Senior Mobile App Developer - iOS & Android

We are looking for an experienced and highly skilled Mobile App Developer with 5+ years of professional experience to take ownership of developing and launching a next-generation AI-powered chatbot application for both iOS and Android, similar in concept to ChatGPT.The ideal candidate must have strong hands-on experience in cross-platform mobile application development, payment gateway integration, subscription and membership management, API integration, authentication, AI/LLM integration, and app deployment.Strong, proven experience with payment gateway integration is a MUST for this role.You will work closely with the founders, product, design, and backend teams in a fast-paced startup environment and will be expected to take ownership of features from development through production deployment and maintenance.Key Responsibilities

• Develop, maintain, and optimize a high-quality mobile application for both iOS and Android.
• Build an intuitive and responsive AI chatbot experience.
• Integrate AI/LLM APIs and implement conversational AI functionality.
• Integrate REST APIs / GraphQL APIs and work closely with backend developers.
• Design and implement secure user authentication and account management.
• Implement payment gateways and payment processing systems.
• Build and manage subscription and membership functionality.
• Implement free, premium, monthly, annual, and trial-based membership plans.
• Handle subscription upgrades, downgrades, renewals, cancellations, failed payments, refunds, and user entitlements.
• Implement in-app purchases and recurring subscriptions for iOS and Android where required.
• Manage chat history, user profiles, preferences, account settings, and other user-related functionality.
• Implement push notifications and other mobile features.
• Optimize application performance, stability, security, and scalability.
• Conduct testing, debugging, troubleshooting, and performance optimization.
• Manage complete app deployment and release processes for both Apple App Store and Google Play Store.
• Manage production releases, versioning, certificates, provisioning, signing, and store submissions.
• Monitor production applications and resolve technical issues.
• Work with analytics, crash reporting, and monitoring tools.
• Collaborate with backend developers to define API requirements and troubleshoot integration issues.
• Take ownership of features from concept * development * testing * deployment * maintenance., 2. Payment Gateway Integration Hands-on experience with payment gateway integration is mandatory.The candidate must have practical experience implementing and managing:
• Payment gateway integrations
• One-time payments
• Recurring payments
• Subscription payments
• Payment verification and transaction handling
• Payment failures and retries
• Refunds and cancellations
• Webhooks and payment status updates
• Secure payment processing
• User payment history and transaction management

Experience with platforms such as Stripe, PayPal, Razorpay, Adyen, Braintree, or similar payment providers is highly desirable.The candidate should be able to independently handle payment integration from API/SDK integration through testing and production deployment.3. Subscription & Membership ManagementStrong experience building subscription-based applications, including:

• Free and paid memberships
• Monthly and annual plans
• Free trials
• Subscription upgrades/downgrades
• Renewals
• Cancellation
• Expiration
• Payment failure handling
• User entitlements
• Feature restrictions based on membership
• Subscription status synchronization

Experience with RevenueCat, Apple StoreKit, and Google Play Billing is a strong advantage.4. AI / Chatbot IntegrationExperience integrating AI/LLM APIs is highly preferred.The candidate should understand:

• AI/LLM API integration
• Chat/completion APIs
• Streaming responses
• Conversation history
• Context management
• Token usage
• Prompt handling
• API rate limits
• Error handling and retries
• AI response optimization

Experience building an AI chatbot, ChatGPT-like application, or generative AI product will be a major advantage.5. API IntegrationStrong hands-on experience with:

• REST APIs
• GraphQL
• JSON
• API authentication
• Third-party API/SDK integration
• API error handling
• Secure API communication
• Asynchronous data handling

The developer should be comfortable working closely with backend/API teams.6. User Account & AuthenticationExperience implementing:

• Sign up / Login
• Email verification
• OTP authentication
• Google/Apple/social login
• Forgot/reset password
• User profile management
• Account settings
• Session management
• Account deletion
• Secure authentication practices

1. App DeploymentThe candidate must have experience independently managing app deployment to: * Apple App Store * Google Play Store * App Store Connect * Google Play Console * TestFlight * iOS certificates and provisioning profiles * Android signing and release builds * App review and submission processes * Production releases and version management

CI/CD experience is a plus.Technical SkillsMust Have:

• 5+ years of mobile application development
• Flutter / React Native
• iOS & Android development
• Payment gateway integration
• Subscription & membership systems
• REST APIs / GraphQL
• Authentication & account management
• Third-party API/SDK integrations
• App Store & Google Play deployment
• Debugging and performance optimization
• Git/version control

Strongly Preferred:

• AI/LLM API integration
• ChatGPT-like chatbot development
• Stripe / PayPal / Razorpay / Adyen / similar
• RevenueCat
• Apple StoreKit
• Google Play Billing
• Firebase
• Push notifications
• WebSockets / Server-Sent Events
• AWS / Azure / Google Cloud
• CI/CD
• Analytics and crash reporting

• 5+ years of professional experience in mobile application development.
• Proven experience developing and launching applications for both iOS and Android.
• Strong experience with a cross-platform framework such as Flutter or React Native.
• Experience working in a startup or fast-paced product environment is highly preferred., Startup MindsetWe are looking for someone who can build and own the product, not just write code.The ideal candidate should:
• Be comfortable working in an early-stage startup.
• Work independently with minimal supervision.
• Take complete ownership of assigned features.
• Move quickly while maintaining code quality.
• Be comfortable with evolving requirements and priorities.
• Have strong problem-solving and debugging skills.
• Proactively identify technical challenges and recommend solutions.
• Understand both the technical and product/business side of the application.
• Be comfortable working across mobile, APIs, payments, subscriptions, and AI integrations when required.

Ideal CandidateThe ideal candidate is a senior, product-minded mobile developer with 5+ years of experience who has successfully built and deployed real-world mobile applications.You should be able to independently handle:Mobile App * API Integration * AI Integration * Authentication * Payment Gateway * Subscription/Membership * Testing * App Store/Play Store Deployment * Production SupportMost importantly, hands-on payment gateway integration experience is mandatory.If you are excited about building an AI-powered product and enjoy working in a fast-moving startup environment, we would love to hear from you.

• Bereavement leave
• Company events
• Company pension
• Employee discount
• Free parking
• Gym membership
• On-site parking
• Referral programme
• Store discount
• Transport links