Grayson Ho, iOS Developer in London, United Kingdom
Grayson Ho

iOS Developer in London, United Kingdom

Member since September 7, 2022
Grayson is a senior iOS engineer experienced in building mobile products with millions of daily active users and consumer products that scale fast. He has worked as a senior mobile developer at some well-known companies contributing to a finance super app at Revolut, a crypto wallet and exchange for Blockchain.com, and a top downloaded note-taking app at GoodNotes. Grayson understands the whole product development process, handling features from the design phase to the public launch.
Grayson is now available for hire

Portfolio

  • Revolut
    Swift 5, Xcode, Software Development, iOS, MacOS, Mobile, Mobile UX...
  • Wombat Exchange
    Solidity, TypeScript, React, Software Development, UI, UX, Node.js...
  • Blockchain
    Swift 5, Software Development, iOS, Xcode, MacOS, Mobile, Mobile UX...

Experience

  • Xcode 5 years
  • Model View Viewmodel (MVVM) 5 years
  • Native Mobile Apps 5 years
  • iOS 5 years
  • Swift 5 5 years
  • RxSwift 3 years
  • SwiftUI 2 years
  • Combine 2 years

Location

London, United Kingdom

Availability

Full-time

Preferred Environment

MacOS, Xcode, Swift 5, iOS, TypeScript, JavaScript, Front-end

The most amazing...

...products I've built are a finance app for Revolut and an educational note-taking app for GoodNotes, constantly ranked as number one in the App Store.

Employment

  • Senior iOS Engineer

    2022 - PRESENT
    Revolut
    • Led an 8-person team to develop a joint accounts feature for the Revolut Retail app, enabling users to spend on a shared digital wallet.
    • Fixed miscellaneous bugs and made minor improvements to the payment transactions feature, resulting in a 99% crash‑free rate for 19 million weekly active users.
    • Improved the developer experience by shipping new components and updates in the design system.
    Technologies: Swift 5, Xcode, Software Development, iOS, MacOS, Mobile, Mobile UX, Mobile UI, RxSwift, SwiftUI, Combine, UI, UX, Mobile Apps, Swift, Android, Native Mobile Apps, Swift 2, Swift 3, Agile Project Management, Product Management, Project Management, Firebase, Test-driven Development (TDD), Atlassian, Jira, iOS SDK, Objective-C, HTML, Front-end, Figma, Flutter, Mobile Development, Full-stack, Model View Viewmodel (MVVM), Project Planning, Requirements Analysis, Product Strategy, UIKit, GitHub, Animation, A/B Testing, Automated Testing, CI/CD Pipelines, Google Cloud Platform (GCP), APIs, Team Leadership, Architecture, Video Chat, React Native, Wireless Protocols, Wireless, Core Data, CircleCI, TestFlight, Docker
  • Senior dApp Engineer

    2021 - PRESENT
    Wombat Exchange
    • Built decentralized applications (DApps) using TypeScript with React and Solidity for smart contracts.
    • Created an analytics dashboard using GraphQL and React to show transaction volumes and summaries.
    • Handled a protocol with over USD$20 million of total value locked and a record of USD$60 million in daily volume transactions.
    Technologies: Solidity, TypeScript, React, Software Development, UI, UX, Node.js, Agile Project Management, Product Management, Project Management, Firebase, Test-driven Development (TDD), MongoDB, Atlassian, Jira, CSS, JavaScript, HTML, Front-end, Prisma, Next.js, Figma, Mobile Development, Full-stack, Project Planning, Requirements Analysis, Product Strategy, GitHub, Animation, A/B Testing, Automated Testing, CI/CD Pipelines, APIs, Team Leadership, Architecture, React Native, CircleCI, TestFlight, Docker
  • iOS Engineer

    2021 - 2022
    Blockchain
    • Led and shipped the new single sign-on feature for the iOS mobile application using SwiftUI, Combine, and the Composable Architecture pattern. It resulted in 41% more sign‑ups and 37% fewer customer support requests.
    • Modularized various crypto transaction features with a Clean Architecture pattern that reduces the CI build time by 24%.
    • Implemented a design system to improve the developer experience, achieving an internal NPS of 4.2 out of 5.
    Technologies: Swift 5, Software Development, iOS, Xcode, MacOS, Mobile, Mobile UX, Mobile UI, RxSwift, SwiftUI, Combine, UI, UX, Mobile Apps, Swift, Android, Native Mobile Apps, Swift 2, Swift 3, Agile Project Management, Product Management, Project Management, Firebase, Test-driven Development (TDD), MongoDB, Atlassian, Jira, iOS SDK, Objective-C, HTML, Figma, AWS RDS, Mobile Development, Full-stack, Model View Viewmodel (MVVM), Project Planning, Requirements Analysis, Product Strategy, UIKit, GitHub, Animation, A/B Testing, Automated Testing, CI/CD Pipelines, Google Cloud Platform (GCP), APIs, Architecture, Wireless Protocols, CircleCI, TestFlight, Docker
  • iOS Engineer

    2020 - 2021
    GoodNotes
    • Led and shipped a notes-sharing platform on iOS to 10 million monthly active users of GoodNotes 5. Worked with RxSwift, CQRS pattern, and conflict‑free replicated data types.
    • Set up CI/CD pipelines for app deployments using Fastlane and Circle CI.
    • Introduced a release cadence framework that boosted team‑wise productivity.
    Technologies: Swift 5, Software Development, Xcode, iOS, MacOS, Mobile, Mobile UX, Mobile UI, RxSwift, SwiftUI, Combine, UI, UX, Mobile Apps, Swift, Native Mobile Apps, Swift 2, Swift 3, Agile Project Management, Product Management, Project Management, Firebase, Test-driven Development (TDD), MongoDB, Atlassian, Jira, iOS SDK, Objective-C, HTML, Figma, AWS RDS, Mobile Development, Full-stack, Model View Viewmodel (MVVM), Project Planning, Requirements Analysis, Product Strategy, UIKit, GitHub, Animation, A/B Testing, Automated Testing, CI/CD Pipelines, APIs, WebRTC, Architecture, Wireless Protocols, Wireless, Docker

Experience

  • Quintics
    https://testflight.apple.com/join/61g11YYa

    A financial portfolio application that allows users to connect to their stock exchange, crypto exchange, and decentralized wallet accounts and summarize asset information in user‑friendly dashboards.

    I am the founder and developer of the application.

  • Wombat Exchange
    https://app.wombat.exchange/

    Wombat Exchange is a multi-chain stable-swap platform that allows users to swap stable coins at minimal slippage and stake at maximum yield.

    I've contributed to the project as a DApp engineer, frequently interacting with smart contract developers.

  • Cryptocurrency Price Tracker
    https://github.com/graysonhyc/BraveWalletHack

    An iOS mobile app built with SwiftUI and The Composable Architecture (TCA). Users can track real-time crypto-currency prices and their daily percentage changes. The price data is fetched from the CoinGecko API.

  • Conflict-free Replicated Data Type in Python
    https://github.com/graysonhyc/lww_elements_set_py

    Implemented a last-write-wins (LWW) element set data structure and an operation-based conflict-free replicated data type (CDRT) in Python. A test suite was also included to test various CDRT properties, i.e., commutativity, associativity, and idempotence.

Skills

  • Languages

    Swift 5, TypeScript, Swift, Swift 2, Swift 3, CSS, HTML, Dart, Objective-C, JavaScript, Solidity, Python 3, Go
  • Frameworks

    SwiftUI, iOS SDK, Flutter, UIKit, Angular, Next.js, React Native, Core Data
  • Libraries/APIs

    React, RxSwift, Node.js, WebRTC
  • Tools

    Xcode, GitHub, Atlassian, Jira, Figma, CircleCI, TestFlight, Prisma
  • Paradigms

    Model View Viewmodel (MVVM), Agile Project Management, Mobile Development, Requirements Analysis, Test-driven Development (TDD), Automated Testing
  • Platforms

    MacOS, iOS, Mobile, Android, Firebase, Google Cloud Platform (GCP), Docker
  • Industry Expertise

    Project Management
  • Other

    Mobile Apps, Native Mobile Apps, Product Management, Front-end, Project Planning, Product Strategy, APIs, Architecture, Combine, UI, UX, AWS RDS, Full-stack, Animation, A/B Testing, CI/CD Pipelines, Team Leadership, Video Chat, Wireless Protocols, Data Structures, Wireless
  • Storage

    MongoDB

Education

  • Bachelor's Degree in Computer Science
    2016 - 2020
    University of Hong Kong - Pokfulam, Hong Kong
  • Student Exchange Program in Computer Science
    2018 - 2019
    Yale University - New Haven, CT, USA

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