About Me
A bit about me,my work experience, interests, and the journey that got me here. Exploring new tech, building cool things, and always learning.
Rouselakis Stylianos
Hello! You can call me Stelios. I'm a software engineer with a strong focus on React, Next.js, and backend optimizations. Over the past years, I’ve been actively developing high-performance applications, working with technologies like React Query, TypeScript, Node.js, and Keycloak for secure authentication.
My journey started in web design and freelancing, where I built websites and custom applications for clients. This hands-on experience led me to dive deeper into frontend and backend engineering, optimizing databases with MySQL, caching with Redis and Memcached, and ensuring smooth deployments with Kubernetes and CI/CD pipelines.
Outside of coding, I’m passionate about home automation, always looking for new ways to make my setup smarter. I also enjoy playing board games with friends and challenging myself with puzzle mobile games. Whether it's automating my home or solving a tricky puzzle, I love exploring new ways to think and improve.
Feel free to explore my projects and see what I'm working on next!
Work Experience
Software Engineering Team Lead
Upstream
Athens
2017 — Present
- •Developed and maintained an Agile team culture by facilitating team building activities and promoting an environment of continuous improvement. Following Agile practices, JIRA is our primary task management tool. Conducting daily stand-ups, sprint planning, retrospectives, and frequent reviews. I make sure there is a clear direction while also allowing room for creativity and autonomy.
- •Improved team morale and motivation through positive reinforcement and team building activities, resulting in improved team performance. Constantly helping developers grow by guiding them in technical decisions and supporting their professional development. Strong believer of knowledge sharing, encouraging Code reviews and the exchange of technical expertise.
- •Identified and addressed impediments to team progress and success, resulting in a smoother flow of work and improved team morale. I oversee code reviews, making sure the code is clean, efficient, and maintainable. We continuously optimize our pipelines, integrating testing and monitoring with Prometheus metrics.
- •Communication with other teams & stakeholders: My role requires frequent interaction with product managers, business stakeholders, and other teams within the company to align technical solutions with business goals.
- •Very proficient at Laravel PHP Framework along with VueJS to accompany the back-end system. Developed a full blown CMS with the above technologies, that manages all the aspects of creating and launching Web Campaigns.
- •Moving our technology stack from VueJS to React, I have been actively developing our latest application for the past years with React. React technologies we are currently involved in active development are: Next JS, React Queries, Node JS Backend To Support Next JS Frontend (Server Side Rendering), Typescript, React Unit Testing using Jest, Redux Toolkit, Styled-Components, Authorization using an external open-source server Keycloak, Developing Custom NPM Packages using Verdaccio (Private NPM Repository).
- •Due to very high Internet Traffic Requirement of the campaigns, acquired expertise with MYSQL optimization, utilizing Redis Key-Value Storage and Memcached as another caching layer. Experience with Varnish cache server as well, since it was used as a content delivery network for all assets, including js, img, font files.
- •Our logging system was very extended, as a result I became familiar with Apache Hadoop, Kafka Brokers, Avro Messages, as well as querying large Data from HDFS File Systems.
- •Familiar with CI /CD procedures, since we are actively monitoring our Kubernetes Infrastructure. The tools we are using involve Kubectl Command Line, Prometheus for measuring our Web application Metrics and displaying them at Grafana.
Web Designer – Freelancing
Self – Employed
2015 — 2018
- •Worked in developing mainly Websites for the needs of each client. Furthermore, as a side hassle, developed several Java / JavaScript applications for customers, that wanted some specific application to help them in their field.
- •Worked and became familiar with Joomla, WordPress and Drupal Content Management System platforms.
- •Used countless plugins for both systems and became more familiar with PHP code. Most sites require the use of plugins to minimize CSS/HTML in order for the pages to load faster to the front-end user.
- •Learned what needs to be done, so that the website ranks good in Page Speed Tests. Developed SEO skills, so that the pages rank good on Search Engines, focusing on the right keywords.
- •Set up my personal website, on a Virtual Machine Windows Server 2008 and hosted it there using IIS Windows Server Services.
Network Systems Engineer
Hellenic Army Athens (N.M.T.S. Hospital)
Athens
2015 — 2016
- •Worked in the IT Department as a Computer Programmer - Analyst.
- •Provided users with help desk support regarding software, hardware and active directory issues; Microsoft Office, program installation, operating systems errors, user details update.
- •Performed installation, support and repair of the IT systems.
- •Coordinated the training of new personnel in all the above tasks.
Call Center Representative
Hellenic Telecommunications Organization
Patras
2011 — 2014
- •Worked in the 13888 Department as a Representative, establishing new connections to the internet for customers and supporting any issues related to Internet Connectivity.
- •Supported tasks related to logistics, HR and internal communication of the organization, customer support and product promotion.
- •Developed excellent organizational, leadership and communication skills as well as ability to perform highly demanding tasks under time and resources pressure.
Network Coordinator
Political Party
Athens
2008
- •There was an election for the president of a political party. A Virtual Private Network was used in order to accredit the voters.
- •Coordinated the three centers so that the process of voting for the election is done correctly with ease and methodicalness.
- •Custom Software was used in order to accredit the voters and prevent double voting. User training was required in order to be used properly. Executed the training of all the computer users that took part in the voting process in the province of Achaia.
Education
Electrical & Computer Engineering
2006 — 2012
University of Patras, Patras
- •Field of Expertise : Computer Engineering & Programming
- •Thesis Title « Design a Program for solving Chess Problem Situation & Utilizing Smart Algorithms». Developed using C Programming Language.
Hobbies & Interests
TravelingI love to travel and explore new places, meet new people, and learn about different cultures.
Board GamesPlaying board games with friends and family.
Home AutomationI enjoy building and automating smart home systems.
ChessPlaying chess and improving my skills.
BikingI enjoy biking and traveling through the city.
GymWorking out and staying fit.