Joe is available for hire

Joe Charlier

Verified Expert in Engineering

iOS Developer

Location

Tokyo, Japan

Toptal Member Since

September 8, 2016

Joe is the lead iOS developer for the startup Mango Health in San Francisco. Previously, he has worked at the startups: Tag, Onside Sports, and Beejive. He has also created two of his own apps: Oovium (a visual math sandbox for iPad, iPhone, and Mac) and Aexels. Joe specializes in designing and implementing elegant user interfaces and user experiences.

Mobile App Development Data Visualization Full-stack SQL Java UIKit iOS Native Libraries iOS SDK Mobile Development iOS Mobile Xcode Cocoa Touch Objective-C Swift

Portfolio

Onside Sports

SQL, Swift, Mobile, iOS, Architecture, Technical Leadership, Full-stack...

PayPay

iOS, Kotlin, Kotlin Multiplatform Mobile (KMM), Cocoa, Cocoa Touch...

Mango Health

NoSQL, JSON, Object-relational Mapping (ORM), SQLite, Android Development, Java...

Experience

Object-relational Mapping (ORM) - 20 years SQL - 20 years Java - 20 years iOS - 14 years Cocoa Touch - 12 years Objective-C - 12 years Xcode - 12 years Core Graphics - 12 years

Availability

Part-time

Preferred Environment

GitHub, Xcode, C, iOS, Cocoa Touch, Swift, Mobile, iOS SDK, iOS Native Libraries, JSON

The most amazing...

...thing I've created so far is the functional, object-oriented visual programming language: Oovium.

Work Experience

Lead iOS Developer

2019 - PRESENT

Onside Sports

Converted the iOS client from Objective-C to Swift.
Added a virtual bankroll to the app, tracking users' balance, wins and losses.
Developed a back-end tool for analyzing data and seeking out advantages picks.
Added a correlated picks feature, including developing the full stack of the feature: database, back-end server, API, iOS infrastructure, and UI/UX design.

Technologies: SQL, Swift, Mobile, iOS, Architecture, Technical Leadership, Full-stack, Software Design, Data Visualization, UIKit, iOS Native Libraries, iOS SDK, Git, Slack, Mobile App Development, Mobile Development, Object-relational Mapping (ORM), Cocoa, Cocoa Touch, Leadership, Concurrent Programming, Adobe Photoshop, Core Animation, GitHub, Software Architecture, GCD, JSON, App Development, API Integration, APIs, Mobile Apps

Senior iOS Developer

2021 - 2022

PayPay

Worked on the iOS consumer app team for PayPay, the largest Japanese mobile payments application with 38 million users. I mainly assisted in refactoring their map feature.
Contributed to the app platform team developing a cross-platform module for iOS and Android using Kotlin via Kotlin Multiplatform Mobile.
Analyzed, reviewed, and critiqued the PayPay iOS architecture.

Technologies: iOS, Kotlin, Kotlin Multiplatform Mobile (KMM), Cocoa, Cocoa Touch, Android Studio, Concurrent Programming, Adobe Photoshop, Android Development, GitHub, GCD, JSON, App Development, API Integration, APIs, Mobile Apps

Lead iOS Developer

2014 - 2017

Mango Health

Spearheaded, as the lead iOS developer, the project of rewriting their iOS client from scratch.
Created a thread-safe ORM making interacting with data easy and safe for more junior developers.
Helped redesign the UX of the iOS client to increase ease of use, flexibility, and access to data for the end-user.
Led a team of six iOS developers, mentoring them on programming, coding style, and other more mundane aspects of software development.
Kicked off the rewrite of the Android client to achieve code parity with the new iOS client.
Wrote an SQLite wrapper that interfaced with the ORM in order to create the JSON/NoSQL persistence layer.

Technologies: NoSQL, JSON, Object-relational Mapping (ORM), SQLite, Android Development, Java, GCD, Core Graphics, Swift, Objective-C, iOS, Mobile, Architecture, Technical Leadership, Software Design, UIKit, iOS Native Libraries, iOS SDK, Git, Slack, Jira, Android, Mobile App Development, Mobile Development, Cocoa, Cocoa Touch, Android Studio, Leadership, Concurrent Programming, Adobe Photoshop, Core Animation, GitHub, Software Architecture, App Development, API Integration, APIs, Mobile Apps

Software Developer

2013 - 2013

Onside Sports

Created the data digester for the NFL play-by-play feed in order to convert into consumable data.
Wrote and designed the NFL play-by-play user interface giving users a sense of the game drive-by-drive.
Wrote and designed the Game Alerts screens in order to notify users of changes to upcoming game lines.

Technologies: Java, Objective-C, Mobile, iOS, Full-stack, Software Design, Data Visualization, UIKit, iOS Native Libraries, iOS SDK, Git, Slack, Mobile App Development, Mobile Development, Object-relational Mapping (ORM), Cocoa, Cocoa Touch, Concurrent Programming, Adobe Photoshop, Core Animation, GitHub, GCD, JSON, App Development, API Integration, APIs, Mobile Apps

Software Developer

2002 - 2010

Succinum

Developed Succinum, an accounting application that managed the natural gas transportation business of Kaztex Energy Management. My own company, Aepryus Software, maintained ownership of the Succinum IP.
Wrote a Loom and Java ORM and application server that initially communicated with Oracle but eventually communicated with MySQL. The ORM has connectors for Oracle, MySQL, and SQLite.
Developed Shazaam, a Java web app that allows a developer to define business objects, their properties, and their relationships with one another. It combines that data with code templates to generate both one-time and regeneratable code.
Used my function parsing code instead of hard-coding these algorithms to allow end users to create and modify various invoice calculation algorithms. Succinum required highly complex and flexible invoice generation algorithms.
Kept my collaboration in the project even after Kaztex Energy Management was sold to Constellation, working simultaneously for Aepryus and Constellation. This project provided me the income to work for years on the Oovium project.

Technologies: XML, MySQL, Oracle, Jakarta Server Pages (JSP), HTML, Java, Architecture, Technical Leadership, Full-stack, Web Development, Software Design, Object-relational Mapping (ORM), Concurrent Programming, Adobe Photoshop, Software Architecture, API Integration, APIs

Software Developer

2008 - 2008

Beejive

Designed the UI/UX of the BeejiveIM iOS app. The app was chosen by Apple in an iTunes review as one of the best apps of 2009.
Implemented the UI/UX in Objective-C/Cocoa Touch. Including the creation of many custom views that allowed us to achieve fast scrolling even with complex cells that included text and many images.
Wrote an ORM-wrapped SQLite in order to store local data.

Technologies: iOS, Objective-C, Mobile, Software Design, UIKit, iOS Native Libraries, iOS SDK, Mobile App Development, Mobile Development, Object-relational Mapping (ORM), Cocoa, Cocoa Touch, Adobe Photoshop, Software Architecture, App Development, API Integration, APIs, Mobile Apps

Software Developer

1998 - 2000

Thoughtworks

Worked on Vitria mapping layers used for connecting different enterprise systems.
Wrote a Java Swing/AWT desktop publishing app used by designers to create graphical document templates that could then be used by end users to create finalized documents.
Wrote an HTML graphical component library in Java for generating data intensive web pages.

Technologies: AWT, Swing, HTML, CORBA, Java, Web Development, Adobe Photoshop, Software Architecture, API Integration, APIs

Software Developer

1995 - 1998

Journal Communications

Wrote a MS Access front end and Oracle back end for managing Journal Communications' employee stock ownership program.

Technologies: SQL, ODBC, Oracle, Visual Basic, Microsoft Access, Architecture, Technical Leadership, Full-stack, Software Design, Adobe Photoshop, Software Architecture, API Integration, APIs

Software Developer

1994 - 1995

Real Estate Analysis Corp.

Wrote a document generation application that would combine data from a Sybase database with document templates stored as RTF. The templates could handle loops, conditionals, and even calculations.

Technologies: ODBC, C++, Sybase, PowerBuilder, Software Design, Adobe Photoshop, Software Architecture, API Integration, APIs

Software Developer

1988 - 1992

DCI Marketing

Started programming, during high school, internal systems for a mid-sized company.
Developed a cost-estimating application for determining the cost to produce custom-made, point-of-sale displays.
Created a project management system for managing tasks on projects that crossed departments throughout the company.
Wrote many financial applications for tracking various accounting information.
Developed a commission system that was used to determine compensation for the company's account executives, including a detail laser printer report.
Built an inventory system that would help production order and maintain parts necessary to manufacturer the custom point of sale displays.

Technologies: PCL, VMS, SQL, C, Ingres, Architecture, Technical Leadership, Software Design, Data Visualization, Adobe Photoshop, Software Architecture, API Integration, APIs

Experience

Oovium

I designed and developed the functional object-oriented visual programming language, Oovium.

Oovium is a math sandbox originally designed for the iPhone and iPad but eventually ported to Mac OS.

AepCalc

AepCalc is a reverse Polish notation calculator designed for desktop computers. The original AepCalc was developed in 1997 for Windows machines. An updated version was developed for MacOS in 2012.

Aexels

Aexels is an iPad app and physics thought experiment that explores different aspects of relativity.

Its current iteration includes a cellular automata workshop that allows users to define and animate their own cellular automata using the Oovium visual programming language.

AepGraph

I wrote a function plotting application using Borland C++ Builder. The application plotted 2D and 3D Cartesian, polar, cylindrical, and spherical functions and with the addition of a time variable t, this enabled them to be animated.

Skills

Languages

SQL, Swift, Objective-C, Java, C, C++, PowerBuilder, HTML, XML, Visual Basic, Kotlin

Frameworks

Cocoa Touch, UIKit, iOS SDK, Cocoa, Jakarta Server Pages (JSP), Swing

Libraries/APIs

Core Graphics, iOS Native Libraries, Core Animation, PCL, ODBC, AWT

Tools

Xcode, Slack, Adobe Photoshop, Git, GitHub, Microsoft Access, Android Studio, Jira

Paradigms

Object-relational Mapping (ORM), Mobile Development, App Development, Concurrent Programming, Functional Programming

Platforms

iOS, Mobile, Oracle, MacOS, Android

Other

Software Architecture, Architecture, Technical Leadership, Full-stack, Software Design, Data Visualization, Mobile App Development, API Integration, APIs, Mobile Apps, Leadership, Web Development, GCD, Android Development, VMS, CORBA, Kotlin Multiplatform Mobile (KMM)

Storage

Ingres, NoSQL, MySQL, SQLite, JSON, Sybase

Education

1990 - 1994

Bachelor of Arts Degree in Physics and Math

University of Chicago - Chicago, IL, USA

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