iOS Mobile Application Developer - Swift & SwiftUI

Seneca Resources; New York (NY); Hybrid; USD 107,000 - 121,000; Full time

Job summary

Seneca Resources is seeking an iOS Mobile Application Developer specializing in Swift and SwiftUI. The role requires hands-on coding, API integration, and a proactive approach to debugging and performance tuning.

You will work in a hybrid environment with 3 days onsite in New York, NY, and 2 days remote, contributing to a large enterprise mobile solution. The ideal candidate will have 18+ months of iOS experience, familiarity with Core Data/SwiftData, and strong knowledge of design patterns,

Qualifications

• Bachelor's degree in Computer Science or related field.
• 18+ months of professional iOS development experience.
• Hands-on experience with Swift, SwiftUI and Objective-C.
• Experience with Xcode and Instruments.
• Experience with MVC, MVVM, MV, Singleton patterns and GCD.
• Experience consuming REST APIs and JSON; GitHub and CI/CD.
• Experience with Core Data or SwiftData and persistent stores.
• Experience with testing, code reviews, and documentation.

Responsibilities

• Design, develop, enhance, test, and maintain native iOS apps.
• Develop using Swift, SwiftUI, and Objective-C; use Xcode/Instruments.
• Own development tasks from requirements to implementation.
• Collaborate with stakeholders; mentor teammates as needed.
• Integrate APIs and data services; troubleshoot production issues.
• Contribute to architectural decisions and design discussions.
• Write technical docs and participate in CI/CD releases.

Skills

Swift

SwiftUI

Objective-C

Xcode

Core Data/SwiftData

APIs

Concurrency

Design patterns

Testing

UI/UX development

Education

Bachelor's degree in Computer Science or related

Tools

GitHub

Firebase

Crashlytics

Sentry.io

Cursor

Swift Package Manager

Carthage

CI/CD

Job description

Job Title: iOS Mobile Application Developer - Swift & SwiftUI

Location: Hybrid; New York, NY (3 days onsite, 2 days remote)

Hours: 37.5/week (required 4 weeks unpaid vacation)

Duration: 12+ Month Contract, likely extension

Pay range: $78-$88.25/hr (W2), depending on experience

Interview: Could be onsite in New York, NY or remote via Teams (up to hiring manager). Likely 1-2 rounds of interviews

Our Government client in New York, NY is seeking an iOS Mobile Application Developer – Swift & SwiftUI to design, develop, enhance, troubleshoot, and support production mobile applications within a large enterprise environment.

This is a hands‑on iOS development position requiring professional experience with Swift, SwiftUI, Objective‑C, Xcode, Core Data/SwiftData, APIs, concurrency, design patterns, testing, and mobile UI/UX development. The developer will take ownership of assigned application development initiatives, work with business stakeholders to validate technical requirements, integrate APIs and data services, troubleshoot production issues, and create supporting technical documentation.

The ideal candidate is capable of working independently while collaborating effectively within a development team. In addition to hands‑on coding, this individual should be comfortable assisting other developers with technical challenges, participating in code reviews, and providing technical guidance and mentorship when needed.

Key Responsibilities

iOS Application Development

• Design, develop, enhance, test, and maintain native iOS applications.
• Develop application functionality using Swift, SwiftUI, and Objective‑C.
• Use Xcode and Instruments for application development, debugging, profiling, and optimization.
• Take ownership of assigned application design and development tasks from requirements through implementation.
• Develop reliable, maintainable, and reusable application components.
• Apply appropriate software design patterns and iOS development best practices.
• Support existing production applications while developing new functionality.

Application Architecture & Concurrency

• Apply mobile application design patterns including MVC, MVVM, MV, and Singleton.
• Develop asynchronous and concurrent application functionality using Grand Central Dispatch (GCD), multithreading, concurrency, and operation queues.
• Design applications for responsiveness, maintainability, and performance.
• Identify and resolve threading, performance, and application lifecycle issues.
• Participate in technical design decisions and architecture discussions.

Data, APIs & Integrations

• Develop and maintain persistent application data using Core Data, SwiftData, and other persistent stores.
• Integrate mobile applications with web services and external APIs.
• Handle and parse JSON data received from APIs and web services.
• Manage application data and ensure reliable interaction between mobile applications and backend systems.
• Troubleshoot API, network, data, and integration‑related issues.
• Support integration of third‑party libraries, SDKs, and enterprise services.

UI/UX Development

• Translate UI/UX designs and wireframes into functional iOS application experiences.
• Develop intuitive, responsive, and maintainable user interfaces using SwiftUI and related iOS technologies.
• Collaborate with stakeholders to validate application requirements and user experience expectations.
• Identify opportunities to improve application usability and performance.
• Ensure developed functionality aligns with approved designs and requirements.

Testing, Debugging & Production Support

• Perform application debugging and resolve reported defects in a timely manner.
• Develop and execute unit tests for application functionality.
• Participate in peer code reviews and maintain established coding standards.
• Use application monitoring and diagnostics tools such as Firebase, Crashlytics, and Sentry.io.
• Analyze application crashes, errors, and performance issues and implement durable resolutions.
• Support CI/CD processes and reliable application releases.
• Troubleshoot complex application and integration issues using strong analytical and debugging skills.

Development Tools & Source Control

• Use GitHub for source control, collaboration, and code management.
• Work with dependency management technologies such as Swift Package Manager, Carthage, or comparable tools.
• Utilize Firebase and Crashlytics for application services and monitoring.
• Work with modern AI‑assisted development tools such as Cursor or comparable solutions where appropriate.
• Participate in established CI/CD and software delivery processes.

Technical Leadership & Documentation

• Create and maintain clear technical documentation for application functionality, integrations, and development processes.
• Assist team members with coding and technical issues.
• Provide technical guidance and mentoring to other team members as appropriate.
• Vet technical requirements with business stakeholders and clarify implementation requirements.
• Communicate technical issues and recommendations effectively to technical and non‑technical audiences.
• Work independently, take ownership of deliverables, and contribute effectively as a collaborative team member.

Required Qualifications

• Bachelor's degree from an accredited college or university in Computer Science or a related field.
• Minimum 18 months of professional iOS development experience, with a strong focus on mobile application development.
• Hands‑on experience with Swift, SwiftUI, and Objective‑C.
• Experience developing and debugging applications using Xcode and Instruments.
• Experience with MVC, MVVM, MV, Singleton, and other software design patterns.
• Experience with Grand Central Dispatch (GCD), concurrency, multithreading, and operation queues.
• Experience with Core Data, SwiftData, and/or persistent data stores.
• Experience consuming web services/APIs and handling and parsing JSON.
• Experience with GitHub, Firebase, Crashlytics, and CI/CD.
• Experience with application monitoring/error‑management tooling such as Sentry.io.
• Experience with Swift Package Manager, Carthage, or similar dependency management tools.
• Experience translating UI/UX designs and wireframes into mobile application functionality.
• Experience developing technical documentation.
• Experience with unit testing and code reviews.
• Strong analytical, debugging, and problem‑solving abilities.
• Strong written and verbal communication skills.
• Ability to independently own development assignments while collaborating effectively within a team.
• Ability to provide technical guidance and mentorship to other developers when needed.

Critical Skills

Skill Area Requirement Priority iOS Application Development 18+ months Critical Swift / SwiftUI Hands‑on professional experience Critical Objective‑C 1–2+ years targeted Critical Xcode / Instruments Hands‑on experience Critical Core Data / SwiftData Hands‑on experience Critical GCD / Concurrency / Multithreading Hands‑on experience Critical REST APIs / JSON Hands‑on experience Critical MVC / MVVM & Design Patterns Hands‑on experience Highly Relevant GitHub / CI/CD Hands‑on experience Highly Relevant Firebase / Crashlytics / Sentry.io Hands‑on experience Highly Relevant

Preferred Qualifications

• Experience developing Android applications with Kotlin.
• Experience integrating payment gateways into mobile applications.
• Experience with mobile ticketing solutions.
• Experience with ticket validation or QR/barcode scanning SDKs.
• Experience with mobile app‑to‑app integrations.
• Experience with CoreBluetooth/BLE.
• Experience integrating external hardware and accessories using MFi / External Accessory Framework.
• Experience integrating barcode scanners, sleds, receipt printers, or comparable peripheral devices.
• Understanding of network protocols.
• Experience with cloud technologies.
• Exposure to additional development technologies such as C++, PHP, .NET, C#, JavaScript, and Oracle SQL.

Technologies

• Swift
• SwiftUI
• Objective‑C
• Xcode
• Instruments
• Core Data
• SwiftData
• Grand Central Dispatch (GCD)
• REST APIs / Web Services
• JSON
• GitHub
• Firebase
• Crashlytics
• Sentry.io
• Cursor
• Swift Package Manager
• Carthage
• CI/CD
• Kotlin
• CoreBluetooth / BLE
• MFi / External Accessory Framework