Kieran Crown

Kieran Crown

Senior Mobile & Full Stack Engineer

I build polished, high-quality mobile apps with React Native, Expo, and SwiftUI, backed by deep GraphQL and cloud expertise. I thrive in small, fast-moving teams where I can own the full stack from design to production.

React NativeExpoTypeScriptGraphQLSwiftUI

About

With over 10 years of experience as a software developer, I specialise in building high-quality mobile applications using React Native and Expo. I have delivered products across fintech, payments, and consumer tech, with particular depth in GraphQL-driven architectures and end-to-end ownership of mobile releases. I'm passionate about crafting polished user experiences and thrive in small, fast-moving teams where I can take ownership from feature design through to production.

At a glance

Location
London
Experience
10+ years
Focus
Mobile apps, polished UX, small fast-moving teams
Certification
AWS Certified Developer

Projects

Personal projects where I explore ideas and push my craft

Stash

A polished read-later app with smart reminders

  • Built with native Swift and SwiftUI for a truly polished iOS feel
  • Integrated share sheet extension for seamless link saving from any app
SwiftSwiftUI

Rozzle

A personal music streaming service you control

  • Full-stack music streaming platform with cloud upload and playback
  • Cross-platform mobile app built with React Native
React NativeNext.jsSupabase

Sonar

Truly private ephemeral messaging with WebRTC

  • End-to-end encrypted messaging using WebRTC for true privacy
  • Real-time ephemeral messages that disappear after reading
SwiftSupabaseSocket.ioWebRTC

Experience

Slice Mobile

Full Stack Engineer
Aug 2025Current

Senior full stack engineer in a team of fewer than four, owning both the Expo-based mobile app and the GraphQL orchestration layer integrating with legacy telecom APIs.

  • Own the full Expo mobile app and GraphQL orchestration layer for a telecom product
  • Span feature development, bug fixes, app releases, CI/CD maintenance, and test coverage
  • Serve as primary owner of the mobile codebase, collaborating closely with backend engineers
  • Balance frontend polish with backend integration in a fast-paced, small team environment
ExpoTanStack QueryMaestroAWS

nsave

Design Engineer
Mar 2025Aug 2025

Sole mobile engineer at a digital banking app focused on savings and financial inclusion, driving a significant modernisation effort across the React Native codebase.

  • Owned the full React Native codebase as the sole mobile engineer
  • Migrated the app to the latest Expo SDK and React Native's new architecture
  • Implemented a design system using Shopify Restyle and Reanimated
  • Built CI/CD pipeline in GitHub Actions with integrated Maestro end-to-end tests
  • Reworked state management for improved reliability across financial features
ExpoTanStack QueryMaestroAWS

Bumble Inc

Mobile Engineer
Jan 2024Mar 2025

Worked on Official, a relationship wellness app acquired by Bumble, leading a codebase rewrite and expanding test coverage.

  • Led a full rewrite of a codebase originally built by contractors, improving quality and maintainability
  • Expanded Maestro end-to-end test coverage, improving release confidence and reducing production issues
  • Contributed to sprint planning and worked closely with product to shape the roadmap
  • Consistently brought ideas to improve UX and overall app quality
React NativeGraphQLMaestroFirebase

Utility Warehouse

Software Engineer
Jan 2023Jan 2024

Built mobile features for the cashback and payments team, including leading Apple Pay and Google Pay integration.

  • Led the implementation of Apple Pay and Google Pay, coordinating directly with both companies through certification
  • Built contactless payment acquisition, swipe-based transaction history, and cashback card management features
  • Owned the redesign of the retailer's view and improved transaction list performance
  • Collaborated with design and two engineering teams to build a shared UI component library adopted across multiple apps
React NativeGraphQLDetox

Nagra Media

Software Engineer
Jul 2022Dec 2022

Contributed to the React Native integration layer connecting with existing iOS, Android, and web platforms at a digital media protection company.

  • Contributed to the React Native integration layer connecting with existing native platforms
  • Gained experience in cross-platform development and integrating modern mobile frameworks with established native systems
React Native

Vpress

Full Stack Developer
Jan 2020Jul 2022

Consolidated backend infrastructure and led frontend modernisation at a leading UK WebPrint provider.

  • Migrated from multiple Node.js servers to a unified AWS deployment using Terraform
  • Led frontend modernisation from a legacy Java stack to Next.js
  • Improved performance, maintainability, and developer experience across the platform
Next.jsTerraformAWSGraphQL

Raytheon

Mobile Cloud Engineer
Dec 2019Jan 2020

Worked on mobile cloud engineering initiatives at a major defence and aerospace company, gaining exposure to enterprise-scale cloud infrastructure.

  • Worked on mobile cloud engineering initiatives within a highly regulated environment
  • Gained exposure to enterprise-scale cloud infrastructure and security-focused development practices
  • Obtained AWS Certified Developer certification
TerraformAWSGraphQL

Gravit8

Software Engineer
Sept 2018Dec 2019

Built interactive digital experiences for brands and event organisers at a creative technology agency.

  • Built a company-wide mobile app using React, Cordova, and Node.js
  • Developed an iPad wall installation for clients including TikTok, a system where hundreds of iPads sync to display a single video
  • Each device supported independent interaction and seamless spatial repositioning using QR-based recognition
CordovaReactJSElectronJS

Skills

Mobile

React Native (Expo)Swift / SwiftUIDetox / MaestroJest

Frontend

TypeScript / JavaScriptReactNext.jsTailwind

Backend & Data

GraphQLNode.jsPostgres / MongoDBSupabaseFirebase

Cloud & DevOps

AWSTerraformCI/CD (GitHub Actions)

Tools

XcodeVS CodeAndroid StudioFigmaLinear / JiraAdobe Suite