Jesus Guerra
Verified Expert in Engineering
iOS Developer
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, and social media. His passion for iOS development, commitment to on-time delivery, and unwavering pursuit of top-notch code sets 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.
Portfolio
Experience
Availability
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
Waydger Holdings, LLC
- Architected and implemented the Waydger iOS app from prototype to launch-ready state, focusing on UI development using UIKit and MVVM architecture with RxSwift.
- Designed custom UI components with Core Graphics, ensuring a seamless and visually appealing user experience.
- Integrated Twilio Conversations Client to enhance app functionality.
- Implemented Firebase Analytics, Crashlytics, and Messaging for robust app monitoring and user engagement.
- Configured Fastlane for automated release processes, improving deployment efficiency.
- Collaborated with the tech lead to enforce business rules and ensure clean, up-to-date, and bulletproof code.
- Enhanced user engagement through intuitive interfaces and snackable prediction games on diverse topics.
Mobile iOS Developer
Goalvy LLC
- Architected and implemented the Goalvy app using UIKit, MVVM, Combine, and Coordinators for seamless navigation and efficient code management.
- Designed and developed a user-friendly interface without using storyboards or XIBs, focusing on code-based UI development for better performance and maintainability.
- Set up Firebase Authentication to manage user login and account creation, ensuring secure access and data protection.
- Configured Firebase Firestore for secure data handling, including journaling, notes, and to-do lists, ensuring users' data privacy with custom Firebase security rules.
- Utilized Firebase Storage for image management, enabling users to store and retrieve images securely.
- Built a custom in-app purchase module without third-party dependencies, enabling users to subscribe to premium features with seamless transaction handling.
- Integrated Apple UICalendarView for effective schedule management and PencilKit for hand-drawn notes, enhancing user experience with intuitive interfaces.
- Implemented Firebase Analytics and Crashlytics to gather user insights and track app performance, facilitating data-driven improvements and ensuring app stability.
- Managed the entire app submission process, leveraging extensive experience with Apple's review procedures to publish Goalvy on the App Store successfully.
iOS Developer
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.
iOS Swift Developer
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.
Mobile Developer (iOS)
VEGA Global Corporation
- Conducted thorough research to explore and evaluate alternative chat module solutions for the app, considering various features and functionalities.
- Contributed to the 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.
Senior iOS Developer
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.
Senior iOS Developer
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.
Senior iOS Developer
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.
Senior iOS Developer
Pretty Shell
- 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.
Lead iOS Developer
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.
Lead iOS Developer
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.
Lead iOS Developer
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.
Senior iOS Developer
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.
Senior iOS Developer
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.
Senior iOS Developer
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.
Senior iOS Developer
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 UIActivityViewController, 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.
Senior iOS Developer
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.
Senior iOS Developer
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.
Experience
Goalvy: Planner & Life Coach
https://www.goalvy.com/I also incorporated wellness tracking features and resources tailored for healthcare professionals, ensuring comprehensive user support. Utilizing Firebase, I managed secure data handling with Firestore and Storage, configured custom security rules, and implemented Firebase Authentication for secure user login. Additionally, I developed a custom in-app purchase module for subscription management and integrated Firebase Analytics and Crashlytics to gather user insights and track app performance. My efforts culminated in the successful submission and publication of Goalvy on the App Store.
Pretty Shell iOS App
https://app.prettyshell.com/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/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 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
Note: I worked from the first version until v1.9.1, posted in November 2017.
Daily Spot
Note: I worked on it from the first version until v3.5, posted in August 2017.
CannonBall
7 Minute Prayer Challenge
Paktor
https://apps.apple.com/mx/app/paktor-make-new-friends/id654972611?l=enPatrolife
Proptia
https://apps.apple.com/mx/app/proptia/id1547519301• 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.
Waydger App
https://apps.apple.com/us/app/waydger/id1477057954Education
Bachelor's Degree in Computer Systems Engineering
Technological Institute of Hermosillo - Sonora, Mexico
Skills
Libraries/APIs
RxSwift, CocoaPods, SnapKit, REST APIs, Facebook SDK, PromiseKit, Alamofire, Google Maps SDK, Firebase iOS SDK, Google+ iOS SDK, Stripe, Apple Subscriptions, Core Graphics, Sockets
Tools
TestFlight, Xcode, Fastlane, Jira, SwiftLint, Crashlytics, Zeplin, Figma, CircleCI, iOS Instruments, GitHub, Confluence, Git, Grand Central Dispatch
Languages
Objective-C, Swift, GraphQL
Frameworks
UIKit, RealmSwift, MapKit, iOS SDK, Core Location, Combine, SwiftUI, Event Kit, Core Data
Paradigms
Scrum, Model View ViewModel (MVVM), Agile, iOS UI Design
Platforms
iOS, Apple, Firebase, Amazon Web Services (AWS), WatchOS
Storage
Realm, Data Integration
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, Mobile Apps, Coordinator Pattern, Apple Pencil, Event Calendars, Product Management, Coding, Programming, Design Systems, Analytics
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