Kostiantyn D.

After wrapping up my last contract, I took a sabbatical to build a personal project and explore the new development tools and approaches - while taking on freelance consulting and short-term engagements focused on TypeScript and Vue, staying sharp in the framework I love most and keeping one foot in real client work

• Designed and built a generative content and insight web application: backend, frontend, ui, database, build pipeline, and deployment
• Chose a lean, server-rendered architecture on Bun and Hono with type-safe JSX templating processed by Kita Html, deliberately favoring performance and minimal client-side JavaScript over heavier all-in-one frameworks; layered in Swup for smooth, app-like page transitions
• Created lightweight Bun plugins for live-reload, fine-grained asset bundling, and project-focused transformations rather than reaching for a full build tool like Vite - a deliberate choice for a fast development loop and a lean build
• Built a fully type-safe TypeScript codebase backed by SQLite and Drizzle ORM, with schema-driven migrations and Valibot runtime validation
• Made type-safe file-based LLM-powered content generation a core part of the product, and used those workflows to power internationalization (i18n) - so new languages and localized content can be added and adapted with minimal manual effort
• Delivered the app as an installable Progressive Web App (PWA), ready to tranform into dedicated mobile apps

I've really enjoyed this time. With the app now built and live, my full focus is on what's next: a long-term role on a strong team where I can contribute deeply and make a lasting impact.

• Developed architecture for frontend applications within a large-scale Big Data API ecosystem, ensuring scalability and performance
• Developed and maintained a project-specific component library and design system
• Built high-performance frontend applications using Vue.js, Svelte, and TypeScript, improving efficiency and maintainability
• Actively contributed to backend development using Node.js
• Established code review practices to maintain consistency and code quality across the team
• Continuously stayed up to date with frontend technologies, adopting new tools and practices to improve team efficiency and product quality

• Transformed a verbally described idea into a concrete MVP scope through iterative discovery and requirements refinement
• Built wireframes, user flows, and relationship diagrams to validate logic early and make scope testable
• Prototyped the UI with dummy data (Gulp, Pug, SCSS/BEM, TypeScript) to finalize visuals and page structure before backend development
• Implemented the backend in Laravel 10, including models, migrations, routing, caching, validation, and authentication flows (Sanctum); integrated the frontend using Blade templates and connected it to live data; documented the API using Swagger
• Delivered a custom dashboard for dynamic content creation (Inertia.js + Vue 3, Arco Design, Tiptap with project-specific WYSIWYG extensions), including image processing (optimization and post-filter presets) and an OpenAI-assisted editing workflow inside the editor
• Integrated SERP/snippet previews into the dashboard, implemented JSON-LD schema generation, built a dynamic OG image generation service per content item, and added lazy loading; achieved PageSpeed Insights scores of 100/100 (mobile and desktop)
• Set up production infrastructure on an Ubuntu VPS with NGINX, implemented CI deployments via GitLab (dev and production), and created documentation and a style guide; also supported the transition as a technical and architecture consultant during handover

• Contributed to the development and maintenance of a micro-frontend orchestration shell within a well-architected infrastructure, delivering features across multiple environments using Vue.js, Svelte, and TypeScript
• Played a key role in implementing new micro-frontend applications, contributing to a central component library and routing system that enabled faster development and consistent user experiences
• Enhanced and refactored components within the central library, ensuring consistency and long-term maintainability through clean abstractions
• Implemented and maintained unit and integration tests, improving application stability and reducing time spent on bug fixes
• Participated in code reviews, ensuring adherence to best practices and code quality standards
• Actively contributed to backend development using Node.js
• Established code review practices to maintain consistency and code quality across the team
• Continuously stayed up to date with frontend technologies, adopting new tools and practices to improve team efficiency and product quality

• Led the frontend implementation of the user dashboard, payment flows, and PWA support, with a strong focus on reliability and edge-case handling
• Built real-time application features using WebSockets, enabling live statuses, notifications, and app-wide data updates
• Delivered IoT-connected product functionality by integrating APIs from custom ROM router hardware and related equipment, including a live map with real-time device and active user data
• Built scalable multi-role user flows with protected routes, role-specific interfaces, internationalization, and structured Vuex state management
• Collaborated with backend engineers on API contracts to ensure stable, maintainable, and well-aligned integrations as the product evolved
• Established reusable frontend foundations by building a project-specific component library, including complex form abstractions with backend-first validation and streamlined error mapping, improving consistency across the application

• Delivered diverse projects for clients: CMS-based websites, premium CMS templates/addons, frontend enhancements and optimizations, and custom web applications from scratch
• Built full-stack solutions using Vue.js, Laravel, Node.js, AdonisJs, and Express.js
• Developed and maintained component libraries and design systems in Vue.js for efficient UI development across projects
• Achieved measurable improvements in speed optimization, SEO, and quality audits, resulting in better site rankings and reduced load times
• Identified and resolved performance bottlenecks, security vulnerabilities, and code maintainability issues
• Worked with clients to gather requirements, provide estimates, and offer technical guidance
• Managed projects using Jira, Azure, and YouTrack, tracking progress and providing regular client updates

• Developed frontend solutions for Magento and OpenCart e-commerce platforms, delivering user-friendly designs on schedule
• Utilized Git, Docker, and Linux to optimize development workflows and deployment processes
• Implemented responsive designs ensuring consistent user experiences across devices and browsers
• Identified and resolved performance issues, bugs, and usability concerns, improving site stability and conversion rates
• Mentored colleagues in frontend development best practices and techniques
• Contributed to project planning, requirements gathering, and timeline estimation

• Created responsive frontend designs for CMS-based websites from Photoshop and Zeplin mockups
• Developed responsive email templates optimized for various devices and email clients, improving engagement and click-through rates
• Worked with CSS, HTML, JavaScript, PHP, Angular, and Git
• Customized and extended various CMS platforms to meet client requirements
• Implemented web accessibility best practices for inclusive user experiences
• Worked alongside designers, developers, and project managers on project delivery
• Participated in code reviews and knowledge sharing sessions