Krisztian Szalai

Full Stack Developer & React Native Engineer

Over 6 years of experience building web and mobile applications. Specialized in React Native mobile development with a strong foundation in full-stack development.

Krisztián Szalai

Experience

Here's a brief rundown of my work history, key responsibilities, and notable achievements at each company.

StellarUp logo

Senior Frontend Developer

StellarUpBudapest, Hungary

Social Media, Marketing

2023 Sept - Present

Contract

  • Leading the development of Fiona's mobile application using React Native, implementing key features and ensuring high-quality user experience
  • Contributing to the web platform development using Next.js, creating seamless integration between mobile and web interfaces
  • Building a social platform that facilitates connections between influencers and brands for marketing collaborations
  • Implementing best practices and architectural decisions for both mobile and web applications
React NativeNext.jsTypeScriptReactNode.js
Cablesight Inc. logo

Senior Software Engineer

Cablesight Inc.Remote

IT/Networking

May 2024 - July 2024

Contract

  • Developed internal tools and applications on a project basis
  • Migrated a legacy PHP website to a React Native application
  • Created an admin application for user management
  • Developed a project and ticketing management system for both mobile and web platforms
TypeScriptReact NativeReact-native-webNode.jsExpress.jsMySQLPostgreSQL
Gridlock Inc. logo

Full Stack Mobile Developer

Gridlock Inc.Remote

Crypto wallet

January 2023 - February 2024

Contract

  • Led planning and development of data backup feature using Google Drive, iCloud, Keychain, and encryption techniques
  • Implemented in-app purchases and subscriptions for Play Store and App Store
  • Designed and developed offline capabilities for the application
  • Optimized site performance, improved animations, and enhanced UI responsiveness
  • Maintained high coding standards and conducted code reviews
  • Managed deployment processes for both Play Store and App Store
TypeScriptReact NativeNode.jsExpress.jsMongoDBSentryAdaptyRailway
Viddl logo

Full Stack Software Developer

ViddlBudapest, Hungary

Package delivery, E-learning

May 2021 - January 2023

Full-time/Contract

  • Maintained and enhanced web and mobile applications
  • Contributed to complete mobile frontend codebase rewrite for improved scalability
  • Developed multiple E-learning platforms, including HSUP, used by thousands of students
  • Created package delivery tracking application with map view using OpenLayers and VROOM
  • Refactored data structure to improve package status visualization
TypeScriptReactReact NativeExpoNode.jsExpress.jsNest.jsMongoDBHerokuStrapiNx Monorepo
Asseco Central Europe Zrt. logo

Full Stack Web Developer

Asseco Central Europe Zrt.Budapest, Hungary

Healthcare

September 2018 - May 2021

Full-time

  • Contributed to the development of an Information Sharing Platform for Hungarian healthcare organizations
  • Developed a conference platform with audio-video calls using WebRTC technology
TypeScriptAngularExpress.jsXMLHTMLCSSSASS

Services

Specialized development services tailored to your needs, focusing on modern web and mobile solutions.

🌐

Web Development

Building modern, responsive web applications with cutting-edge technologies.

  • Custom web application development
  • Progressive Web Apps (PWA)
  • Frontend and backend integration
  • Performance optimization
  • SEO-friendly development
📱

Mobile Development

Creating cross-platform mobile applications for iOS and Android.

  • React Native development
  • Cross-platform solutions
  • Store deployment
  • Development take over and maintenance
💡

Technical Consulting

Providing expert guidance on technology solutions and architecture decisions.

  • Architecture planning
  • Technology stack selection
  • Code review and optimization
  • Performance auditing
  • Technical documentation

Let's Create Something Amazing

Have an idea? Whether you're a startup with a vision or an established company looking to innovate, I'm here to help turn your ideas into reality. Here's how we can work together:

💡01

Understanding Your Vision

Let's start by exploring your ideas and goals together. I'll help you shape and refine your vision into a concrete plan.

What We'll Do

  • In-depth consultation
  • Goal exploration
  • Technical possibilities
  • Strategic planning

What You'll Get

  • Detailed project vision
  • Technical roadmap
  • Timeline & milestones
  • Resource outline
✏️02

Crafting the Blueprint

Together, we'll design a solution that's not just functional, but scalable and future-proof for your growing needs.

What We'll Do

  • Collaborative design sessions
  • Technology selection
  • User experience planning
  • Security & scaling strategy

What You'll Get

  • System blueprint
  • Technology stack
  • Interactive prototypes
  • Security framework
03

Bringing Ideas to Life

Watch your vision become reality through iterative development. Regular updates keep you involved every step of the way.

What We'll Do

  • Iterative development
  • Continuous collaboration
  • Quality assurance
  • Progress reviews

What You'll Get

  • Working software
  • Quality reports
  • Documented code
  • Progress insights
🚀04

Launch & Growth

Your success is my priority. I'll ensure a smooth launch and provide ongoing support to help your solution thrive.

What We'll Do

  • Strategic deployment
  • Performance optimization
  • Knowledge transfer
  • Growth support

What You'll Get

  • Production release
  • Training resources
  • Maintenance plan
  • Growth roadmap

Ready to Start Your Project?

Whether you have a specific project in mind or just want to explore possibilities, I'm here to help. Let's discuss your ideas and find the best way to bring them to life.

Let's Talk About Your Project

Projects

A selection of my recent development projects and technical achievements.

Fiona

Sep 2024 - Present

MobileWebFrontend

A social platform connecting influencers with brands for marketing collaborations, featuring both a React Native mobile app and a Next.js web application.

React NativeNext.jsTypeScriptNode.jsExpress.jsMongoDB

Router Management System (Cablesight)

Jun 2024 - Aug 2024

WebMobileFrontendBackend

Rewrote an existing PHP-based system into a cross-platform React Native application (including web via react-native-web) for managing routers, networks, and customers.

React NativeReact Native WebNode.jsExpress.jsTypeScriptPostgreSQLDocker

Mobile Crypto Wallet (Gridlock)

Jan 2023 - Feb 2024

MobileBackendFrontend

Led the development of secure data backup, offline mode, and account recovery features for a self-custodial crypto wallet application.

TypeScriptReact NativeNode.jsExpress.jsRust (native module)MongoDB

E-Learning Platform (HSUP)

May 2021 - Jan 2023

WebMobileFrontendBackend

Created a high-availability E-learning platform supporting thousands of students, featuring interactive content, online tests, and collaborative tools.

TypeScriptReactReact Native (Expo)Nest.jsNode.jsStrapiMongoDB

Package Delivery and Tracking System (Viddl)

May 2021 - Jan 2023

MobileWebFrontendBackend

A comprehensive package delivery tracking application with real-time map visualization, route optimization, and courier management.

TypeScriptReactReact NativeExpoNode.jsExpress.jsMongoDBNx monorepo

Online Oncological Healthcare Platform (Asseco)

Jun 2019 - May 2021

WebFrontendBackend

A specialized healthcare platform enabling doctors to share patient data, request second opinions, and conduct video conferences for oncological treatments.

JavaScript (custom framework)AngularNode.jsWebRTCTypeScriptMongoDB

Skills & Technologies

frontend

ReactReact NativeNext.jsAngularTypeScriptJavaScriptHTML5CSS3

backend

Node.jsNest.jsExpress.jsRESTful APIsMongoDBMySQLPostgreSQL

tools

GitGitHubJestReact Testing LibraryExpoRailwayHeroku

other

WebRTCCI/CDAgileNx MonorepoStrapiApp StorePlay Store

Get in Touch

Contact Information

Email: krisztwos@gmail.com

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