Jesus Guerra, Developer in Hermosillo, Mexico
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Jesus Guerra

Verified Expert  in Engineering

iOS Developer

Location
Hermosillo, Mexico
Toptal Member Since
February 20, 2013

Jesus is a seasoned iOS Engineer with 12+ years of experience spanning various industries, including health, fitness, entertainment, banking, social media, and more. His passion for iOS development, commitment to on-time delivery, and an unwavering pursuit of top-notch code set him apart. Jesus's expertise in the Apple approval process ensures a smooth development journey. He collaborates closely with clients, defining requirements and crafting design documents.

Availability

Part-time

Preferred Environment

GitFlow, Xcode, Swift, Objective-C, iOS, CocoaPods, RxSwift, Model View ViewModel (MVVM), iOS Design Guidelines, iOS App Design

The most amazing...

...thing I've done was deliver a complex sports app under tight deadlines, showcasing my ability to excel under pressure and deliver outstanding results.

Work Experience

iOS Developer

2024 - 2024
Udacity
  • Delivered a set of course exercises on networking and concurrency for iOS apps and iOS application data with SwiftData, demonstrating proficiency in both theoretical concepts and practical application.
  • Created exercises that integrated and configured NetworkMonitor to provide real-time feedback on network connectivity.
  • Developed and implemented asynchronous networking solutions using Swift's async/await pattern in the exercises.
  • Utilized SwiftData to manage complex data models and perform efficient data operations in the exercises.
  • Developed interactive user interfaces using SwiftUI and integrated them with back-end data sources in the exercises.
  • Communicated project requirements, progress updates, and feedback to ensure alignment with client expectations and project milestones.
Technologies: Swift, SwiftUI, Networking, REST APIs

iOS Swift Developer

2024 - 2024
Sober Dating LLC
  • Conducted thorough analysis of SoberDating application functionality, identifying areas for improvement and implementing updates to enhance user experience and streamline operations.
  • Addressed bug reports promptly and effectively, resulting in an increase in app stability and readability and a decrease in app crashes over a month.
  • Ensured compliance with the App Store guidelines for privacy policies and terms of use, leading to successful approval of app updates in the App Store.
  • Refined UI elements based on user feedback to facilitate the integration of new features and updates.
Technologies: iOS, Swift, Firebase, TestFlight, GitHub, SwiftUI

Mobile Developer (iOS)

2023 - 2023
VEGA Global Corporation
  • Conducted thorough research to explore and evaluate alternative chat module solutions for the app, considering various features and functionalities.
  • Comprehensive documentation of research findings, presenting a clear overview of the pros and cons of each potential chat module.
  • Developed a robust Telegram-like prototype to enhance the app's messaging capabilities, offering a familiar and user-friendly chat experience.
  • Implemented significant improvements to the app's functionality based on research insights, ensuring a more robust and versatile platform.
Technologies: iOS, Swift, Xcode, SDK Development

Senior iOS Developer

2023 - 2023
Zed Financial
  • Collaborated with the client's team, significantly boosting the development pace to ensure an on-time release.
  • Rectified UI bugs and code-related issues promptly, enhancing the overall stability and performance of the iOS application.
  • Followed Figma designs meticulously to implement general UI enhancements, improving user interface and experience.
  • Conducted thorough code cleaning and refactoring, leading to a more maintainable and efficient codebase.
  • Leveraged the power of Combine to dynamically update the UI, improving the app's responsiveness and data handling capabilities.
  • Utilized Swift code and Auto Layout techniques to generate reusable UI components, expediting future development efforts.
  • Actively engaged in code reviews on GitHub, providing valuable feedback to peers and fostering a culture of continuous improvement.
  • Facilitated seamless collaboration with the client's team, ensuring effective communication and alignment on project goals.
  • Shared expertise and best practices with team members, supporting their professional growth and development.
  • Actively participated in brainstorming sessions, contributing innovative ideas to improve app functionality and user experience.
Technologies: Swift, UIKit, iOS, Combine, iOS SDK, Firebase, Figma, TestFlight, Core Location, SnapKit, Apple, REST APIs

Senior iOS Developer

2022 - 2022
Splits
  • Worked closely with the client to define project requirements, resulting in clear design documents and technical specifications.
  • Conducted accurate estimations for feature gathering, providing valuable insights into project timelines and resource allocation.
  • Developed the iOS MVP app from scratch, transforming wireframes, mockups, and Figma designs into a fully functional application.
  • Utilized MVVM and RxSwift as the central design architecture, resulting in a scalable and maintainable codebase.
  • Built the UI using Swift UIKit, creating an intuitive and visually appealing user interface.
  • Utilized Realm, enhancing data storage and manipulation.
  • Continuously updated the technical documentation, ensuring it remains accurate and accessible to the client.
Technologies: Swift, iOS, RxSwift, Fastlane, Figma, RealmSwift, Realm, Mobile Architecture, Social Media Apps, Model View ViewModel (MVVM), iOS SDK, TestFlight, Core Location, AVFoundation, UIKit, App Store Acceptance Process, App Store, SnapKit, Apple, iOS Guides, Mobile App Development, Scrum

Senior iOS Developer

2021 - 2022
Proptia
  • Normalized transitions between screens to make the app flow more in line with the native screen presentations.
  • Squashed several bugs and made code changes to improve the app performance.
  • Updated and enhanced UI screens based on the given Zeplin design.
  • Integrated Firebase SDK: Analytics and Crashlytics.
  • Reworked screens to reuse components and enhanced the ease of use of the controllers.
  • Created lanes using Fastlane to automate build uploads to TestFlight.
  • Collaborated in the API requirements creation and documentation for the new app modules.
  • Consumed new endpoints to make the UI react to some server configuration, either showing or hiding user actions inside the app.
  • Updated some deprecated frameworks and gave full support to iOS 14.
Technologies: Fastlane, UIKit, iOS, CocoaPods, Swift, Firebase iOS SDK, Crashlytics, Zeplin, Location Services, Mobile Architecture, iOS SDK, App Store Acceptance Process, App Store, SnapKit, Apple, iOS Guides, Mobile App Development, SDK Development, REST APIs

Senior iOS Developer

2019 - 2021
Pretty Shell
  • Successfully initiated the app development process from scratch, implementing MVVM with RxSwift as the main design architecture, laying a solid foundation for future scalability and maintainability.
  • Coded and configured essential core architecture layers, including networking, data processing, and presentation, ensuring a robust and well-organized codebase.
  • Significantly improved API calls in the network layer by leveraging Alamofire and RxSwift, resulting in enhanced app performance and faster data retrieval.
  • Integrated the Stripe SDK to efficiently manage the entire payments module, providing users with a secure and hassle-free payment experience.
  • Implemented Realm in the data processing layer to proficiently store and manipulate user-generated and server-consumed data, improving data handling and storage efficiency.
  • Built the app's user interface using a combination of storyboard, XIBs, and code-only components, resulting in an intuitive and visually appealing user interface that adapts well to various device sizes.
  • Ensured the UI components were designed and optimized for responsiveness, delivering a consistent user experience across different iOS devices.
  • Actively collaborated with cross-functional teams, participating in meetings, code reviews, and knowledge-sharing sessions, fostering a cohesive and productive work environment.
  • Maintained comprehensive technical documentation, facilitating knowledge transfer and assisting future development and maintenance.
Technologies: RealmSwift, Firebase iOS SDK, Google+ iOS SDK, Model View ViewModel (MVVM), GitFlow, MapKit, Realm, Jira, SwiftLint, Fastlane, Xcode, Swift, iOS, SnapKit, Scrum, Stripe, RxSwift, Alamofire, Location Services, Mobile Architecture, iOS Video, Firebase, Social Media Apps, Figma, iOS SDK, TestFlight, Facebook SDK, Core Location, UIKit, App Store Acceptance Process, App Store, Stripe Subscriptions, Apple, iOS Guides, Mobile App Development, Amazon Web Services (AWS), SDK Development, REST APIs

Lead iOS Developer

2018 - 2019
VarageSale
  • Migrated the codebase from Swift 3 to Swift 4 and refactored and updated the architecture from MVC to MVVM with RxSwift.
  • Added support for iPhone X along with multiple stability and performance fixes.
  • Integrated Firebase SDK, including analytics, AdMob, and messaging.
  • Configured the integration server with Fastlane on CircleCI.
  • Updated the UI to consume new endpoints to display new deals.
Technologies: RealmSwift, Firebase iOS SDK, Google+ iOS SDK, Model View ViewModel (MVVM), Carthage, GitFlow, Realm, Jira, SwiftLint, Fastlane, Xcode, Swift, iOS, CocoaPods, R.swift, Alamofire, RxSwift, CircleCI, Location Services, Firebase, Lottie, Social Media Apps, Figma, iOS SDK, TestFlight, Facebook SDK, UIKit, Apple, Mobile App Development, Scrum, REST APIs

Lead iOS Developer

2017 - 2018
Banco Itaú
  • Defined the app architecture and added user analytics.
  • Configured the integration server in CircleCI and Fastlane.
  • Coded most of the network and business layer for the app.
  • Developed several modules, including disputes, profiles, and transaction history.
  • Integrated a third-party encryption tool into the app.
Technologies: Firebase iOS SDK, GitFlow, SwiftLint, Fastlane, Xcode, Swift, iOS, CocoaPods, Crashlytics, CircleCI, Location Services, Mobile Architecture, Firebase, iOS SDK, TestFlight, Core Location, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, Scrum, SDK Development

Lead iOS Developer

2017 - 2017
Sara
  • Started the app from scratch and helped to document the API data contract.
  • Set core architecture and core functionality to all API and user interactions.
  • Boosted API consumption with PromiseKit and Alamofire.
  • Used Core Location and MapKit to pinpoint locations near the app user.
  • Added a data layer to process all API information.
  • Contributed from the very first version until v1.9.1 posted in November 2017.
  • Configured CircleCI server for automated builds with Fastlane.
Technologies: Firebase iOS SDK, GitFlow, SwiftLint, Fastlane, Xcode, Swift, iOS, CocoaPods, Crashlytics, SnapKit, R.swift, Alamofire, PromiseKit, CircleCI, Location Services, Mobile Architecture, Video Streaming, Firebase, iOS SDK, TestFlight, AVFoundation, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, Scrum, SDK Development

Senior iOS Developer

2016 - 2017
Docler USA, LLC
  • Implemented multiple user interface updates meticulously, enhancing the app's overall look and feel.
  • Upgraded social network sharing for improved engagement.
  • Introduced a new video overlay for an enhanced experience in both portrait and landscape modes, enhancing the user experience.
  • Added key features like email and Google login, user block/unblock, and enhanced notifications.
  • Resolved a range of bugs diligently, ensuring the application's stability and smooth operation.
Technologies: GitFlow, SwiftLint, Fastlane, Xcode, Swift, iOS, CocoaPods, Facebook SDK, iOS SDK, UIKit, Apple, Mobile App Development, REST APIs

Senior iOS Developer

2016 - 2017
Daily Spot
  • Initiated the development of the fitness assistant app from scratch, adopting Swift as the primary design architecture to ensure a streamlined and efficient user experience.
  • Utilized Realm, a robust database framework, to efficiently store and manage user-generated data and content retrieved from the server, optimizing data processing and accessibility.
  • Employed a versatile combination of storyboard, XIBs, and code-only components to craft a user-friendly and responsive user interface, providing users with an intuitive and visually appealing experience.
  • Enhanced API calls in the network layer by leveraging PromiseKit with Alamofire, resulting in improved network performance, faster data retrieval, and overall app efficiency.
  • Implemented and managed a dedicated module for handling app subscriptions and integrating in-app Apple purchases, simplifying the user subscription process.
  • Developed a specialized player module centered around AVFoundation to enable audio streaming for fitness routines, enhancing the fitness app's interactivity and providing users with comprehensive audio guidance.
Technologies: RealmSwift, Firebase iOS SDK, In-app Purchases, GitFlow, Realm, SwiftLint, Fastlane, Xcode, Swift, iOS, CocoaPods, Crashlytics, SnapKit, Alamofire, PromiseKit, Location Services, Mobile Architecture, Video Streaming, iOS Video, Social Media Apps, Figma, iOS SDK, TestFlight, Facebook SDK, Core Location, AVFoundation, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, SDK Development, REST APIs

Senior iOS Developer

2016 - 2016
7 Minute Prayer Challenge
  • Improved the overall stability and performance of this iOS app, ensuring a smoother and more responsive user experience.
  • Developed a custom player module that encapsulates the AVFoundation framework, enhancing media playback and control.
  • Introduced a dedicated module to seamlessly track users' prayers and synchronize their progress across multiple devices, promoting a consistent and organized prayer routine.
  • Addressed and rectified various general bugs while also making substantial code enhancements, optimizing the app's reliability and maintainability.
Technologies: Xcode, Objective-C, CocoaPods, iOS SDK, TestFlight, AVFoundation, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, Scrum, REST APIs

Senior iOS Developer

2014 - 2016
CannonBall
  • Crafted new layouts with care and addressed UI issues to enhance the overall user experience and ensure visual aesthetics.
  • Utilized EKEventStore for seamless event synchronization within the calendar, providing users with organized and synchronized event data.
  • Introduced iOS enhancements, implementing new features and functionalities to keep the app up-to-date with the latest iOS standards.
  • Conducted a series of performance improvements to optimize the app's speed and responsiveness.
  • Implemented native sharing capabilities using UIActivity​View​Controller, facilitating user-driven content sharing on social platforms.
  • Conducted extensive code refactoring to improve code quality and maintainability while resolving critical bugs.
  • Handled REST API iterations for data consumption and synchronization, ensuring smooth data flow between the app and the server.
Technologies: Xcode, Objective-C, Crashlytics, TestFlight, Scrum, Location Services, Video Streaming, iOS Video, Google Maps SDK, Social Media Apps, iOS SDK, Facebook SDK, Core Location, AVFoundation, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, REST APIs

Senior iOS Developer

2013 - 2013
Paktor
  • Made iOS7-compatible enhancements.
  • Applied a new layout and solved UI issues.
  • Refactored code and fixed bugs.
  • Wrote automation test scripts.
  • Worked on localization.
Technologies: Xcode, Objective-C, Location Services, iOS Video, Google Maps SDK, Social Media Apps, iOS SDK, Facebook SDK, Core Location, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development, REST APIs

Senior iOS Developer

2013 - 2013
Patrolife
  • Created full support for iOS 7.
  • Wrote a submodule to handle "no internet connections" events.
  • Added Russian localization using Localizable.strings.
  • Solved UI issues that cropped up due the new iOS 7 Extended Layout.
  • Improved GPS monitoring.
Technologies: MapKit, Xcode, Objective-C, CocoaPods, Google Maps SDK, iOS SDK, Core Location, UIKit, App Store Acceptance Process, App Store, Apple, iOS Guides, Mobile App Development

Pretty Shell iOS App

https://app.prettyshell.com/
I had the opportunity to create a unique app that connects users looking to rent or lend various articles. Their innovative model blends for-profit and nonprofit concepts, promoting shared profits that benefit the causes chosen by their community. I built the app from the ground up, employing MVVM and RxSwift as the central design architecture.

My role involved coding and configuring essential core architecture layers, including networking, data processing, and presentation, which served as the backbone of the app's structure.

I seamlessly integrated the Stripe SDK to efficiently manage payments, ensuring users had a secure and hassle-free payment experience. In the data processing layer, I harnessed the power of Realm to store and manipulate user-generated and server-consumed data, enhancing data handling and storage efficiency.

UI components were meticulously designed and optimized for responsiveness, guaranteeing a consistent user experience across iOS devices.

Throughout the project, I maintained comprehensive technical documentation, simplifying knowledge transfer and supporting future development and maintenance.

VEGA iOS App

https://vegagem.com/
I undertook a pivotal role focused on enhancing the app's messaging capabilities. My responsibilities encompassed conducting extensive research to identify and evaluate potential alternatives for the chat module. This involved comprehensive documentation of research findings, offering clear insights into the strengths and weaknesses of each option.

Furthermore, I leveraged my technical expertise to develop a Telegram-like prototype, elevating the chat module's functionality and improving user communication.

VarageSale: Buy & Sell

https://www.varagesale.com/
I had the privilege of working at VarageSale, a family-friendly app dedicated to buying and selling new and used items locally. During my time there, I was involved in numerous impactful improvements and introduced new features that elevated the platform's functionality. I revamped the 'Deal' feature, providing a refreshed UI and integrating new endpoints for a seamless user experience.

I configured the integration server with Fastlane on CircleCI to streamline development and ensure reliable releases. The result was a more efficient and consistent development process. My contributions, including the UI updates for displaying new deals and addressing stability and performance concerns, led to quantifiable improvements in user engagement, platform reliability, and overall business success.

Sara: Personal Health Assistant

This app is a personal health assistant where you can schedule medical exams at a particular time in a specific facility based on your geolocation. Sara will provide all the information for the medical exam and will let you know when your results are ready. I started this app from scratch and became the team leader once a new iOS dev joined the team.

Note: I worked from the first version until v1.9.1, posted in November 2017.

Daily Spot

As a solo developer, I embarked on creating a comprehensive fitness assistant app, starting from the ground up. This fitness companion delivers crucial exercise information through illustrated images and audio guidance, ensuring users can work out effectively and access essential details to subscribe to fitness programs.

Note: I worked on it from the first version until v3.5, posted in August 2017.

CannonBall

During my tenure with Cannonball, I was an integral part of the team that transformed traditional calendars into captivating social streaming apps. Cannonball injected large images into calendar events and introduced enticing features like Facebook birthday integration with links to friends' profiles, interactive maps for directions, check-ins, and more.

7 Minute Prayer Challenge

I had the privilege of collaborating on a prayer app, focusing on enhancing its overall performance and stability. This project offered a unique opportunity to work on a spiritual platform, making it accessible and reliable for users. I crafted a custom player module, elevating the media playback experience, and introduced a 'Sync Prayers' module, ensuring users could seamlessly track their spiritual journey across various devices. These enhancements improved the app's functionality and provided a more robust, user-friendly experience. My contributions played a vital role in quantifiable improvements, increasing user engagement, trust, and satisfaction within this spiritual community.

Paktor

https://apps.apple.com/mx/app/paktor-make-new-friends/id654972611?l=en
My general contributions include iOS 7 migration and compatible enhancements, extend messages module by implementing new UI/Layou, improve the match card animation and general UI en enhancements, refactoring and bug fixing.

Patrolife

An app that I helped to update and localize. I implemented full iOS7 support, wrote a submodule to handle internet connection outages, added Russian localization, solved UI issues stemming from the operation system update, and improved GPS monitoring.

Proptia

https://apps.apple.com/mx/app/proptia/id1547519301
I have been involved in several improvements and new features, including:

• Normalized transitions between screens to make the app flow more in line with the native screen presentations.
• Squashed several bugs and made code changes to improve the app performance.
• Updated and enhanced UI screens based on the given Zeplin design.
• Integrated Firebase SDK: Analytics and Crashlytics.
• Reworked screens to reuse components and enhanced the ease of use of the controllers.
• Collaborated in the API requirements creation and documentation for the new app modules.
2002 - 2007

Bachelor's Degree in Computer Systems Engineering

Technological Institute of Hermosillo - Sonora, Mexico

Libraries/APIs

RxSwift, CocoaPods, SnapKit, REST APIs, Facebook SDK, PromiseKit, Alamofire, Google Maps SDK, Firebase iOS SDK, Google+ iOS SDK, Stripe

Tools

TestFlight, Xcode, Fastlane, Jira, SwiftLint, Crashlytics, Zeplin, Figma, CircleCI, iOS Instruments, GitHub, Confluence, Git

Frameworks

UIKit, RealmSwift, MapKit, iOS SDK, Core Location, Combine, SwiftUI

Languages

Objective-C, Swift, GraphQL

Paradigms

Scrum, Model View ViewModel (MVVM)

Platforms

iOS, Apple, Firebase, Amazon Web Services (AWS), WatchOS

Storage

Realm

Other

GitFlow, App Store, App Store Acceptance Process, Mobile App Development, AVFoundation, Location Services, Mobile Architecture, Video Streaming, iOS Video, Social Media Apps, iOS Guides, SDK Development, Architecture, In-app Purchases, R.swift, Carthage, Stripe Subscriptions, Lottie, iOS App Design, iOS Design Guidelines, Development, Audio Streaming, Networking

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