Kaan Dura, Developer in Istanbul, Turkey
Kaan is available for hire
Hire Kaan

Kaan Dura

Bio

Kaan is a seasoned full-stack mobile application developer with eight years of experience building high-traffic, responsive apps using Node.js, MongoDB, PostgreSQL, TypeScript, and React Native. He has deep expertise in optimizing mobile applications to handle thousands of daily users without compromising speed or stability, achieving a 99.9% crash-free rate. Kaan has delivered successful apps for multiple startups and holds a computer engineering degree from Boğaziçi University, class of 2021.

Portfolio

Sports Card Investor, LLC
React Native, Mobile Development, Amazon Web Services (AWS), Node.js, MongoDB...
Tavan
React Native, React, APIs, CSS, HTML, Android, iOS...
Tavan
JavaScript, MongoDB, Node.js, APIs, MongoDB Atlas, Google Cloud Platform (GCP)...

Experience

  • React Native - 8 years
  • Node.js - 8 years
  • JavaScript - 8 years
  • Minimum Viable Product (MVP) - 8 years
  • Serverless Framework - 6 years
  • MongoDB - 5 years
  • Express.js - 5 years
  • Python 3 - 3 years

Preferred Environment

Node.js, React Native, Python 3, MongoDB, Amazon Web Services (AWS), CI/CD Pipelines, TypeScript, Expo, PostgreSQL, Sentry

The most amazing...

...achievement was building and migrating a new API for an app with 10,000+ daily users, ensuring zero downtime through phased deliveries.

Work Experience

Full-stack React Native Engineer

2021 - 2025
Sports Card Investor, LLC
  • Migrated a legacy API with over 100 endpoints to a modern serverless architecture with caching, improving scalability, and allowing seamless performance for 10,000+ daily users of the Market Movers app.
  • Delivered major performance upgrades in versions 3 and 4 of the Market Movers app, incorporating Vision Camera for image recognition feature and adopting high-performance list rendering with FlashList.
  • Stabilized two high-traffic mobile apps, reducing crash rates by 30% and ensuring smooth performance as daily active users scaled to 10,000 and 15,000, respectively.
  • Migrated the mobile app from pure React Native to Expo for a significant version change, streamlining development workflows and improving maintainability.
  • Improved the Sports Card Investor app performance by replacing a glitch-prone horizontal swiper with a pager-view swiper, eliminating rendering issues and enhancing user experience.
  • Re-engineered the back end from a JSON-file–based system to a scalable serverless architecture with API caching, enabling the app to handle up to 15,000 daily users for Sports Card Investor version 1.
  • Built and maintained the company's mobile app, Sports Card Investor, and Market Movers. In total, they have more than 25,000 daily users.
Technologies: React Native, Mobile Development, Amazon Web Services (AWS), Node.js, MongoDB, PostgreSQL, iOS, Android, React, CI/CD Pipelines, Mobile App Development, Expo, GraphQL, API Integration, Single Sign-on (SSO)

React Native Developer

2019 - 2020
Tavan
  • Developed a mobile application for the startup. I coded both products of the company using React Native. The route recommendation product required heavy usage of Google Maps.
  • Deployed the mobile to both App Store and Play Store. Managed over-the-air updates using Microsoft App Center.
  • Used Jira for Agile software development, even though I was the only developer working on front-end of the application.
Technologies: React Native, React, APIs, CSS, HTML, Android, iOS, Minimum Viable Product (MVP), Google Maps, Google Maps API, Google Geocoding API, App Development, Agile, Mobile App Development

Back-end Developer

2019 - 2020
Tavan
  • Developed the startup's back-end from scratch. The application's first product was a recommendation engine for runners and cyclers, recommending them clothes and equipment for their activities.
  • Led a small team consisting of another developer and a data scientist.
  • Oversaw the launch and deployment processes from beginning to end.
  • Used and learned about different tools, including serverless back-end and front-end development.
  • Developed a route recommendation algorithm as a second product. For that project, I worked with open-source maps, Google Maps API, and Strava API. Basically, we created a new map with roads marked according to their popularity.
Technologies: JavaScript, MongoDB, Node.js, APIs, MongoDB Atlas, Google Cloud Platform (GCP), Serverless Framework, Express.js, Slack, Slack API, Telegram Bots, Python 3, Python, Amazon Web Services (AWS), Next.js, React, Restify, App Development, Minimum Viable Product (MVP), Single Sign-on (SSO)

Mobile Application Developer

2018 - 2018
DentGroup
  • Developed the company's mobile application during a summer internship.
  • Used deployment tools such as App Center for the first time.
  • Oversaw the launch process of the mobile application, including alpha and beta testing, Play Store, and App Store operations.
Technologies: React Native, JavaScript, TypeScript, APIs, Mobile App Development

Experience

Sports Card Investor

https://apps.apple.com/us/app/sports-card-investor/id1533690124
Before I joined the team, the app was built with React Native but faced significant back-end and data pipeline issues. I re-engineered the back end to handle higher traffic, moving away from the initial JSON-file–based data loading to a scalable serverless architecture with API caching. This transition enabled the app to reliably support approximately 15,000 daily users. Over the years, I also delivered multiple UI/UX enhancements. On the React Native side, I improved performance by replacing the glitch-prone horizontal swiper with a smoother pager-view implementation, eliminating rendering issues. For version 2, I contributed to migrating the app to Expo, ensuring better development workflows and maintainability. Additionally, I implemented a React Native and Expo CI/CD pipeline to streamline releases and improve delivery speed.

Market Movers | Mobile App

https://apps.apple.com/us/app/market-movers/id1561027917
A React Native-based mobile app with subscription support and features such as notification events, email links, and universal deep linking. Given its subscription model, performance was a top priority. I delivered major performance improvements across versions 3 and 4 of the app. On the React Native side, I integrated Vision Camera for image recognition and adopted modern list libraries like FlashList. To further optimize speed and scalability, I migrated the legacy API—spanning more than 100 endpoints—to a new serverless architecture with caching capabilities. These changes enabled the app to handle over 10,000 daily users seamlessly. Using Sentry, I reduced the application crash rate by 30%, significantly improving user experience. Additionally, I implemented CI/CD pipelines to streamline releases and accelerate delivery.

Education

2015 - 2021

Bachelor's Degree in Computer Engineering

Bogazici University - Istanbul, Turkey

Certifications

NOVEMBER 2023 - NOVEMBER 2026

AWS Certified Solutions Architect – Associate

Amazon Web Services

Skills

Libraries/APIs

Telegram Bot API, Node.js, Instagram API, React, Google Maps, Google Maps API, Google Geocoding API, REST APIs, Slack API, Restify

Tools

MongoDB Atlas, Expo, Slack, Jira, Sentry

Languages

Python 3, Python, JavaScript, TypeScript, CSS, HTML, SQL, C, C++, GraphQL

Frameworks

React Native, Express.js, Serverless Framework, Next.js, Selenium

Paradigms

App Development, Agile, DevOps, Mobile Development

Platforms

Amazon Web Services (AWS), Google Cloud Platform (GCP), Firebase, Docker, Android, iOS, RevenueCat

Storage

MongoDB, NoSQL, Databases, MySQL, PostgreSQL

Other

Telegram Bots, Software Development, Minimum Viable Product (MVP), Mobile App Development, API Integration, Software Deployment, APIs, Data Scraping, CI/CD Pipelines, Web Scraping, Single Sign-on (SSO), Subscriptions, Push Notifications, Performance Improvement

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring