Joel Frank
Verified Expert in Engineering
Mobile Application Developer
São Tomé de Covelas, Portugal
Toptal member since December 26, 2019
With a PhD in computer science and over 18 years of experience creating mobile applications, Joel has a passion for creating flawless user interfaces and applications that exceed expectations. In addition, his knowledge of databases and back-end requirements gives him a deep understanding of an application's complete architecture.
Portfolio
Experience
- iOS - 17 years
- Android - 12 years
- Amazon Web Services (AWS) - 8 years
- Swift - 7 years
- SOLID Principles - 6 years
- Flutter - 5 years
- Node.js - 3 years
- Augmented Reality (AR) - 2 years
Availability
Preferred Environment
Android, iOS, Mobile App Development, User Experience (UX), Flutter, SwiftUI, SOLID Principles, Cross-platform App Development
The most amazing...
...project was leading a diverse, distributed team to not only meet all strategic goals for the year but do so while maintaining a 47% retention rate for the app.
Work Experience
Lead Flutter Developer | AR Engineer
Kilsar, Inc.
- Architected and implemented a Flutter-based augmented reality (AR) training application that allowed for solo AR sessions and a shared AR experience by embedding the AR session into a multi-person video teleconferencing (VTC) call.
- Led the joint front- and back-end team effort to define the system architecture's microservices for a modular, reusable, performant, and cost-efficient back end.
- Translated the company's strategic roadmap from long-term deliverables to day-to-day operations for the mobile team while reliably meeting deadline after deadline.
- Maintained the team's focus on quality by continually adapting, improving, and polishing the designs under changing requirements.
Lead Flutter Mobile Engineer
Caterpillar
- Managed the small but highly effective engineering team that revolutionized how a Fortune 50 company creates and maintains software.
- Created the core Flutter application that became The Cat App—Caterpillar's central flagship mobile application (Apps.apple.com/us/app/cat-app-fleet-management/id1258931644).
- Developed and evaluated a single application side-by-side against three frameworks: Kotlin Multiplatform Mobile (KMM) with Native SwiftUI, React Native, and Flutter.
- Mentored several team members, from being on the verge of termination to being senior, reliable engineers who now help to drive the team's vision and mentor others.
- Transformed the team's strategic roadmap into actionable sprint plans while meeting the ever-changing requirements of the company's product owners and stakeholders.
Lead Mobile BLE Engineer
Bleu Tech Enterprises, Inc.
- Designed and implemented core BLE libraries for merchant and client, iOS, Android, and UWP, to facilitate encrypted payment transactions via Bluetooth.
- Optimized the BLE bandwidth while allowing messages of arbitrary size in multiple communication channels.
- Coordinated with a diverse team spanning three continents to meet all project milestones ahead of schedule.
CTO | Lead Engineer
Dr Lullaby
- Assisted in writing research grant proposals for the NSF, documenting the application's innovative approaches toward sleep therapy.
- Revamped the existing system architecture to improve performance, maintainability, and scalability.
- Contributed to guide the long-term vision of the project.
Co-founder | Lead Engineer
GroupTing
- Co-led a small team to design and implement a web-based, group coordination application that utilizes a PostgreSQL database supporting a Grails-based server with an AngularJS-based client.
- Managed a remote quality assurance team to provide detailed testing results in time with a rapid development and deployment schedule.
- Worked in coordination with the marketing team to provide agile-based user feedback—a development cycle that resulted in an efficient and responsive product development strategy that was in line with users’ needs.
Senior Software Engineer
Ipsy
- Designed and developed Ipsy’s iOS mobile application that services thousands of users and receives an overall five-star rating (a link to the app can be found in my Experience section).
- Created a novel interface allowing the mobile and web applications to seamlessly communicate.
- Assisted with mentoring junior engineers by teaching them proper engineering techniques and assimilating them into Ipsy's culture.
Development Engineer
Applied Signal Technology
- Designed, implemented, and maintained a Qt-based graphics library that allowed the user to view and manipulate numerous STM-256 signals down to the sub-VGC level in real-time.
- Developed and maintained a multithreaded C++ client/server application for signal analysis to continually meet the customer’s evolving requirements. Communication between the client and the server was done via CORBA.
- Manipulated SDH and PDH signal structures to perform various operations on the information in the data streams.
- Conducted design and code reviews for all team members in an effort to both improve the product as well as guide junior members of the team.
Experience
Cat® App: Fleet Management
I was responsible for leading the team as well as personally responsible for 100% of the iOS codebase.
Ipsy's iOS Mobile Application
https://apps.apple.com/us/app/ipsy-beauty-makeup-tips/id1016673544Draw Together
Risk Runner
Education
PhD in Computer Science
University of California, Santa Cruz - Santa Cruz, CA, USA
Master of Science (MSc) Degree in Computer Science
San Jose State University - San Jose, CA, USA
Bachelor of Science (BSc) Degree with Honors in Computer Science
San Jose State University - San Jose, CA, USA
Skills
Libraries/APIs
HealthKit, Core Image, AVKit, Firebase iOS SDK, Firebase Android SDK, SpriteKit, Core Animation, REST APIs, iOS Native Libraries, Auth, Camera API, ReactiveX, CocoaPods, Facebook API, Fitbit API, Node.js, RxSwift, Android API, Plaid API, Stripe, React, Core Graphics, WebRTC
Tools
Apple HealthKit, Xcode, Interface Builder, Auto Layout, Firebase Analytics, Git, XML Interface Builder (XIB), iTunes Connect, Apple Push Notifications, Fastlane, Android Studio, Sirikit, Firebase Cloud Messaging (FCM), Figma, GitHub, Jira, Plaid, Snapchat, Amazon Transcribe, Amazon Cognito, ChatGPT
Languages
Swift, JavaScript, XML, Dart, Java, C++, Python, Objective-C, HTML, CSS, Kotlin, TypeScript, GraphQL, C#
Frameworks
iOS SDK, UIKit, Core Bluetooth, iOS SceneKit, GameKit, Flutter, SwiftUI, Core Location, Android SDK, React Native, ARKit, Core Data, Redux, Combine, Serverless Framework, Riverpod, Swing
Paradigms
Model View ViewModel (MVVM), MVC Design, Model View Controller (MVC), Model View Intent (MVI), Model View Presenter (MVP), Requirements Analysis, Agile, UX Design, Unit Testing, Test-driven Development (TDD), Scrum, Design Patterns, Mobile Development, Dependency Injection, Concurrent Programming, Azure DevOps, HIPAA Compliance, REST, DevOps
Platforms
Bitrise, Mobile, iOS, Android, Firebase, Amazon Web Services (AWS), iAd, Bluetooth Low Energy (LE), Mapbox, Google Cloud Platform (GCP), Keychain, Banuba, Amazon EC2, Unix, Heroku, AWS Lambda, Universal Windows Platform (UWP), Azure, Twilio
Storage
Cloud Firestore, Firebase Realtime Database, MySQL, JSON, PostgreSQL, MongoDB, Data Synchronization, Amazon S3 (AWS S3), Realm, Azure Cloud Services
Industry Expertise
Telecommunications
Other
APIs, Models, Model View, SDKs, Carthage, Code Architecture, Agile Sprints, Architecture, Technical Leadership, Leadership, Bluetooth, Team Leadership, UI Testing, Apple Design, Mobile App Development, API Integration, User Experience (UX), UI Animation, User Interface (UI), Mobile Apps, Payment Gateways, SOLID Principles, Front-end Development, Mobile UI, Mobile UX, iPad, Location Services, Mobile Architecture, Apps, Software Design, Mobile Applications, Cross-platform App Development, Silent Push Notifications, Consumer-facing Products, BloC, Mobile Streaming, Firebase Cloud Functions, AVFoundation, Networking, Full-stack, CTO, WebSockets, Payment APIs, CI/CD Pipelines, Augmented Reality (AR), Lambda Functions, Serverless, Fintech, Mobile Banking, Technical Architecture, eCommerce, Video Streaming, VoIP, GPS, Internet of Things (IoT), Streaming, Identity & Access Management (IAM), Application Security, Security, Online Payments, Social Networks, Videos, Large Language Models (LLMs), Image Processing, OAuth, Kotlin Multiplatform, Front-end, Back-end, Reinforcement Learning, Elliptic Curve Cryptography, Kotlin Multiplatform Mobile (KMM), Animation, Algorithms, Google Fit, SVG Animation, Dashboards, Cryptocurrency Wallets, Mobile Wallet, Audio Streaming, PCI Compliance, SSL, SSL Certificates, Artificial Intelligence (AI), Data Modeling, OpenAI, Audio Processing
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring