Senior Full Stack iOS Engineer (AWS / Mobile-First)

Randstad Digital; Washington (District of Columbia); On-site; USD 103,000 - 117,000; Full time

Job summary

Randstad Digital in Washington, DC seeks a Senior Full Stack iOS Engineer to design, build, and maintain native frontline mobile apps and AWS cloud services for an enterprise transportation client. You will lead high-availability architectures and data integrity in a SAFe environment, delivering zero-downtime workflows for conductors and station staff.

Join a cross-functional team working on ticket scanning, real-time tracking, and secure backend integrations, with onsite hybrid collaboration

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 queues, and peer-to-peer or edge synchronization.
• Practical backend experience designing or integrating AWS services (API Gateway, Lambda, ECS Fargate, Cognito/Entra ID) or Spring Boot microservices.

Responsibilities

• Architect, develop, and maintain high-performance native iOS applications utilizing Swift, Objective-C, and modern concurrency models.
• Build robust, offline-first data architectures featuring local transactional queues and peer-to-peer sync.
• Deliver end-to-end frontline workflows including barcode/ticket scanning, manifest management, and check-ins with peripheral device integrations via Bluetooth.

Skills

Swift

Objective-C

Offline-first

Data synchronization

SAFe experience

Cloud integration

Education

Bachelor's degree

Tools

AWS

REST APIs

OAuth

OIDC

Job description

job summary

Randstad is seeking a 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

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.