Sr. iOS Developer

Sr iOS Developer Job Type: Sr iOS Developer Contract Duration: 6 months, possible extension Pay Rate/Salary: $70 - $100/hr Location: 1 day onsite in Downtown Toronto Your New Company Our client in retail industry is building secure, high-performance authentication experiences or designing SDKs that power seamless login across millions of devices. Your New Role As part of the Development team focused on our Login SDK platform, you’ll play a key role in architecting and delivering robust authentication modules used by multiple apps across millions of devices. You will be exposed to every aspect of the software development cycle and encouraged to express your opinions and challenge assumptions. Guidance from Mobile Tech Leads will ensure code quality and best practices. This is a hands-on role where you’ll build reusable mobile SDKs integrated into customer-facing apps with millions of downloads as well as colleague-facing tools. You’ll interface with RESTful APIs while ensuring your code meets strict requirements for security, performance, reliability, observability—and seamless integration by other teams. What You Need to Do Design, build, document, and maintain native iOS Login SDK components. Architect clean interfaces and frameworks for easy integration by client app teams. Implement instrumentation hooks for logging, metrics, and tracing to support observability. Ensure optimal performance (startup time, memory footprint, network efficiency) through profiling and tuning. Participate in code reviews and architecture discussions with a focus on modularity, scalability, and testability. Collaborate closely with cross-functional teams—including product managers, security engineers, QA specialists, Android/mobile developers—to define requirements and deliver end-to-end solutions. Take full ownership: drive features from design through release; proactively monitor crash and performance dashboards; address issues rapidly; champion improvements based on feedback from integrators. Write comprehensive unit, integration, and UI tests; maintain high standards for code quality and reliability. Mentor junior developers on best practices for reusable framework and SDK design. What You'll Need to Succeed: Proven experience designing and building mobile SDKs or frameworks consumed by external and internal clients. Strong understanding of API design principles, including versioning, backward compatibility, and SDK lifecycle management. Deep knowledge of Swift and iOS development best practices; familiarity with Objective-C is an asset. Experience with modern iOS architecture patterns such as MVVM, Clean Architecture, and modular application design. Experience implementing analytics, logging, and monitoring solutions using tools such as Firebase Crashlytics, Firebase Performance Monitoring, OpenTelemetry, or similar platforms. Familiarity with monitoring production issues through observability solutions such as Datadog, Splunk, Grafana, or equivalent. Demonstrated ability to profile and troubleshoot memory leaks, threading/concurrency issues, and network bottlenecks using Xcode Instruments and related tooling. Experience writing clear technical documentation, integration guides, and sample applications to support SDK adoption. Strong understanding of secure coding practices, particularly around authentication flows, token management, secure storage, encryption, and Keychain services. Ability to work effectively across multiple teams: Gather requirements collaboratively Communicate technical decisions clearly to stakeholders Resolve integration challenges efficiently Share knowledge openly within the organization Familiarity with CI/CD pipelines (Fastlane, GitHub Actions, Jenkins, Bitrise, Azure DevOps), automated testing frameworks (XCTest, XCUITest), dependency management tools (Swift Package Manager, CocoaPods), networking libraries (URLSession, Alamofire), local persistence solutions (Core Data, Realm), and SwiftUI. What You'll Get in Return You will have the opportunity to work with a talented team of professionals in a dynamic and supportive environment. Competitive compensation, professional development opportunities, and the chance to make a significant impact on clients' success. What You Need to Do Now: If you're interested in this role, click 'apply now' to forward an up-to-date copy of your CV, or call us now. If this job isn't quite right for you, but you are looking for a new position, please contact us for a confidential discussion on your career. This posting is for an existing vacancy with the organization. AI may be used to screen, assess or select applicants for the position.

You will design, build, document, and maintain native iOS Login SDK components while ensuring optimal performance and security. You will collaborate with cross-functional teams to define requirements and deliver end-to-end solutions.

Proven experience in designing and building mobile SDKs is essential, along with a strong understanding of API design principles. Familiarity with modern iOS architecture patterns and secure coding practices is also required.

• Data analysisPreferred

Identified from the job description. Confirm important requirements above.

• iOS Development
• Swift
• Objective-C
• SDK Design
• API Design
• MVVM
• Clean Architecture
• Analytics
• Logging
• Monitoring
• CI/CD
• Automated Testing
• Networking
• Secure Coding
• Documentation
• Performance Tuning

• Technology
• Software
• Retail

Minimum experience

5+ years

Apply by

Aug 13, 2026

Posting language

English

Working hours

40 hours per week

Office presence

1 days per week

Seniority

Mid-Senior level

Application method

Direct apply is available