Daniel is available for hire
Hire DanielDaniel Song
Verified Expert in Engineering
Mobile and Web Developer
Silver Spring, MD, United States
Toptal member since August 8, 2023
Bio
Daniel is an open-minded web and mobile developer who has spent most of his career in mobile and web development. He specializes in React Native, Expo, JavaScript, TypeScript, React, Next.js, GraphQL, Firebase, REST APIs, Node.js, and Agile software development. In the last 14 years, he has developed and published many applications in various industries. Daniel aims to reach maximum efficiency with every project and use both to improve and deliver a high-quality product.
Portfolio
LZF Labs LLC
React Native, React Native for Web, OpenAI, ChatGPT API, Supabase...
Naked Apps LLC
React Native, Node.js, Full-stack, JavaScript, Mobile Development, DigitalOcean...
NowYouKnow Neuro
iOS, React Native, Mobile App Development, WordPress, React, Swift, Objective-C...
Experience
- Mobile Apps - 15 years
- Agile Software Development - 12 years
- React Native - 10 years
- JavaScript - 10 years
- REST - 9 years
- React - 8 years
- TypeScript - 8 years
- GraphQL - 6 years
Availability
Part-time
Preferred Environment
OS X, Slack, Front-end Development, Agile
The most amazing...
...product I've developed is Boatsetter, the number one boat rental platform in the US, available on both web and mobile.
Work Experience
Senior React Native Developer
2025 - PRESENT
LZF Labs LLC
- Developed a mobile/web application (MVP version) named x trivia on iOS and Android using React Native and Supabase (with PostgreSQL).
- Completed the MVP launch from scratch to supporting maintenance, and worked on the React Native (Expo) mobile front end and the Supabase back-end support.
- Implemented LLM grading using OpenAI API and Grok API and designed a good prompt to generate a quiz (for a trivia-style game application).
Technologies: React Native, React Native for Web, OpenAI, ChatGPT API, Supabase, Supabase Auth, TypeScript, PostgreSQL, Large Language Models (LLMs)
Full-stack Mobile Developer
2024 - 2025
Naked Apps LLC
- Developed a mobile social dating application using React Native (front-end), Node.js (back-end), and PostgreSQL (database).
- Tracked and fixed bug and improvement items over the Monday board until the successful V1.0 launch.
- Managed the Testflight release for iOS and the Google Play store internal testing release for Android.
- Handled version control management using Git and the complete agile development process with the team (QA tester, product manager, project manager, and delivery manager).
- Implemented RevenueCat hooks for Apple and Google subscription management (in-app purchase, in-app subscription for membership, managing expiring and cancelling for membership).
- Managed environments on the DigitalOcean cloud for the back-end Node.js server (with full socket connection) and database PostgreSQL for the dev and production environments.
- Contributed to the mobile app. Here's the iTunes (Apple) app store link: https://apps.apple.com/us/app/red-flags-dating-app/id6467825040.
- Contributed to the Android app. Here's the Google Play store link: https://play.google.com/store/apps/details?id=com.redflagsapp.redflags&hl=en.
Technologies: React Native, Node.js, Full-stack, JavaScript, Mobile Development, DigitalOcean, PostgreSQL, TypeScript, Monday.com
React Native Developer
2024 - 2024
NowYouKnow Neuro
- Developed a mobile iOS and Android app for NowYouKnow Neuro.
- Created an app from scratch using React Native version 0.74.
- Viewed a website and followed its code to make the same content.
- Configured navigation by using React Navigation, Used Axios client for web service communication, and used Redux to manage the global state of the app.
- Configured RESTful web service API for PHP plugins on the server side and implemented Q/A view animations.
Technologies: iOS, React Native, Mobile App Development, WordPress, React, Swift, Objective-C, REST, Push Notifications, RESTFul APIs, TestFlight, In-app Purchase (IAP)
Mobile App Developer
2023 - 2024
Running Towards XYZ LLC
- Developed the Wander.ly mobile application using React Native from scratch until the successful product delivery on the Apple and Google Play stores.
- Contributed to an AI-generated animated storybook application for mobile and used React Native for the front end and AWS Amplify Studio for the back end.
- Provided full-stack support (front-end and back-end AWS Amplify Studio, AWS Lambda functions).
- Resolved challenges for using OpenAI story generation scripting with full animation integration into the front end.
- Implemented the subscription feature with Stripe (Apple Pay and Google Pay).
Technologies: React Native, APIs, Mobile Development, React, Amazon Web Services (AWS), Artificial Intelligence (AI), OpenAI, API Integration, User Experience (UX), Chatbots, SQLite, Tailwind CSS, CI/CD Pipelines, Twilio, App Store, Google Play Store, Android App Development, App UI, Push Notifications, Machine Learning, RESTFul APIs, AWS Amplify, TestFlight, ChatGPT API, OpenAI API, In-app Purchase (IAP)
Senior React Native Developer
2023 - 2023
gigElev, Inc. (via Toptal)
- Developed a mobile application using React Native for both iOS and Android platforms, marking my first engagement with Toptal.
- Contributed to the development of an API client utilizing useQuery and played a role in designing the UI/UX for filtering and details pages.
- Handled onboarding walkthrough features, including animation, and implemented Redux stores.
- Participated in the development of an electric car vehicle charge station application.
Technologies: React Native, Python, iOS, Android, REST APIs, Mobile App Development, CSS, HTML, Test-driven Development (TDD), Cross-platform, User Interface (UI), SDKs, Mobile Development, APIs, API Integration, User Experience (UX), Tailwind CSS, CI/CD Pipelines, Expo.io, App Store, Google Play Store, Android App Development, Push Notifications, RESTFul APIs, OAuth, TestFlight, In-app Purchase (IAP), Supabase
Senior Full-stack Engineer
2022 - 2023
Boatsetter Inc
- Built web and mobile applications for Boatsetter, the US's number one boat rental app.
- Handled the front end using Next.js, renter app, and owner app development using React Native.
- Engaged in front-end development and mobile React Native development.
- Experienced in React, Redux, unit testing, and TypeScript.
- Handled the back end using Node.js and Ruby on Rails with Postgre SQL and MongoDB experience.
Technologies: React Native, React, Firebase, Xcode, Android Studio, Azure, Slack, Agile, iOS, Android, App Submission, React Native for Web, GitHub, Next.js, Mobile App Development, Front-end, CSS, Test-driven Development (TDD), Cross-platform, User Interface (UI), Search Engine Optimization (SEO), Expo, SDKs, Mobile Development, APIs, Amazon Web Services (AWS), Front-end Development, API Integration, Web Development, User Experience (UX), Ruby on Rails (RoR), MongoDB, PostgreSQL, Tailwind CSS, GitLab, CI/CD Pipelines, Docker, Full-stack Development, Sentry, Twilio, App Store, Google Play Store, Android App Development, App UI, Push Notifications, Google Cloud Platform (GCP), RESTFul APIs, OAuth, TestFlight, Stripe API, Agile Deployment, In-app Purchase (IAP)
Senior Web and Mobile Developer
2021 - 2022
Revel.xyz (owned by DNA Media Technologies, Inc)
- Developed the social image trading mobile and web application using React Native and React.
- Tracked and fixed bugs using Jira and worked in a team with the Agile development method.
- Oversaw application launch processes. Earned over 10,000 downloads and received great feedback, especially for the UI.
Technologies: React Native, React, Firebase, Agile Software Development, Cloud Firestore, Xcode, GitHub, Agile Project Management, REST APIs, iOS, Android, TypeScript, Jira, App Submission, Mobile App Development, Front-end, CSS, Test-driven Development (TDD), Full-stack, Cross-platform, User Interface (UI), SDKs, Mobile Development, APIs, Web Development, SQLite, GitLab, CI/CD Pipelines, Expo.io, Social Networks, Twilio, App Store, Google Play Store, Android App Development, App UI, Push Notifications, AWS Amplify, OAuth, TestFlight, Streaming, In-app Purchase (IAP)
Senior Mobile Developer
2020 - 2021
ezCater
- Engaged in a 1-year contract to develop a food delivery mobile application now available in the App Store.
- Developed the iOS and Android applications using React Native, TypeScript, and REST APIs.
- Built food delivery and push notification features and performed unit testing and CI/CD.
Technologies: GraphQL, React Native, iOS, Android, Mobile Apps, JavaScript, Objective-C, Java, Cloud, Jest, TypeScript, REST APIs, Unit Testing, Continuous Integration (CI), Continuous Delivery (CD), App Submission, GitHub, Shopify, Mobile App Development, Front-end, Test-driven Development (TDD), Cross-platform, SDKs, Mobile Development, APIs, API Integration, User Experience (UX), Go, Twilio, App Store, Google Play Store, App UI, Push Notifications, Google Cloud Platform (GCP), Firebase, CircleCI, OAuth, TestFlight, Stripe API, Agile Deployment, In-app Purchase (IAP)
Senior Mobile Developer
2019 - 2020
YouSound
- Built an iOS music application to play albums and buy or sell album products.
- Developed the web application using React and JavaScript.
- Launched the application YouSound, which is now available in the App Store.
Technologies: Music, GraphQL, React Native, JavaScript, Stripe, Stripe Connect, iOS, Xcode, React, Web Applications, Mobile Apps, App Submission, GitHub, Shopify, eCommerce, Mobile App Development, Test-driven Development (TDD), User Interface (UI), Expo, SDKs, Mobile Development, APIs, Amazon Web Services (AWS), User Experience (UX), SQLite, Expo.io, App Store, Google Play Store, App UI, Push Notifications, SQL, CircleCI, TestFlight, Stripe API, Streaming, Audio, Agile Deployment, In-app Purchase (IAP)
Principal Software Engineer
2018 - 2019
Building Engines, Inc
- Contributed to the enterprise real estate platform that improves net operating income across the world's most successful commercial real estate portfolios.
- Built a core high-level building module within the employees and accounting module.
- Wrote modularized, scalable, robust, and reusable modules and code to tackle technical debts using best practices.
- Updated accessibility and built different modules for the work order, preventive maintenance, invoice management, equipment, and admin accounting.
Technologies: React, Redux, Jest, Node.js, Cypress, JavaScript, Python, GitHub, Front-end, CSS, HTML, Full-stack, Cross-platform, jQuery, WordPress, SDKs, APIs, Amazon Web Services (AWS), Front-end Development, API Integration, Web Development, Go, Push Notifications, SQL, Firebase, Machine Learning, AWS Amplify, Agile Deployment
Senior Web and Mobile Engineer
2017 - 2017
TheGrint Inc
- Developed the #1 social golf player application in Web and Mobile (iOS and Android).
- Finished Google Map Overlay components tasks and REST API client wrapper tasks.
- Got more than 30k positive feedback from real live users and became the #1 social golf player app in Apple App Store and Google Play Store.
- Contributed to OAuth integration into the application.
Technologies: Agile, React, React Native, REST APIs, Objective-C, Jest, Unit Testing, Agile Software Development, Figma, Front-end, Mobile Apps, iOS, Android, Google Maps SDK, OAuth, App Submission, GitHub, Mobile App Development, CSS, Full-stack, Cross-platform, jQuery, User Interface (UI), Expo, SDKs, Mobile Development, APIs, Front-end Development, API Integration, Web Development, User Experience (UX), Go, Social Networks, App Store, Google Play Store, Android App Development, App UI, Push Notifications, RESTFul APIs, Agile Deployment, In-app Purchase (IAP)
Senior Web and Mobile Developer
2014 - 2016
ClearAppDevelopment, LLC
- Contributed to several projects based on clients' requests.
- Acted as the full-time dedicated lead engineer in a software agency.
- Gained experience in several industries, such as real estate, media, business entertainment, travel, and healthcare.
Technologies: Agile Project Management, Objective-C, Front-end, Next.js, React, Kotlin, Swift, Node.js, MongoDB, iOS, Xcode, Android, Web Applications, Unit Testing, Git, AWS Amplify, GraphQL, REST APIs, JavaScript, CSS, HTML5, jQuery, PostgreSQL, App Submission, Mapbox, Mobile App Development, HTML, Cross-platform, WordPress, Expo, SDKs, Mobile Development, APIs, MySQL, API Integration, Web Development, User Experience (UX), App Store, Google Play Store, Android App Development, Push Notifications, Google Cloud Platform (GCP), SQL, Firebase, Machine Learning, TestFlight
Experience
TheGrint | Golf GPS App
https://thegrint.com/A large-scale social golf GPS application where I worked on the iOS and Android mobile versions using React Native and JavaScript. I also developed a web application using React.
The app includes a Maps SDK that works fully with the GPS tracking feature, drawing overlays on the map view. Finally, I implemented a REST API client to communicate with the back end.
The app includes a Maps SDK that works fully with the GPS tracking feature, drawing overlays on the map view. Finally, I implemented a REST API client to communicate with the back end.
AI Child Story Generator Mobile Application
https://wander.lyWanderly Stories is a cutting-edge React Native app that uses AI to generate personalized children's stories.
PROJECT OVERVIEW
Wanderly Stories aims to revolutionize storytelling for children by providing fresh, AI-generated stories every time. The app's intuitive interface and vibrant illustrations make the reading experience educational and entertaining.
MY INVOLVEMENT
As a key developer, I was instrumental in the app's success. My contributions included:
• React Native development: Ensuring a seamless user experience across the web and iOS.
• AWS Amplify Studio configuration and AWS Lambda function scripting for the back end.
• AI integration: Implementing ChatGPT to generate dynamic stories.
• UI/UX design: Collaborating on an intuitive and appealing interface.
• Testing and debugging: Ensuring smooth and efficient app performance.
• Deployment: Managing the launch and updates for both platforms.
My expertise and dedication brought this innovative project to life, offering children a magical storytelling experience.
iOS app: https://apps.apple.com/us/app/wanderly-stories/id6475022201?platform=iphone
Android app: https://play.google.com/store/apps/details?id=com.app.wanderly
PROJECT OVERVIEW
Wanderly Stories aims to revolutionize storytelling for children by providing fresh, AI-generated stories every time. The app's intuitive interface and vibrant illustrations make the reading experience educational and entertaining.
MY INVOLVEMENT
As a key developer, I was instrumental in the app's success. My contributions included:
• React Native development: Ensuring a seamless user experience across the web and iOS.
• AWS Amplify Studio configuration and AWS Lambda function scripting for the back end.
• AI integration: Implementing ChatGPT to generate dynamic stories.
• UI/UX design: Collaborating on an intuitive and appealing interface.
• Testing and debugging: Ensuring smooth and efficient app performance.
• Deployment: Managing the launch and updates for both platforms.
My expertise and dedication brought this innovative project to life, offering children a magical storytelling experience.
iOS app: https://apps.apple.com/us/app/wanderly-stories/id6475022201?platform=iphone
Android app: https://play.google.com/store/apps/details?id=com.app.wanderly
Boatsetter | Boat Rental Community
https://www.boatsetter.com/The number one boat owner and rental application product for web and mobile where I developed the web application with Next.js and the iOS and Android mobile applications with React Native. I used a REST API for back-end communication and performed unit testing with Jest.
YouSound | Music Streaming and Shopping Application
https://apps.apple.com/us/app/yousound/id1452078262A React Native-based iOS music album and shopping application where I developed the app from scratch using my experience in music players, audio streaming play, Stripe payment integration, shopping implementation, and REST API integration.
React Native Mobile App for NowYouKnow Neuro
https://nowyouknowneuro.com/A React Native-based mobile app for NowYouKnow Neuro, which is a large healthcare data Q/A application on iOS and Android and I mostly worked as a React Native mobile developer for the app and started working from scratch until the successful delivery, by managing all test flight releases and deploying to the Apple app store and Google Play stores as well.
iOS app link - https://apps.apple.com/us/app/nowyouknowmed/id6648798784
Android app link - https://play.google.com/store/apps/details?id=com.app.nowyouknowneuro&pcampaignid=web_share
iOS app link - https://apps.apple.com/us/app/nowyouknowmed/id6648798784
Android app link - https://play.google.com/store/apps/details?id=com.app.nowyouknowneuro&pcampaignid=web_share
ezCater | Mobile Food Delivery Service
https://apps.apple.com/us/app/ezcater-business-catering/id1162865183/A React Native-based mobile food delivery service product for iOS and Android and as the front-end mobile engineer, I worked with React Native tasks, including the REST API client. I also employed test-driven and Agile software development for CI/CD.
Dating App on iOS and Android, React Native Full-stack Development
https://www.redflagsdatingapp.com/React Native-based mobile (iOS and Android) social dating application with a Node.js back end and PostgreSQL. As a mobile full-stack developer, I worked on the front end (React Native) and back end (Node.js and PostgreSQL). I also fixed remaining bug issues and improved functionalities such as socket connection, UI layout fixing, and in-app subscription expiring/canceling issues.
Revel.xyz | Digital Assets Trading App
https://revel.xyz/A React Native-based iOS and Android application for trading media assets such as photos and videos. The app allows users to collect and share minted assets. I used Firebase and GraphQL for the back end. I also implemented an asset creation AI.
StreetEasy | Real Estate
NYC Real Estate web and mobile application to buy, rent, and search properties and based on the client's request, I worked on the project and delivered the MVP version to a software agency as a full-time dedicated developer. I implemented full REST APIs with payment SDKs and included as many options as possible for property rental and sales.
JoinRoost | Financial Deposit Management Next.js App
https://joinroost.com/A Next.js-based financial deposit management web application development. I enabled automatic cash security deposit management with FusionAuth, loyalty, and financial health. Based on the client's request, I implemented a complete product by Next.js, including the OAuth framework (FusionAuth) implemented.
ClipIt | Social Video Game Clips Sharing App
A web and iOS application to share video clips or screenshots from Xbox, Instagram, and other 3rd parties. A full social feature is included with the full video editing feature. Videos or screenshot images can be taken directly from the device or from Xbox, Instagram, Dropbox, and Facebook. I integrated the leaderboard feature fully.
The iOS application link is here: apps.apple.com/us/app/clip-it-community-for-gamers/id151405.4242.
The iOS application link is here: apps.apple.com/us/app/clip-it-community-for-gamers/id151405.4242.
Education
2007 - 2011
Bachelor's Degree in Computer Science and Mathematics
University of Maryland - College Park, Maryland, USA
Skills
Libraries/APIs
React, Google Maps, Google Maps SDK, Stripe, Stripe Connect, Node.js, REST APIs, Stripe API, React Native for Web, OpenAI API, jQuery, AWS Amplify, Shopify API, Tamagui
Tools
Slack, Xcode, Android Studio, Git, GitHub, Jira, TestFlight, Expo, GitLab, Expo.io, Sentry, CircleCI, Figma
Languages
JavaScript, TypeScript, GraphQL, Swift, Objective-C, Java, Kotlin, CSS, HTML, SQL, Python, Go, HTML5
Frameworks
React Native, Jest, Redux, Next.js, Ruby on Rails (RoR), SwiftUI, Tailwind CSS, Cypress
Paradigms
Agile Software Development, Agile, REST, Unit Testing, Agile Project Management, Test-driven Development (TDD), Cross-platform, Search Engine Optimization (SEO), Mobile Development, Continuous Integration (CI), Continuous Delivery (CD)
Platforms
OS X, Firebase, Azure, iOS, Android, Shopify, Mapbox, Amazon Web Services (AWS), Docker, Twilio, Google Cloud Platform (GCP), WordPress, FusionAuth, Web, DigitalOcean
Storage
Cloud Firestore, PostgreSQL, SQLite, MySQL, MongoDB
Other
Computer Science, Android Development, Mobile Apps, Agile Deployment, Cloud, Web Applications, Axios, Front-end, eCommerce, Social Networks, App Submission, Mobile App Development, Progressive Web Applications (PWAs), Full-stack, Back-end, App UX, User Interface (UI), SDKs, APIs, Front-end Development, API Integration, Web Development, User Experience (UX), CI/CD Pipelines, Full-stack Development, App Store, Google Play Store, Android App Development, App UI, Push Notifications, Authorization, RESTFul APIs, In-app Purchase (IAP), Supabase, Music, Audio, Streaming, OpenAI, Chatbots, Machine Learning, ChatGPT API, OAuth, MVP Design, Video Editing, eCommerce APIs, Artificial Intelligence (AI), AWS Amplify Studio, Monday.com, Supabase Auth, Large Language Models (LLMs)
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