I'm Jonny

I'm Jonny

Software engineer and Product designer

Software engineer and Product designer

I work with ambitious teams to design, build, and launch products that solve real problems.

I work with ambitious teams to design, build, and launch products that solve real problems.

My services

My services

Web

Web

Web apps (SPA/PWA/MPA)

CMS

eCommerce

I build fast, scalable React web applications - from quick updates to existing setups to full new builds. I can tailor solutions for speed, maintainability, or growth.

I build fast, scalable React web applications - from quick updates to existing setups to full new builds. I can tailor solutions for speed, maintainability, or growth.

Mobile

Mobile

React native

Capacitor

I create cross-platform mobile apps. My focus is smooth performance, reliable integrations, and a native user experience across both iOS and Android.

I create cross-platform mobile apps. My focus is smooth performance, reliable integrations, and a native user experience across both iOS and Android.

Design

Design

User research

UX design

Visual design

Usability testing

I design clean, intuitive user experiences from concept to prototype. Combining user research, UX and visual design, I create products that look great, feel effortless to use, and meet real user needs.

I design clean, intuitive user experiences from concept to prototype. Combining user research, UX and visual design, I create products that look great, feel effortless to use, and meet real user needs.

Tools I use to deliver

Tools I use to deliver

This is a subset so please reach out if you have other requirements.

This is a subset so please reach out if you have other requirements.

Development

Development

TypeScript

React & React native

Capacitor

Next js

Node js

Cypress

Design and prototyping

Design and prototyping

Figma

Team/organisation

Team/organisation

Notion

Miro

Atlassian

Communication

Communication

Slack

Loom

Have a project in mind?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

Have a project in mind?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

Have a project in mind?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

Featured Projects

Featured Projects

Biscuit - Mobile App

Biscuit - Mobile App

Led frontend development for Biscuit, a pet wellness app that reached #1 in both Google Play and the App Store, achieving 200,000+ downloads and 60,000+ monthly active users.

Led frontend development for Biscuit, a pet wellness app that reached #1 in both Google Play and the App Store, achieving 200,000+ downloads and 60,000+ monthly active users.

Capacitor, Typescript, Playwright, .NET, Kubernetes, Docker and more

Capacitor, Typescript, Playwright, .NET, Kubernetes, Docker and more

Three screenshots from the biscuit app. One shows the dashboard that shows overall progress, the second is a running live activity where someone is tracing their dog walk and the third is of someone's activity record where they can see their route
Three screenshots from the biscuit app. One shows the dashboard that shows overall progress, the second is a running live activity where someone is tracing their dog walk and the third is of someone's activity record where they can see their route
Three screenshots from the biscuit app. One shows the dashboard that shows overall progress, the second is a running live activity where someone is tracing their dog walk and the third is of someone's activity record where they can see their route

Highlights

Solved complex challenges around background GPS tracking, real-time activity monitoring, and performance optimisation across iOS and Android.

Impact

Delivered a seamless, high-performing interface that supported scale and helped the product achieve top-chart status and strong user retention.

Collaboration

Worked closely with backend engineers, designers, and product stakeholders to refine UX and ensure technical feasibility within tight launch timelines.

Lodgify - Web app

Lodgify - Web app

Helped scale a vacation rental platform by building a high-performance static site generator and open-source UI library, replacing slow legacy systems with a solution that enabled rapid growth.

Helped scale a vacation rental platform by building a high-performance static site generator and open-source UI library, replacing slow legacy systems with a solution that enabled rapid growth.

React, Typescript, Kubernetes, Docker, Node, Cypress and more

React, Typescript, Kubernetes, Docker, Node, Cypress and more

Three screenshots from the biscuit app. One shows the dashboard that shows overall progress, the second is a running live activity where someone is tracing their dog walk and the third is of someone's activity record where they can see their route
Three screenshots from the biscuit app. One shows the dashboard that shows overall progress, the second is a running live activity where someone is tracing their dog walk and the third is of someone's activity record where they can see their route

Highlights

Architected a site generator that powered thousands of property listing websites. Built an open-source UI library enabling external developers to create custom templates. Helped grow the engineering team from 2 to 7 members.

Impact

Transformed a slow, limiting system into a fast, scalable solution that became a crucial part of Lodgify's offering and competitive advantage.

Collaboration

Worked with product and engineering leads to architect the new platform, onboard new team members, and establish patterns for external developer adoption.

Onna - Mobile App

Onna - Mobile App

Co-founder and technical lead for a self-guided therapy app helping people overcome social anxiety and build confidence. Took the product from clinical research to App Store launch.

Co-founder and technical lead for a self-guided therapy app helping people overcome social anxiety and build confidence. Took the product from clinical research to App Store launch.

React Native, Expo, Jest, Supabase and more

React Native, Expo, Jest, Supabase and more

Three screenshots from the Onna app. They show the progress of choosing a trigger situation, working on a trigger situation and then doing a breathing technique
Three screenshots from the Onna app. They show the progress of choosing a trigger situation, working on a trigger situation and then doing a breathing technique
Three screenshots from the Onna app. They show the progress of choosing a trigger situation, working on a trigger situation and then doing a breathing technique

Highlights

Sole technical contributor responsible for the entire product – from translating clinical requirements into intuitive UX/UI, to architecting the full-stack infrastructure, to shipping production-ready apps on iOS and Android. Owned every technical decision and delivery milestone.

Impact

Shipped a complete therapeutic product independently, proving ability to operate autonomously across the full product lifecycle – from understanding complex domain requirements to design to technical execution – without requiring technical support or oversight.

Collaboration

Worked directly with co-founder and clinical psychologists to ensure therapeutic standards whilst maintaining full technical ownership and delivery accountability.

Want to hear about my other projects?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

Want to hear about my other projects?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

Want to hear about my other projects?

I’m currently open to select freelance and consulting projects

Message me

or

Connect on LinkedIn

©2025 Jonny Gwillim. All rights reserved.