroom, have nurtured my analytical thinking, problem-solving skills, and a profound understanding of various programming languages and concepts.
Skills
Languages
JavaScript
100%
Python
90%
Java
80%
C\C++
80%
HTML
90%
CSS
80%
C#
50%
SQL
50%
Frameworks
React
90%
Android(Java)
80%
Node.js
80%
Express.js
80%
Tailwind
90%
Selenium
100%
Spring
50%
Angular
50%
Tools
Git
80%
Maven
100%
Linux
60%
Firebase
50%
VS Code
90%
Intellij
70%
MongoDB
80%
PostgreSQL
80%
Education
10/2022 - Ongoing – Vienna, Austria
C++ Python Java OpenMP MPI OpenCL
Master in Computer Science - University of Vienna
Studied Subjects:
◦ Foundations of Data Analysis
◦ Parallel Computing
◦ Information Security Management
◦ Network Security
◦ Signal and Image Processing
◦ Parallel Architectures and Programming Models
◦ Praktikum 1: Implemented a public blockchain system
10/2019 – 07/2022 – Bucharest, Romania
C\C++ Java JavaScript C# SQL Linux React Node.js JUnit Android
Bachelor of Economic Informatics – Academy of Economic Studies - Faculty of Cybernetics, Statistics and Economic Informatics
Studied Subjects:
◦ Object-Oriented Programming
◦ Multiparadigm Programming
◦ Algorithms and Programming Techniques
◦ Data Structures
◦ Operating Systems
◦ Web Technologies
◦ Mobile App Development (Android)
◦ Windows App Development
◦ Software Quality and Testing
◦ Databases
Field of study: Economic Informatics
Thesis: The Development of a Business Video Conference Application
Final Grade: 10 out of 10
02/2022 – Bucharest, Romania
International English Language Testing System (IELTS)
Test Results:
◦ Listening: 9.0/9.0 (C2)
◦ Reading: 9.0/9.0 (C2)
◦ Writing: 7.0/9.0 (B2)
◦ Speaking: 8.0/9.0 (C1)
◦ Ovearall Result: 8.5/9.0 (C2)
Experience
03/2021 – 05/2021 – Bucharest, Romania
Angular Spring Selenium JUnit Git Linux
Internship - Software Development – Endava Romania
◦ Actively participated in workshops and training sessions focused on learning how to build both frontend and backend components using Spring Framework and Angular.
◦ Tested various software sequences created by the team to ensure they worked as expected.
◦ Used tools like Selenium and JUnit for testing and reported any issues found to the supervisor.
◦ Gained familiarity with essential Linux commands, which are commonly used in the development environment.
◦ Learned to use Git for version control, a crucial skill for collaboration in software projects.
07/2022 - 09/2022 - Bucharest, Romania
React Tailwind CSS Node.js Express.js MongoDB
Internship - Fullstack Developer - Chess Coders Romania
Frontend Development:
◦ Utilized React to build engaging user interfaces for the website.
◦ Implemented responsive design using Tailwind CSS, ensuring the site looks great on various devices.
◦ Created dynamic components to enhance user interaction and overall experience.
Backend Development:
◦ Developed the server-side using Express.js, handling data requests and interactions.
◦ Designed and integrated a database using MongoDB to store and manage essential data.
◦ Implemented APIs for communication between the frontend and backend, enabling seamless data exchange.
Full-Stack Collaboration:
◦ Gained hands-on experience in the complete software development cycle, from frontend to backend.
◦ Worked collaboratively with the team to ensure smooth integration of frontend and backend components.
◦ Contributed to optimizing the performance and user-friendliness of the web application.
10/2019 – 07/2022 – Bucharest, Romania
Volunteer – SISC (Faculty of Cibernetics Student Union)
Main Responsibilities:
◦ Working within the PR department of the association
◦ Participating to the association board meetings, planning future events and campaigns and dividing tasks
◦ Designing the advertising materials used in promoting our events
◦ Managing the online platforms and web page of the association
◦ Participating alongside other association members to meetings with the university board of directors, discussing our plans and proposals received from the students of our faculty
Portfolio
2022
React Node.js Express.js Socket.io PostgreSQL REST
Business Video Conference Application
Developed a working peer to peer video conference app.
The app allows for the following functionality: creating an account, creating new contacts and adding them to your personal contact list where you can call them at any time, creating video conference rooms, joining a room by accessing its URL, screen sharing.
The app consists of two parts:
◦ frontend application built using React
◦ server application built using Node.js.
All data such as: accounts and contact lists is stored in a PostgreSQL database on the server and accessed through a REST APIs.
All of the video and audio data is sent from peer to peer without any of it reaching the server. The server is only used to establish the WebSocket connections between peers. For communication, the Socket.io library is used.
Github repository: https://github.com/leoionescu/licenta
2023
Java MongoDB Maven
Implemented a Public Blockchain System
◦ Established the fundamental structure of blocks, including unique block hashes, referencing previous block hashes, timestamps, transactions with sender and recipient addresses, nonces, and Merkle roots.
◦ Used cryptographic hashing algorithms, particularly SHA-256, to calculate block and transaction hashes. These algorithms served as the foundation for security, verification, and consensus within the network.
◦ Included a proof-of-work mechanism to secure the network, control block creation rates, and achieve consensus. We defined target difficulties, crafted block headers, and employed the SHA-256 hash function to validate mined blocks, enhancing the decentralization and security of the blockchain.
◦ Detailed the steps involved in executing transactions within the blockchain, including creation, verification, propagation, inclusion in blocks, and validation.
◦ Designed a local network for nodes to interact, exchange transactions, blocks, and synchronize their blockchain versions.
◦ Developed a synchronization mechanism to ensure new nodes join the network with the latest valid blockchain version.
Github repository: https://github.com/leoionescu/Public-Blockchain
2020 - 2021
Android Java Firebase
Music Streaming App for Android (Spotify Clone)
◦ Leveraging the Deezer API, the app pulls real-time chart data, providing users with a wide range of music options.
◦ The integration of YouTube functionality allows seamless song playback with or without video.
◦ The app's playlist creation, recommendation, shuffle, repeat, and queue management features ensure a tailored music experience.
Github repository: https://github.com/leoionescu/Spotify-Clone-Android
Live Demo available at: https://appetize.io/app/w5iuqq7xxu56x5am2iijgnrjxq?device=pixel4&osVersion=11.0&scale=75
2023
React Tailwind CSS
Portfolio
This is the page that you are currently browsing.
Github repository: https://github.com/leoionescu/portfolio
2018
Java Greenfoot
Taka's Adventure
This is a 2D platformer game, built in Java using Greenfoot, where you will help Taka collect all the diamonds and get home, while surviving the angry skeletons that attack him every time he gets near them.
Github repository: https://github.com/leoionescu/Taka-s-Adventure
Live Demo available at: https://www.greenfoot.org/scenarios/29255
2021
JavaScript HTML CSS
JavaScriptMusicPlayer
This app is built using vanilla javascript, html and css and its main goal is to play different songs. You can play, skip, shuffle, change the volume or go to the previous song. If ran in Google Chrome, the app shows a sinewave graph of the audio currently playing.
Github repository: https://github.com/leoionescu/JavaScriptMusicPlayer
Live Demo available at: https://festive-kowalevski-d3642a.netlify.app/
2021
JavaScript HTML CSS
ChartsForEuropeanCountries
This app shows bar charts and bubble charts for GDP, Life Expectancy and Population in European Countries between 2005 and 2019 and the evolution of these indicators through an animated bubble chart.
Github repository: https://github.com/leoionescu/ChartsForEuropeanCountries
Live Demo available at: https://goofy-jang-dae835.netlify.app
The app fetches data from: https://ec.europa.eu/eurostat