JavaScript/TypeScript, HTML/CSS, React.js/Next.js and Node.js/Express.js/Nest.js🚀

• Full-Stack Developer with nearly 3 years of production experience, specializing in building and optimizing complex business applications. Proven expertise in architecting scalable systems, delivering high-performance solutions, and leading technology decisions across the full development stack.

• Uniquely positioned with PhD in Ecology (Bacillus thuringiensis research) bringing scientific methodology to software engineering: systematic problem decomposition, data-driven decision making, hypothesis-driven development, and rigorous testing mindset. This rare combination of academic research rigor and production development experience enables me to deliver robust, scalable solutions for complex technical challenges.

• Full Stack Developer: Over 3 years of experience in developing comprehensive web applications:
• Backend Development: Expertise in building RESTful APIs, user authentication and data management using Node.js, Express, Nest.js, PostgreSQL and MongoDB.
• Frontend Development: Proficient in creating responsive and interactive user interfaces with React, Redux, Next and modern JavaScript frameworks.
• Problem Solving: Proven ability to troubleshoot and resolve complex technical issues, ensuring smooth and efficient application performance.
• Database Management: Experienced in designing and maintaining robust databases, ensuring data integrity and security.
• Collaboration: Strong communicator and team player, effectively collaborating with cross-functional teams to achieve project goals.
• Portfolio Projects: Developed and deployed various projects, including CRM systems, movie search applications, recipe management apps, and energy solution landing pages.

• Built over 15 web projects — from CRM systems and high-load applications to responsive landing pages with backend integration, email services, and third-party APIs.

• Designed the application and coded my own narrow-field expertise into its logic, making complex tasks at the level of laboratory head/candidate of science accessible to users without special training.

• Implemented frontend-backend integration in more than 10 projects using modern technologies: Node.js, NestJS, MongoDB, PostgreSQL, RTK Query. Ensured secure data exchange, fast client-server interaction, and real-time synchronization.

• Implemented an authorization system (JWT, Redux, email verification) and role-based access control in more than 8 products, ensuring data protection and privacy.

• Built a full cycle of CRUD operations for data management (users, contacts, products, orders, recipes) — for a total of 12+ solutions and applications.

• Created scalable and adaptive UI interfaces for different types of users, using modern libraries (React, Next.js, TypeScript, Material-UI), implemented themes, drag-and-drop, interactive widgets (weather, date, timers, music player).

• Optimized performance and loading time, implemented SSR, SSG, advanced routing, image processing automation, minimized project size (e.g., from 60GB to 8GB in Shop).

• Developed complex business logic for beauty, e-commerce and military sectors (CRM “Mriya,” Confidential Military System, Booking), migrated legacy projects to a modern stack (React→Next.js+TS), optimized the operation of systems with a large number of concurrent users.

• Implemented email automation, notifications, subscriptions, and PDF generation in many solutions.

• Ensured adaptability and retina optimization in all UI/UX solutions, understanding the importance of mobile experience (especially for beauty and e-commerce).

• I am able to collaborate effectively with multidisciplinary teams: designers, team leads, backend developers, stakeholders, quickly implementing technical solutions in business contexts aimed at results (conversion metrics, usability, retention, and speed of service).

• 🌍 I'm based in Україна

• 🖥️ See my portfolio at My portfolio

• ✉️ You can contact me at kryzhanivskyi.an@gmail.com

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