Mobile Application Developer

Epsilon Solutions Ltd.; Toronto; On-site; CAD 90,000 - 120,000; Full time

Job summary

A leading technology firm in Toronto is seeking a Senior Mobile App Developer proficient in both iOS and Android. You will build and maintain high-quality mobile applications, ensuring security and optimal performance. Ideal candidates have over 7 years of experience with strong skills in Swift and Kotlin, and knowledge of modern architectural patterns. This position offers a long-term contract with a focus on collaboration and innovation.

Qualifications

• 7+ years of professional experience in mobile application development.
• Strong proficiency in Swift and Kotlin with architectural patterns.
• Proven track record of delivering secure mobile applications.

Responsibilities

• Support the entire mobile application lifecycle.
• Design and develop performant and secure applications.
• Collaborate with product managers and designers.

Skills

Swift

Kotlin

MVVM architecture

OOP principles

Performance profiling

Debugging

Teamwork

Communication

Tools

Git

CI/CD pipelines

Job description

Overview

Title : Senior Mobile App Developer (iOS & Android)

Term : Long Term Contract

Job Description

We are seeking an experienced Senior Mobile App Developer proficient in both iOS and Android native application development. You will be responsible for building, enhancing, and maintaining high-quality mobile applications from concept to deployment, ensuring seamless integration with backend services and third-party systems. This role requires deep expertise in both Swift (iOS) and Kotlin (Android), modern architectural patterns, and mobile security best practices.

Responsibilities

• Support the entire mobile application lifecycle (concept, design, development, testing, release, and post-release support).
• Design and develop highly performant, secure, and scalable iOS and Android applications.
• Ensure adherence to platform-specific design guidelines (Apple Human Interface Guidelines & Android Material Design).
• Collaborate closely with product managers, designers, and backend teams to deliver exceptional user experiences.
• Maintain clean, modular, and well-documented code following best practices.
• Implement robust unit testing, end-to-end testing, and continuous integration practices.
• Address application security vulnerabilities in line with OWASP Top 10 mobile security standards.
• Optimize applications for performance, offline storage, and multithreading.
• Integrate with RESTful APIs, third-party SDKs, and backend services.
• Maintain code repositories and participate in code reviews to ensure high code quality.

Qualifications & Skills

• 7+ years of professional experience in mobile application development.
• Strong proficiency in Swift (Foundation, UIKit, Core Data, RxSwift) and Kotlin with MVVM / MVP architecture.
• Extensive understanding of iOS and Android frameworks, components, and lifecycle management.
• Experience releasing applications to both the App Store and Google Play.
• Solid understanding of OOP principles, data structures, algorithms, and software design patterns.
• Familiarity with RESTful APIs, JSON, and mobile UI / UX best practices.
• Experience with code versioning tools (Git) and CI / CD pipelines.
• Strong debugging, performance profiling, and optimization skills.
• Proven track record of delivering secure mobile applications.
• Excellent communication and teamwork skills.
• A passion for learning and staying updated on emerging mobile technologies and trends.