Senior Full Stack iOS Engineer

Randstad

randstad

Senior Full Stack iOS Engineer to design, build, and maintain mission-critical, native frontline mobile applications and the supporting AWS cloud services for our enterprise transportation client in Washington, DC. In this role, you will lead the architecture of high-availability, offline-first passenger and employee operations, enabling reliable ticket scanning, real-time manifest tracking, peer-to-peer data synchronization, and secure backend integrations used daily by onboard conductors and station personnel. Working within an established Scaled Agile Framework (SAFe) environment, you will drive self-organized iteration planning, collaborate on resilient cloud/mobile contracts, and directly deliver seamless digital workflows where zero-downtime and data integrity are non-negotiable.

location: Washington, Washington, D.C. job type: Contract salary: $75 - 85 per hour work hours: 9am to 5pm education: Bachelors

responsibilities

• Architect, develop, and maintain high-performance native iOS applications utilizing Swift, applicable Objective-C, and modern concurrency models.

• Build robust, offline-first data architectures featuring local transactional queues, conflict resolution, reconnection/replay logic, and peer-to-peer sync mechanisms (e.g., Ditto, Infinite PeerConnect).

• Deliver end-to-end frontline workflows, including barcode/ticket scanning, passenger manifest management, check-in/lift states, and peripheral device integrations via Bluetooth.

• Design and integrate mobile clients with Backend-for-Frontend (BFF) REST APIs on AWS, leveraging OAuth/OIDC authentication, secure device storage, and request correlation.

• Implement reusable, configuration-driven UI components, feature flags, dynamic forms, and role-based workflows across supported iPhone and iPad devices.

• Instrument applications with Dynatrace mobile RUM, crash symbolization, privacy safeguards, and real-time performance telemetry.

• Partner with backend and platform teams on contract testing, API idempotency, and unified mobile-to-cloud data schemas.

• Champion Agile self-management within a SAFe structure-actively participating in capacity planning, iteration commitments, and onsite Program Increment (PI) planning events in Washington, DC.

qualifications

• Proven track record building enterprise native iOS applications in production using Swift and Objective-C.

• Hands-on experience architecting offline-first mobile systems, Core Data persistence, local queueing, and peer-to-peer or edge synchronization frameworks.

• Practical backend experience designing or integrating AWS services, including API Gateway, Lambda, ECS Fargate, and Cognito/Entra ID (or Spring Boot microservices).

• Direct experience integrating external hardware peripherals (barcode scanners, sleds, or Bluetooth/BLE devices).

• Demonstrated knowledge of mobile performance optimization, thread safety, crash resilience, VoiceOver accessibility, and mobile monitoring tools like Dynatrace RUM.

• Familiarity with high-availability operational environments such as transportation, ticketing, reservations, or point-of-sale systems.

• Working knowledge of or formal training in SAFe (Scaled Agile Framework), with the ability to lead sprint commitments and capacity planning autonomously.

• Must be based within commuting distance of Washington, DC, available to attend key milestone ceremonies (such as PI Planning) onsite, and comfortable maintaining a camera-on collaborative presence during hybrid team sessions.

skills

• Fargate,AWS cloud services,AWS,AWS services,API Gateway,API,backend,Bluetooth,Core Data,data integrity,data synchronization,Dynatrace,Frontend,UI components,microservices,mobile applications,OAuth,Objective-C,OIDC,peer-to-peer,performance optimization,REST APIs,Scaled Agile Framework,Spring Boot,integrating,digital workflows,ability to lead,resilient,resilience,self-management,high-performance,architecture,barcode,barcode scanners,capacity planning,conflict resolution,VoiceOver,point-of-sale systems,self-organized,telemetry,testing,workflows

• Equal Opportunity Employer: Race, Color, Religion, Sex, Sexual Orientation, Gender Identity, National Origin, Age, Genetic Information, Disability, Protected Veteran Status, or any other legally protected group status.

• At Randstad Digital, we welcome people of all abilities and want to ensure that our hiring and interview process meets the needs of all applicants. If you require a reasonable accommodation to make your application or interview experience a great one, please contact [email protected].

• Pay offered to a successful candidate will be based on several factors including the candidate's education, work experience, work location, specific job duties, certifications, etc. In addition, Randstad Digital offers a comprehensive benefits package, including: medical, prescription, dental, vision, AD&D, and life insurance offerings, short-term disability, and a 401K plan (all benefits are based on eligibility).

• This posting is open for thirty (30) days.