Senior Full-Stack Mobile and Backend Developer

About the Role

• We are looking for an experienced Senior Full-Stack Mobile & Backend Developer to take technical ownership of two established mobile application platforms.
• This is a hands-on engineering role with responsibility across mobile application development, backend systems, third-party integrations, cloud infrastructure, security, deployment and ongoing maintenance.
• You will oversee the technical health, stability and continued development of both platforms, working across Flutter, PHP/Symfony, Firebase and AWS environments.
• The successful candidate will be comfortable operating independently, troubleshooting complex technical issues, managing releases and ensuring both applications remain secure, reliable and scalable.
• All client communication and project management will be handled internally by our team, allowing you to focus on technical delivery and platform ownership.

Key Responsibilities

1. Mobile Application Development

• Take ownership of iOS and Android applications.
• Maintain, troubleshoot and develop new features using Flutter and Dart.
• Manage application builds, testing and releases to the Apple App Store and Google Play Store.
• Manage release pipelines using Fastlane, TestFlight, Google Play Console and Firebase App Distribution.
• Troubleshoot mobile-specific issues, including push notifications, permissions, device compatibility and application performance.
• Work with native Swift and Kotlin code where required.

2. Backend Development & API Integrations

• Maintain and develop backend services using PHP 8.4 and Symfony.
• Manage REST API integrations, authentication and authorisation.
• Maintain PostgreSQL databases and Doctrine ORM.
• Develop and maintain background workers, scheduled tasks and automated data synchronisation.

2. Backend Development & API Integrations

• Maintain and develop backend services using PHP 8.4 and Symfony.
• Manage REST API integrations, authentication and authorisation.
• Maintain PostgreSQL databases and Doctrine ORM.
• Develop and maintain background workers, scheduled tasks and automated data synchronisation.
• Manage Firebase Cloud Functions using Node.js/TypeScript.
• Maintain integrations with third-party CRM platforms, including APIs and webhooks.
• Ensure accurate and reliable synchronisation of membership, booking, class, contract and payment data.

3. Cloud Infrastructure & DevOps

• Maintain and manage AWS infrastructure, including EC2, Aurora, S3, EFS, ECR and Secrets Manager.
• Manage load balancing, autoscaling and application hosting environments.
• Maintain Docker-based environments and nginx configuration.
• Manage CI/CD pipelines using GitHub Actions.
• Ensure infrastructure is secure, reliable, scalable and appropriately maintained.
• Manage environment configuration, access permissions, credentials and secrets.

4. Firebase & Application Services

• Maintain Firebase services, including Authentication, Firestore, Cloud Functions, Remote Config and Cloud Messaging.
• Monitor application stability through Crashlytics and Firebase Analytics.
• Maintain push notification functionality and related integrations.
• Troubleshoot issues across Firebase services and connected applications.

5. Monitoring, Security & Maintenance

• Monitor application and infrastructure performance using Grafana, Loki and Crashlytics.
• Investigate and resolve production issues.
• Maintain appropriate backup, recovery and disaster recovery procedures.
• Implement security best practices across applications, infrastructure, databases and administrative tools.
• Proactively identify technical risks, performance bottlenecks and opportunities for improvement.

• Maintain technical documentation and ensure systems are maintainable over the long term.

   

6. Third-Party Integrations & Content Platforms

• Maintain integrations with third-party CRM platforms, which act as the primary data source for application functionality.
• Support integrations with Firebase, InBody, Google Translate, Pexels and external website content feeds.
• Maintain WordPress-connected content feeds and integrations where required.
• Ensure third-party services communicate reliably with mobile applications and backend systems.

Technical Environment

The developer will be responsible for maintaining two distinct technical environments.

Mobile Development

• Flutter / Dart (iOS and Android)
• Native Swift and Kotlin
• Bloc / Cubit
• Dio

• Hive

   

Backend Development

• PHP 8.4
• Symfony 6.4
• REST APIs and OAuth
• PostgreSQL 17
• AWS Aurora
• Doctrine ORM
• Symfony EasyAdmin

• Node.js / TypeScript

   

Cloud Infrastructure & DevOps

• AWS EC2, Load Balancing and Autoscaling
• AWS Aurora, S3, EFS, ECR and Secrets Manager
• Docker and nginx
• GitHub Actions

• Fastlane

   

Firebase & Application Services

• Cloud Functions
• Firebase Authentication
• Firestore
• Remote Config
• Firebase Cloud Messaging

• Crashlytics and Analytics

   

Monitoring & Integrations

• Grafana
• Loki
• Slack alerts
• Third-party CRM APIs and webhooks
• WordPress integrations

• External content and data feeds

   

Essential Requirements

We are looking for someone with strong hands-on experience across the following areas:

• CRM Integration Experience: Previous experience integrating with PerfectGym CRM is a key requirement, given its role as the primary data source for both platforms. Experience with its APIs, webhooks and data synchronisation is particularly important.
• Flutter & Dart: Strong commercial experience developing and maintaining cross-platform iOS and Android applications.
• Mobile App Releases: Proven experience managing application builds, signing, testing and publishing releases through App Store Connect and Google Play Console, including Fastlane and TestFlight.
• PHP & Symfony: Strong backend development experience, ideally with Symfony 6 or later.
• PostgreSQL & Doctrine: Experience managing relational databases, queries, ORM and database performance.
• Firebase: Experience with Cloud Functions (Node.js/TypeScript), Authentication, Firestore, Cloud Messaging, Remote Config and Crashlytics.
• AWS & DevOps: Practical experience managing AWS infrastructure, including EC2, Aurora, S3, ECR, Secrets Manager, load balancing and autoscaling.
• CI/CD: Experience building and maintaining automated deployment pipelines using GitHub Actions.
• API Integrations: Strong experience working with REST APIs, OAuth, webhooks and scheduled data synchronisation.
• Security: Understanding of infrastructure security, access management, secrets handling, backups and recovery.

Desirable Experience

• Native iOS development using Swift.
• Native Android development using Kotlin.
• Experience troubleshooting mobile permissions, push notifications and native build configurations.
• Monitoring and logging experience using Grafana, Loki and Firebase Crashlytics.
• WordPress development and third-party content integrations.
• Experience independently maintaining and supporting live production applications.

What Makes This Role Different?

• This is not a role focused solely on mobile application development or backend engineering. You will have responsibility for the complete technical ecosystem behind two live mobile platforms.
• You will become the primary technical owner of both applications, with the opportunity to influence their ongoing development, architecture, performance and reliability.
• You will work closely with our internal delivery team, while client communication, project coordination and account management remain within our organisation.