Stefan is available for hire
Hire StefanStefan Radacovsky
Verified Expert in Engineering
Spring Cloud Developer
Prague, Czech Republic
Toptal member since October 1, 2020
Bio
Stefan has been working for financial companies throughout his entire career. In the beginning, he started as a back-end programmer, then he took some technical team lead roles and later added skills in analysis and design. Over the past few years, he has found and enjoyed more opportunities on the front end.
Portfolio
Raiffeisenbank
PostgreSQL, Spring Boot, Swagger, JSON, REST APIs, NgRx, RxJS, Webpack...
UV Partners, Inc.
Angular, JavaScript, CSS, HTML, Data Visualization, Pixel Perfect, AWS IoT Core...
Československá obchodní banka, a.s.
Sparx Enterprise Architecture, Spring Boot, SOAP, Java
Experience
Availability
Full-time
Preferred Environment
Azure, Liferay, SQL, Spring Cloud, Docker, REST APIs, Spring Boot, TypeScript, Angular, Java
The most amazing...
...thing I have created is a dashboard page for a Czech bank's internet banking app. I did requirements collection, analysis, technical design, and implementation.
Work Experience
Front-end Architect
2018 - PRESENT
Raiffeisenbank
- Designed and implemented a new retail front end used for new client onboarding by all 119 branches of the bank.
- Implemented the proof of concept of Czech ID optical recognition and data mining.
- Oversaw the quality of work of four junior developers on the project.
- Presented the first version of the application to the CEO and the bank board. I demonstrated the process of new client onboarding in less than eight minutes. It took more than 40 minutes the old way.
- Presented the application to pilot users and collected their feedback.
- Served as a temporary back-end developer after the main back-end developer resigned. I served as a back-end developer for six months and maintained quality, know-how, and continuity until the bank could hire a replacement.
Technologies: PostgreSQL, Spring Boot, Swagger, JSON, REST APIs, NgRx, RxJS, Webpack, TypeScript, Angular
Angular Developer
2020 - 2023
UV Partners, Inc.
- Maintained and improved an Angular-based dashboard web application.
- Implemented charting and indoor mapping using Chart.js and Mapbox libraries.
- Implemented various POC applications using React for investor presentations.
- Designed and implemented a user signup process with Amazon Cognito.
- Implemented GraphQL handlers, MongoDB aggregations, and queuing logic in AWS environment.
- Cooperated closely with CTO, helping him improve on his ideas and realizing them.
Technologies: Angular, JavaScript, CSS, HTML, Data Visualization, Pixel Perfect, AWS IoT Core, Amazon Cognito, React, Mapbox SDK, Chart.js, Serverless, MongoDB, GraphQL, Cypress, TypeScript
Senior Back-end Developer
2017 - 2018
Československá obchodní banka, a.s.
- Set up the implementation of a new retail banking back-end from grounds up. I chose the technology, prepared a development environment, and delivered the proof of concept. The back end serves eShop and branch office applications.
- Set up a continuous development environment using Bitbucket, Jira, and Bamboo.
- Communicated with analysts, maintained the backlog, and coordinated work with team members.
- Interviewed the developer candidates for the new project.
- Tutored all new hires, bringing them up to speed and quality.
Technologies: Sparx Enterprise Architecture, Spring Boot, SOAP, Java
Senior Full-stack Developer
2017 - 2018
Tieto Corporation
- Designed and implemented REST microservices for managing code lists used by all other microservices of a new pension insurance calculation system.
- Designed and implemented the proof of concept of a secure cloud-ready microservice platform based on Spring Cloud. It implemented a concept of micro front ends. It was used to recruit a new customer successfully.
- Implemented the authentication of Finnish citizens using KeyCloak and KaPa, Finnish National Services.
- Implemented a front-end application for managing code list values used across all subsystems.
- Stepped in during and implemented business processes in the JBPM Suite after the sudden resignation of a team member. Delivered the required business processes for one month until a new colleague took over.
Technologies: Swagger, jBPM, Docker, OpenShift, Webpack, JSON, REST APIs, Spring Boot, Keycloak, GoCD, Angular, Java
Senior Front-end Developer | Analyst
2016 - 2017
Československá obchodní banka, a.s.
- Implemented a dashboard portal in a retail banking web application that is the first page all 4.2 million retail clients see after their login.
- Implemented Liferay portals using the Vaadin framework and communicating with back-end SOAP web services.
- Oversaw the business requirements collection from various competing bank departments and navigated the company politics ensuring timely delivery.
- Transformed raw business requirements into technical analysis that conformed to the clients' internal rules.
- Created the technical design for a portal that showed the bank client's overall financial position. This portal was accessing data from multiple back ends at the same time and was used by 4.2 million customers.
Technologies: Sparx Enterprise Architecture, Liferay, Spring, Vaadin, Java
Senior Back-end Developer | Technical Team Leader
2015 - 2016
Barclays Capital Services
- Led a team of seven people split between manual testers and test automation developers.
- Developed an in-house harness for test automation using fluent interfaces and business-friendly reporting.
- Developed and maintained a stock exchange simulator that provided mocking responses using the FIX protocol.
- Created a harness for automated regression testing of a high-frequency order management system (OMS).
- Interviewed and tutored new team members, ensuring quality and continuity of deliveries.
- Managed project backlog and prioritization and served as a partial Scrum Master.
Technologies: FIX Protocol, Ranorex, Vaadin, Spring, Apache Camel, Java
Senior Software Developer
2014 - 2015
Commerzbank AG
- Took over a project without proper documentation and reverse-engineered the technical documentation.
- Maintained and developed new features of a system responsible for the bank's regulatory reporting.
- Maintained and developed new features of a system for the management of syndicated loans.
Technologies: IBM Db2, SQL, Spring, Java
Technical Team Lead
2007 - 2014
Deutsche Boerse Systems Services
- Helped set up a new near-shoring development center in Prague, Czech Republic. I became the head of the unit responsible for developing a securities clearing system.
- Oversaw the building of a team of eight people. I hired new talents, mentored them, evaluated their performance, and motivated them.
- Completed the technical analysis and implementation of changes into the securities clearing system, allowing the stock exchange to automate the clearing of securities lending trades.
- Provided L3 on-call support for the clearing system, helping solve middle-of-the-night problems, and allowing the stock exchange to start up on time in the morning.
Technologies: JDBC, Ant Design, JavaScript, PL/SQL, Oracle Rdb, JBoss, WebSphere, VMS, Data Control Language (DCL), Java, C
Junior Developer
2005 - 2006
Vigour
- Developed new screens for the client management system of the Czech social security ministry.
- Built an eCommerce based on the IBM eCommerce product for a company's client.
- Created new functionality in the loan management system of a Czech retail bank.
- Developed an XSLT transformation of customer data in a time-critical project for a Czech insurance company.
Technologies: Visual Basic, UML, Bash, PL/SQL, XSLT, XML, Jakarta Server Pages (JSP), Jakarta EE, Java
Experience
Internet Banking Dashboard
When 4.2 million clients of a Czech bank log into their internet banking application, they are greeted by a dashboard that shows all their financial positions. I have met with all the business people from various bank departments, collected their requirements, wrote analysis and technical designs, and implemented the dashboard itself.
Stock Exchange Simulator
A FIX protocol simulator of various stock exchanges. When I worked as a test harness developer and technical team lead for a British bank, my team was tasked with implementing automated regression tests for its order management system. The system connected to various stock exchanges and communicated client's orders to them. The problem was that it was unreliable and expensive to connect to real exchange test endpoints. It caused a lot of false positives. I developed an exchange simulator that allowed us to programmatically set up mocks of various stock exchanges and simulate their behavior in relation to order intake.
Toptal React Academy
The Toptal React Academy is an exclusive learning program that teaches the React framework to select members of the Toptal network. After a month of study, all graduates are tasked with completing a 30-40 hour final project to build and deliver a React app from scratch. The above is a walkthrough of my final project.
Education
2008 - 2010
Master's Degree in Economics and Management of Power Engineering
Czech Technical University of Prague - Prague, Czech Republic
2004 - 2007
Bachelor's Degree in Computer Science
Czech Technical University of Prague - Prague, Czech Republic
Certifications
DECEMBER 2020 - PRESENT
Toptal React Academy Graduate
Toptal, LLC
APRIL 2020 - PRESENT
Microsoft Certified: Azure Fundamentals
Microsoft
DECEMBER 2015 - PRESENT
Oracle Certified Associate, Java SE 7 programmer
Oracle
DECEMBER 2013 - PRESENT
How to Gather and Document User Requirements
ESI International
Skills
Libraries/APIs
REST APIs, RxJS, NgRx, JDBC, JAXB, React, Chart.js
Tools
Webpack, Keycloak, Amazon Cognito
Languages
Java, TypeScript, SQL, JavaScript, C, Data Control Language (DCL), XML, XSLT, Bash, UML, Visual Basic, CSS, HTML, GraphQL
Frameworks
Angular, Spring Boot, Swagger, Spring, Vaadin, jBPM, Apache Camel, Ranorex, Ant Design, Jakarta Server Pages (JSP), Cypress
Paradigms
Requirements Analysis
Platforms
Jakarta EE, Docker, Azure, OpenShift, WebSphere, JBoss, AWS IoT Core
Industry Expertise
Accounting, Project Management
Storage
JSON, PostgreSQL, IBM Db2, Oracle Rdb, PL/SQL, MongoDB
Other
Spring Cloud, Liferay, Software Development, Software Development Management, Economics, GoCD, SOAP, Sparx Enterprise Architecture, FIX Protocol, VMS, Data Visualization, Pixel Perfect, Mapbox SDK, Serverless
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