Anthony Guay,iOS Engineer

Selected mobile product work

Products I’ve worked on.

A selection from 15+ years across iOS engineering, product leadership, and startups—from high-scale consumer marketplaces to early-stage experiments.

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01

Monzo

At Monzo US, I shaped and built customer-critical mobile experiences for a digital bank serving 15M+ customers. I owned Cash Deposits end to end across iOS and Android. I led mobile engineering, end-to-end testing, and rollout for a high-risk sponsor-bank migration, seamlessly migrating more than 99.9% of customer accounts. I also created a structured product-quality program spanning observability, testing, release safeguards, and systematic bug reduction.

Built with: Swift, TCA, XCTest/XCUITest, E2E testing, CI/CD, Observability, iOS and Android

Open on the App Store ↗
1 / 5
02

Mercari

On a marketplace used by 5M+ monthly iOS shoppers and generating $1B+ in GMV, I was one of three iOS engineers building the app and led multiple large marketplace initiatives. For Bundles, I led architecture and execution across a five-engineer team; the feature drove hundreds of thousands of unit sales and tens of millions in GMV growth in its first quarter. I built across both the Swift/UIKit app and its React Native rewrite. The work combined hands-on implementation with close product and UX collaboration at scale.

Built with: Swift, UIKit, RxSwift, MVVM, XCTest, Protocol Buffers, React Native, TypeScript, Firebase, Sentry, CI/CD

Open on the App Store ↗
1 / 5
03

Chores

Chores is a Swift app I created to make shared household work visible and fair. Partners can add tasks, mark them complete, and see how time is distributed. Firebase handles sign-in, shared data, and real-time updates.

Built with: Swift, UIKit, Firebase, Authentication, Real-time sync, Auto Layout

1 / 5
04

Wonolo Pro

At Wonolo, I owned the consumer app serving 500K+ workers during a period of 300% year-over-year growth and $40M+ in revenue. I then conceived, designed, and launched Wonolo Pro in three months, creating a cross-platform mobile experience for employers to manage their contingent workforce on the go.

Built with: React Native, REST APIs, Authentication, iOS, Android

1 / 6
05

Modde: The Fashion App

Modde was a photo-sharing network for fashion enthusiasts that I co-founded and built on iOS. I shipped 30+ App Store iterations in six months, using rapid releases to evolve the product from likes and comments to emoji reactions and outfit voting. The work spanned camera UX, social interactions, performance, and polish.

Built with: Objective-C, UIKit, Core Data, REST APIs, Camera, Push Notifications, Background work, Animations, Facebook Login

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06

Brainer

Brainer was a real-money trivia app that I conceived, prototyped, and architected with a small mobile team. We shipped a major update every week for 12 weeks, iterating on gameplay, purchases, onboarding, and motion.

Built with: Objective-C, UIKit, Parse, In-App Purchases, Authentication, Networking, Animations

1 / 6
07

Sacred Heart College

For Sacred Heart College, I built a role-aware iOS app that served students, parents, and teachers with different experiences. It brought school news, calendars, and targeted push notifications into a single mobile product connected to the college’s existing WordPress CMS.

Built with: Objective-C, UIKit, Push Notifications, WordPress integration, JSON

1 / 6
08

Lumenpulse

For Lumenpulse, I built a universal iPhone and iPad sales app that turned a large architectural-lighting catalog into a portable presentation tool. Sales teams could browse current products, specifications, and real-world installations, with content kept in sync from the company CMS.

Built with: Objective-C, UIKit, iPhone and iPad, JSON APIs, Maps, Slideshows, Animations

1 / 5
09

Rib ‘N Reef

Rib ’N Reef needed a polished mobile companion for a long-established steakhouse. I built an iOS app that let guests browse the menu, explore photography, and find the restaurant—giving the team a compact marketing and in-venue experience.

Built with: Objective-C, UIKit, Table Views, Maps

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10

Fablab

For a 3D printing company, I built an iOS viewer that opened 3D files on the phone so customers and staff could inspect models before submitting them for print. The project paired a practical workflow with real-time 3D rendering on early iOS hardware.

Built with: Objective-C, OpenGL ES, 3D file handling, Open-source libraries

11

Novo Finance

Novo Finance was a personal stock-tracking app built around live market data. Users could create an account, search tickers, assemble a portfolio, and explore performance through charts—an end-to-end product covering data, persistence, and visualization.

Built with: Authentication, Parse, Yahoo Finance API, Data persistence, Charts

12

AQR

AQR explored augmented reality on iOS before ARKit. The app recognized QR markers through the camera and replaced them with 3D objects in space; it could also generate printable markers for use with those experiences.

Built with: Camera, QR code detection, 3D rendering, REST APIs, Authentication