Hello, I'm
Kristian Lonergan
Senior Frontend Developer
Crafting exceptional user experiences with modern web technologies and a passion for clean, efficient code 🚀
About Me
As a Senior Frontend Developer with extensive experience in building modern web applications, I specialize in creating responsive, performant, and accessible user interfaces using React, TypeScript, and modern CSS frameworks.
My expertise includes:
- Modern React development with TypeScript 📚
- State management with Redux, Context API, and React Query 🧠
- Building responsive layouts with Material UI and Tailwind CSS 🎨
- Performance optimization and web vitals 🚀
- Component-driven development with Storybook 📚
- Testing with Vitest and Playwright 🧪
Technical Skills
Frontend
React
TypeScript
JavaScript
HTML5/CSS3
Material UI
State Management
Redux
Context API
React Query
Testing
Jest
React Testing Library
Cypress
Playwright
Vitest
Tools & Others
Git
Next.js
Vite
Storybook
Figma
Work Experience
Proplyon
January 2024 - Present
Senior Frontend Developer
January 2024 - Present
- Leading frontend development initiatives using React, TypeScript, and Material UI
- Successfully migrated and optimized Cypress E2E test suite to Playwright, significantly improving test reliability and speed
- Architecting and developing specialized Microsoft Word add-ins using Office.js and React
- Leading bi-weekly code reviews and providing technical mentorship to junior developers
- Implementing critical performance optimizations for improved application responsiveness
- Establishing frontend best practices and documentation standards for the team
- Collaborating with UX designers to implement accessible and responsive interfaces
- Contributing to technical architecture decisions and technology selection
Rezexe
March 2020 - December 2023
Senior Frontend Developer
January 2022 - December 2023
- Spearheaded frontend development using React, TypeScript, and Material UI for a high-traffic marketplace platform
- Architected and developed a Next.js application for AWS container health monitoring with real-time updates
- Implemented comprehensive CI/CD pipelines to streamline deployment processes
- Led a team of frontend developers, conducting regular code reviews and technical mentoring sessions
- Established and documented frontend best practices, significantly improving code consistency
- Designed and implemented comprehensive E2E testing strategy using Cypress
- Optimized application performance and core web vitals metrics
- Collaborated with product managers to refine feature requirements and technical specifications
Frontend Developer
March 2020 - December 2021
- Developed key features for a marketplace platform using React and TypeScript
- Implemented responsive layouts and components using Material UI and custom styling solutions
- Built and maintained a reusable component library to accelerate feature development
- Integrated REST APIs and implemented state management using Redux and React Query
- Collaborated with backend team to design and optimize API endpoints
- Participated in agile ceremonies and contributed to sprint planning and estimation
- Implemented comprehensive unit tests using Jest and React Testing Library
✈️
Personal Development
September 2019 - February 2020
Career Break - European Travel
September 2019 - February 2020
- Took a strategic career break to broaden international perspective and cultural understanding
- Explored tech hubs in Barcelona, Lisbon, and other European cities
- Attended tech meetups and conferences to stay current with industry trends
- Completed online courses in modern web development technologies
IBM
June 2014 - August 2019
Software Engineer
April 2017 - August 2019
- Developed and maintained enterprise web applications using Dojo and JavaScript
- Led migration initiatives from legacy systems to modern JavaScript frameworks
- Implemented Java backend services and RESTful APIs
- Contributed to architecture decisions and technical documentation
- Mentored junior developers and conducted technical training sessions
- Collaborated with global teams across different time zones
- Developed proof of concept applications using React and modern web technologies
Software Test Engineer
June 2015 - March 2017
- Designed and implemented automated test frameworks using Java and Selenium
- Significantly reduced manual testing effort through comprehensive test automation
- Created and maintained test plans and test cases for critical applications
- Collaborated with developers to implement testing best practices
- Conducted performance testing and identified system bottlenecks
- Maintained continuous integration test suites
Software Test Engineer Intern
June 2014 - May 2015
- Learned and implemented test automation using Java and Selenium
- Assisted in developing and maintaining automated test suites
- Participated in agile development processes and daily standups
- Documented test cases and procedures for future reference
- Collaborated with senior team members on quality assurance initiatives
Get In Touch
Contact Information
I'm always interested in hearing about new projects and opportunities. Feel free to reach out!