iOS Developer (Frontend SDK)

Ethereum Technologies LLC; San Leandro (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Ethereum Technologies LLC is seeking an experienced iOS Developer to design and build frontend SDKs powering secure, high-performance mobile applications. You will create reusable Swift/Objective-C components that drive digital wallets, authentication, and payments while collaborating with product, architecture, and backend teams.

You will optimize startup times, memory usage, and implement PCI-DSS aligned coding practices, providing tests and developer docs for broad external integration.

Qualifications

• 10+ years of iOS development experience.
• Expert-level proficiency in Swift; working knowledge of Objective-C.
• Strong experience designing or maintaining mobile SDKs / frameworks.
• Hands-on experience with Xcode, Instruments, XCTest.
• Knowledge of REST APIs, JSON parsing, and mobile security.
• Experience delivering SDKs used by large developer communities.

Responsibilities

• Design, develop, and maintain iOS Frontend SDKs using Swift and/or Objective-C.
• Build reusable client-side libraries, UI components, and frameworks for mobile payment solutions.
• Integrate payment and authentication APIs with secure transaction services.
• Optimize SDK performance, startup time, and memory usage.
• Create automated tests, documentation, and sample apps for developers.
• Collaborate with product, architecture, and backend teams; mentor juniors.

Skills

iOS development

Swift

Objective-C knowledge

SDK/framework design

Security best practices

Memory optimization

Multithreading (GCD/OperationQueue)

Code reviews & Agile

Education

Bachelor's or Master’s degree in CS/Engineering

Tools

Xcode

Instruments

XCTest

Swift Package Manager

CocoaPods

Carthage

Job description

The client is seeking a highly skilled iOS Developer with strong expertise in building Frontend SDKs for high-scale, secure, and high-performance mobile applications. In this role, you will design, develop, and optimize iOS SDK components that power client’s next-generation payment experiences, digital wallets, authentication frameworks, and secure transaction flows.

You will collaborate closely with product managers, architects, backend platform teams, and client’s global developer ecosystem to build best-in-class mobile SDKs used by merchants, partners, and financial institutions worldwide.

Key Responsibilities:

• SDK Design & Development:
• Design, develop, and maintain iOS Frontend SDKs using Swift and/or Objective-C.
• Build reusable client-side libraries, UI components, and frameworks for client’s mobile payment solutions.
• Ensure SDKs are lightweight, modular, scalable, and seamless for third-party integration.
• Integration & APIs
• Integrate payment APIs, authentication APIs, and secure transaction services.
• Work with RESTful APIs, JSON data structures, and backend engineering teams to ensure smooth communication between systems.
• Provide technical support for internal and external partners integrating iOS SDK.
• Performance & Security:
• Optimize mobile SDK performance, startup time, and memory usage.
• Implement highly secure coding practices aligned with PCI-DSS and client’s internal compliance.
• Work with encryption modules, secure storage, tokenization, and device authentication.
• Testing & Documentation:
• Develop automated unit tests, UI tests, and integration tests for SDK reliability.
• Create comprehensive developer documentation, integration guides, and sample apps.
• Support continuous integration/continuous deployment (CI/CD) pipelines for SDK releases.
• Cross-Functional Collaboration:
• Partner with product, design, and architecture teams to define mobile-first solutions.
• Participate in code reviews, sprint planning, and Agile ceremonies.
• Provide mentorship to junior developers and contribute to engineering best practices.

Required Skills & Qualifications:

Technical Skills:

• 10+ years of iOS development experience.
• Expert-level proficiency in Swift; working knowledge of Objective-C.
• Strong experience designing or maintaining mobile SDKs / frameworks.
• Hands-on experience with:
• Xcode, Instruments, XCTest
• Swift Package Manager / CocoaPods / Carthage
• REST APIs & JSON parsing
• Mobile security mechanisms (Keychain, certificates, OAuth, tokenization)
• Memory management, performance tuning, multithreading (GCD/OperationQueue)

Domain Skills:

• Exposure to payment systems, digital wallets, or fintech applications is highly preferred.
• Experience working with Visa, Mastercard, EMV, token services, or other payment ecosystems is a strong plus.

Soft Skills:

• Strong communication, documentation, and problem-solving abilities.
• Ability to collaborate in a fast-paced, cross-functional environment.
• Detail-oriented with a focus on secure and scalable engineering solutions.

Preferred Qualifications:

• Experience building SDKs adopted by large-scale developer communities.
• Knowledge of cryptographic libraries, secure enclave, or authentication frameworks.
• Familiarity with Agile, CI/CD, Git, Jenkins, or GitHub Actions.
• Bachelor’s or Master’s degree in Computer Science, Engineering, or related field.

ETHEREUM TECHNOLOGIES LLC is an equal opportunity employer inclusive of female, minority, disability and veterans, (M/F/D/V). Hiring, promotion, transfer, compensation, benefits, discipline, termination and all other employment decisions are made without regard to race, color, religion, sex, sexual orientation, gender identity, age, disability, national origin, citizenship/immigration status, veteran status or any other protected status. ETHEREUM TECHNOLOGIES LLC will not make any posting or employment decision that does not comply with applicable laws relating to labor and employment, equal opportunity, employment eligibility requirements or related matters. Nor will ETHEREUM TECHNOLOGIES LLC require in a posting or otherwise U.S. citizenship or lawful permanent residency in the U.S. as a condition of employment except as necessary to comply with law, regulation, executive order, or federal, state, or local government contract