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Chris Pung - iOS Developer

Boston, MA
October 05, 2020

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Professional Profile

* ***** ** ********** ** iOS Mobile App Development with a total of 5 years in Information Technology

Expertise in Agile SCRUM methodology and familiar with Waterfall/TDD. Worked under 2-3 week sprints with user stories, sprint planning sessions, retrospectives, burn down charts, etc.

5 years’ experience in iOS development with 4 enterprise apps in the app store

8+ years total experience in IT providing development, analysis and support services

Proficient with XCode IDE 6-10 and iOS 7-12+.

Familiar with current practices and standards, including OOP design patterns such as MVC/MVVM, singleton, delegate, observer, factory, KVC and KVO design patterns

Knowledgeable with push notifications. Experience retrieving authorization from users, receiving token from apple and sending to client server. Have worked with attaining .p12 files for both dev./distr. builds; adept at handling received notifications.

Have worked with 3rd-party frameworks such as AFNetworking, Google API, and several others; versed in using Cocoa Pods.

Majority of projects conducted under an agile scrum methodology for development with lots of collaboration; have also experience working with overseas teams.

Comfortable participating in daily standup meetings, weekly code reviews, sprint planning sessions, working with burn down charts and user stories. Normally worked under 2-3 week sprints.

Previously implemented CoreData and SQLite for local and remote data storage; minor experience with iCloud.

Good with pushing, pulling, committing and resolving merge conflicts.

Integrated with Facebook, Twitter, Instagram, and various other social media APIs via third party SDKs and RESTful calls; also utilized Accounts and Social frameworks.

Technical Skills

Programming Languages

Objective-C, Swift (1-5), C, C#, C++, Assembly, SQL, Java,, HTML, CSS

Web Services



Test-Driven Development (TDD),

Continuous Integration,

Unit Test, Functional Test, Scenario Test,

Automated Testing

Testing Tools

XCTest, jUnit

Jenkins, Hudson, Travis, TestFlight, Instruments, Allocations

Various Frameworks

Cocoa Touch, CocoaPods, Social Framework, Firebase, Entity, JSP, JSF, Ant

Version Control Tools

Git and SVN

GitHub, SourceTree, Bitbucket


Microsoft Office Word, Excel, PowerPoint

Design Patterns




SQLite, SQL, MySQL, Firebase, MongoDB


Xcode, Visual Studio, Eclipse, Code::Blocks,


Project Tools

Agile, JIRA, Rally

iOS Development

App Extension, Handoff, Document Picker

AirDrop, TextKit, UIKit, UI Dynamics

Multithreading, Xib Interface Builder, Size Classes, UIKit, CALayers, UIView, Views and View Controllers, Gesture Recognizers

Standard System View Controllers

GCD, NSOperations, EventKit, Adaptive Layout, AutoLayout, UI State Preservation, UIKit, Storyboard, Apple Push Notification Service, Local Notifications, CoreData, Core Location, CoreGraphics, CoreAnimation, Core Bluetooth, MapKit, Location Kit

Professional Experience

March 2020 – Present

United Health Group Optum, Boston, MA

Senior iOS Engineer

The Sparq app provides UHG employees with a mobile hub, providing a variety of helpful features including a daily news feed, directory search for people or facilities, and a new integration with SPREO for wayfinding and submitting repair tickets.

Used Xcode and its built-in simulator to design user interface to the team’s specifications

Worked closely with other Devs, QA, and planners to execute the expected behaviors. (2 iOS, 2 Android, 2 backend, 3 design, 2 QA)

Referenced Zeplin designs as a model for iOS app UI

Used Rally to track stories, pull assets, and update progress

Built and implemented a new payroll calendar feature from scratch

Localized all text in app for international users in Brazil

Reported in daily stand-up meetings with progress of tasks

Worked in 2-week sprints starting on Wednesdays.

Integrated clickable links to maps app

Made buttons link out to external URL

Provided assessment of task difficulty in terms of point values for planning sprint tasks and assignments. (Fibonacci rating)

Provided feedback and improvements to the iOS developer onboarding documentation and procedures.

Assisted other Devs in finding solutions to their tasks.

Effectively communicated with teammates about what was needed and quickly removed blockers to continue work.

Created multiple custom buttons, cells, and interactable items

Restructured placement of features to be more organized and user friendly

Provided features to users based on required profile flags. (if your profile did not have a tag for a feature, you would not be able to access it.)

Worked on custom tab bar for navigation

Integrated FSCalendar cocoapod for payroll calendar, complete with custom date markers for events and a legend.

Worked with SPREO to plan integration of wayfinding features within certain facilities

AUGUST 2018 – March 2020

Avis Budget Group, Parsippany, NJ

Senior iOS Mobile App Engineer

The Avis iOS mobile app offers certain features for users that are exclusive to the app. Features such as auto exchange, upgrade, quick return, auto lock/unlock. The app also provides standard car rental features such as location of nearby stores, and basic information and account management (rewards, payments, receipts, history). The app also includes Roadside Assistance.

Developed the iOS mobile app using iOS 11-12 in Swift 4-4.2 and Objective-C using Xcode 9-10

Made use of various Architectural and design patterns (MVC, MVVM, KVO, Singleton, MVP)

Created classes for architectural variability and usability through subclasses.

Multithreading with both GCD and NSOperation to improve UI performance on main thread.

Utilized GCD/NSOperation multithreading techniques for downloading catalog images of the menu on background thread to not lock up the UI and ongoing animations.

Worked with the design patterns and corporate image to design a useful user-friendly interface for the iOS application.

Worked with Keychain to share sensitive data between applications.

Working with 3rd-party libraries for information exchange and used RxCocoa to manage dependencies.

Consumed RESTful web services using Alamofire with RxSwift with Codable for JSON parsing.

Used Git Repository with SourceTree for iOS code base version control.

Worked on an iOS development team of 5 in an Agile Scrum environment with daily scrums and weekly sprints.

Developed improvements using Core Animation and Core Graphics.

Responsible for enhancing modules including different interfaces.

Implemented Unit Testing of the iOS mobile app, moved the app to production, and helped get App Store approval, then submitted the app to the App Store.

Implemented advanced animation techniques to provide a user-friendly interface.

Developed a responsive user interface that adapted to a wide variety of iOS devices

Developed UI using Storyboards and AutoLayout, Constraints, as per design specifications

SEPTEMBER 2017 – JULY 2018

State Farm, Bloomington, IL

iOS Mobile App Developer III

iOS for State Farm mobile app has a lot of integrated features added such as managing insurance and banking accounts, request roadside assistance, file and track claims, viewing auto insurance ID card and add it to Apple Wallet, and pay with Apple Pay. Users can set custom reminders and notifications, ask Siri to view your insurance card, your claims, or find nearby ATMs. Login with Touch ID, Face ID, or a PIN. Send a text message to the agent.

Created Custom Views to enhance the UI experience using Storyboards and XIBs, with Auto Layout Constraints for dynamic layout.

Using Core Data for data persistency. Worked with Agile development using the SCRUM methodology, attending daily leadership meetings, bi-weekly sprint planning meetings and bringing development strategies to the table for feature implementations.

Attended meetings for requirements with project owners and reviewed project goals and prototypes.

Team size of 6 people. PM, iOS architect, 3 senior dev, 1 backend senior dev; then reduced to 3 developers (2 front end and 1 back end).

Mentored junior developers, oversaw code reviews and collaborated with stakeholders, project manager and quality assurance testers to ensure the performance and usability of the app.

Worked with Atlassian stack for team tools including JIRA and SourceTree for requirements, issues, and bug tracking.

The project team used Git as the code repository with SourceTree GUI for versioning to manage commits and changes.

HockeyApp utilized for crash analysis and solving issues.

Bugs resolved using a combination of NSLog, LLDB statements, Breakpoints, Instruments, and Crash Logs.

JULY 2016 – AUGUST 2017

Express Scripts Holding, St. Luis, MO

iOS Mobile App Developer II

Features of this iOS app including finding a preferred pharmacy based on insurance plan and locate nearby stores. Users can order refills, track orders, make automatic refills and access ID card.

Apple Push Notification Service (APNS) used for user notification of pharmacy orders ready and refill reminders.

Integrated RESTful web services with custom APIs to access database.

Implemented MapKit for iOS for locating nearby stores.

Used Codeable to parse JSON objects from server to the iOS mobile app.

Coded the app in Swift with RxSwift on an MVVM architecture and various design patterns.

Performed review of iOS entire code base and participated in peer-to-peer code reviews. GCD and NSOperations used to make asynchronous service calls for background processing

Supported multiple screen resolutions and orientation

Integrated with SQLite for data persistency

Worked with Restful web services to exchange information using Alamofire with GCD for concurrency.

Bugs resolved using a combination of NSLog, LLDB statements, Breakpoints, Instruments, and Crash Logs

Created and optimized the infrastructure for the internal SQLite database and NSUserDefaults data persistence.

Transferred information between the application and the main database using Restful web services with JSON data parsed back through NSJSONSerialization.

Created and maintained technical documentation

Jira utilized for requirements, issues, and bug tracking

Bugs resolved using a combination of NSLog, LLDB statements, Breakpoints, Instruments, and Crash Logs

JUNE 2015 – JULY 2016

Walgreen’s - Deerfield, IL

Junior iOS Mobile App Developer

Walgreens for iOS mobile app lets users refill prescriptions by scanning a barcode, set alerts and have live video chats. Also print photos and create personalized cards. There is also shipping, savings, coupons, rewards, and checkout at the register.

Implemented many OOP and patterns like MVC, KVO and Singleton.

Implemented new menu design and functionality for an improved user experience

Followed Apple UI guidelines throughout the iOS mobile app project.

Involved in getting requirements from the engineering team and analyzed the feasibility with the existing system design.

Implementing SiteCatalyst to track all behaviors of user.

Used Swift and Objective-C with Xcode IDE for iOS mobile app development.

Utilized Instruments, Crash Logs, LLDB statements, NSLog statements, and Breakpoints to resolve various issues and bugs brought to attention by QA team

Fixed iOS mobile memory issues by using Instruments, most notably using the Allocations and Time Profiler tools.

Added Localization to the iOS app to enable content tailored to a user’s language settings.

Implemented Apple Push Notification Service (APNS) to notify users waiting for pharmacy, for order status, refill reminders, etc.

Worked with web development team on integration of web services and search with CMS database.

Updated location finder functioning with MapKit for iOS.

Performed database operations like Insert, fetch, update and delete data.

Used JSON parser to parse fetched data from server to the iOS mobile app.

Performed review of iOS entire code base and participated in peer-to-peer code reviews.

SEPTEMBER 2014 – JUNE 2015

Greendot Mobile Banking - Pasadena, CA

Junior iOS Mobile App Developer

This is a banking app which lets users manage any Green Dot debit card or bank account. The app features a cash back function, cash deposits, bill pay and customer support chat.

Implemented the Dependency Injection of the database helper instance to the action objects.

Developed and architected application based on MVVM architectural pattern with Builder, Singleton and KVO design patterns.

Used an Agile workflow process with bi-weekly sprints, daily scrums and backlog.

Used Jira to track issues and assign tasks and worked through the backlog on Jira.

Work on bug fixing and improving application performance.

Write unit tests in XCTest and involved in iOS performance testing along with functional and regression tests.

Engaged with working on Objective-C and Cocoa framework including UIKit, Foundation, MapKit and Core Location

Thorough documentation for UAT testing for Quality Review.

Performed Error Analysis and Trace Checks to handle errors and bugs. Performed Profiling to resolve memory bugs.

Worked closely within a cross functional team of testers and developers

Worked with GDB and Xcode for debugging and verified system logic by overseeing the preparation of test data, testing and debugging during QA cycles.

Used the NSJSONSerialization class to parse the JSON and to extract the data required to customize the appearance.

Worked extensively with Objective-C and Cocoa frameworks.


Brooklyn College, NY

Bachelor of Information Systems

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