Senior Flutter / Mobile Application Engineer

About Xenter

Xenter pioneers advancements in medical technology, creating diagnostic tools that enable earlier detection of conditions and procedural innovations aimed at delivering more cost-efficient treatments to a wide patient base. Their solutions enhance clinicians' capabilities by providing real-time data to support precision and consistency in decision-making. Emphasizing data integrity, validation, and continual enhancements, Xenter is developing a connected clinical intelligence platform that systematically collects and organizes procedural and care data. This platform is intended to broaden access to sophisticated diagnostics while overcoming care delivery challenges, ultimately improving efficiency and lowering overall healthcare expenses, benefiting providers, health systems, and patients alike.

Joining Xenter means becoming part of a fast-moving entrepreneurial environment where innovation swiftly materializes, and every team member plays a role in shaping transformative healthcare technologies. Collaboration with leading industry experts and involvement in directing company growth offers a unique opportunity to advance breakthrough products from concept through commercialization.

Role Overview

The Senior Flutter/Mobile App Engineer will architect and deliver cross-platform mobile applications that serve both patients and healthcare providers within the Xenter ecosystem. This role is responsible for leading mobile app development strategies, ensuring integration with connected medical devices, and establishing technical standards as the engineering team expands.

Key Responsibilities

• Develop cross-platform mobile applications for iOS and Android using Flutter and Dart, supporting workflows for both patients and providers.
• Responsible for the overall mobile app architecture, including state management and maintaining high code quality standards.
• Design Cubit/BLoC-based UI screens incorporating appropriate state and repository layers.
• Enhance the existing Dio-based networking infrastructure with components such as interceptors, retry mechanisms, timeout controls, error handling normalization, and certificate pinning for security.
• Integrate clinical data accessed via FHIR R4 standards through native platform channels.
• Implement features interacting with a large language model chat backend using role-specific prompts and secure, PHI-compliant streaming.
• Maintain rigorous testing across all layers including widgets, cubit, repositories, and security regressions.
• Collaborate with the device connectivity team to integrate Bluetooth Low Energy (BLE) devices into mobile applications.
• Develop robust offline-first capabilities suitable for clinical environments and field operations.
• Manage application releases including App Store and Google Play processes, version control, and compliance adherence.
• Provide mentorship to other mobile developers and help define engineering standards.
• Coordinate with design, product management, and clinical teams to translate clinical and patient service workflows into mobile application features.

Required Qualifications

• Minimum of 5 years experience in mobile app development, with at least 3 years focused on Flutter and Dart.
• Comprehensive understanding of mobile app architectural patterns such as BLoC, Provider, or Riverpod.
• Expertise with widget lifecycle management, build performance optimization, and platform channel communication.
• Proficient in RESTful API fundamentals including HTTP verbs, status codes, idempotency, pagination, and error handling.
• Hands-on experience with Dio networking or similar libraries (http, chopper, retrofit) covering interceptors, transformers, and cancellation tokens.
• Knowledge of OAuth 2.0 flows (authorization code with PKCE), JWT handling including parsing and refresh tokens, and session lifecycle management.
• Understanding of certificate and SPKI pinning alongside TLS trust chain concepts.
• Experience implementing layered caching setups: memory, disk, and HTTP caching.
• Ability to select appropriate local data storage tools (flutter_secure_storage, shared_preferences, hive, isar, sqflite, drift) based on data sensitivity and querying needs.
• Proficiency in cache invalidation techniques such as TTL, ETag, and event-driven approaches.
• Familiarity with iOS app provisioning, entitlements (HealthKit, Keychain sharing), and experience with App Store submissions.
• Track record of shipping production applications on both Apple App Store and Google Play Store.
• Insight into native iOS/Android platform specifics and platform channel integration.
• Demonstrated independence making technical decisions within small teams.

Preferred Qualifications

• Experience integrating mobile applications with Bluetooth Low Energy (BLE) medical or IoT devices.
• Background in regulated technical environments such as healthcare or medical devices.
• Familiarity with Continuous Integration/Continuous Deployment (CI/CD) tools for mobile apps like Fastlane or Codemagic.
• Knowledge of accessibility standards pertinent to clinical or patient applications.
• Experience working with healthcare regulations such as HIPAA or in other regulated domains like finance or government.
• Exposure to HealthKit, Google Fit, or FHIR R4 implementations.
• Understanding OAuth integrations with SMART-on-FHIR or electronic health records such as Epic and Cerner.
• Experience developing LLM/chat features with secure streaming, prompt controls, and PHI redaction.

Physical Requirements and Environment

This role is based in a professional office setup requiring routine use of standard office equipment such as computers and monitors. It predominantly involves sedentary work with extended computer use, although some mobility within the office is necessary.

Additional Notes

The outlined responsibilities and duties are subject to change based on company needs and may evolve over time without prior notification.