Senior Flutter Developer (Fintech / BLE / Cryptography)

Company Description Digital Trust Infrastructure India Limited is a deep-technology company focused on building foundational infrastructure for India's digital economy. The organization works in the critical space between how systems are designed to function and how they operate in reality, identifying structural gaps before they escalate into crises. Rather than following short-term trends, the company develops long-lasting platforms that address systemic challenges at scale. Headquartered in India and building for India first, Digital Trust Infrastructure India Limited operates with the conviction that its solutions will have impact far beyond national borders.

Location: Pune, India (or Remote)

Experience: 5+ Years

Employment Type: Full-Time

About the Role

We are seeking an elite Senior Flutter Developer to lead the mobile architecture of a highly

secure, application. You will be building a mobile platform that handles sensitive financial

data, legally binding document workflows (Aadhaar eSign), and complex cryptographic

operations.

A core component of this role involves bridging the gap between mobile software and

physical hardware. You will be responsible for integrating the Flutter application with a

custom-built BLE-to-USB hardware bridge to communicate with physical USB tokens.

If you have shipped production apps that talk to physical devices over BLE, understand how

to protect data in transit and at rest, and know when to drop down into Native Kotlin/Swift

via MethodChannels.

Key Responsibilities

• Architect & Build: Lead the end-to-end development of a high-performance, crossplatform

Flutter application for Android and iOS.

• Hardware Integration: Implement robust, low-latency Bluetooth Low Energy (BLE)

communication to transmit APDU cryptographic commands between the mobile app and

custom hardware peripherals.

• Cryptographic Workflows: Generate secure encryption document hashes, handle secure

digital signature payloads, and manage cryptographic keys securely on the device.

• Fintech Compliance: Ensure the app architecture complies with strict data minimization

and memory management protocols to meet regulatory standards.

• Native Bridging: Write and maintain custom Platform Channels (MethodChannels) to

integrate enterprise-grade RASP (Runtime Application Self-Protection) SDKs and interact

with low-level Android Keystore/iOS Secure Enclave features when Flutter abstracts too

much.

• Security Implementation: Implement SSL Pinning, root/jailbreak detection, and secure

local file encryption (AES) for cached financial documents.

• Third-Party Integration: Integrate gateway APIs and manage secure WebView/Deeplinking

redirection flows.

Required Technical Skills

• Flutter & Dart (5+ Years): Advanced proficiency in Dart, Flutter SDK, and modern state

management (Riverpod or BLoC preferred).

• Hardware / BLE: Proven commercial experience integrating flutter_blue_plus (or similar

packages) with physical hardware. You must understand GATT services, characteristics, and

hexadecimal payload parsing.

• Native Mobile (Kotlin/Swift): Strong working knowledge of native Android and iOS. You

must be comfortable writing native bridges and debugging platform-layer issues.

• Mobile Security: Hands-on experience with secure storage, encrypted databases, code

obfuscation, and biometric authentication (MFA).

• API & Networking: Expertise in handling REST APIs, WebSockets, error handling, and

offline-first data synchronization.

• CI/CD & Deployment: Experience managing App Store and Play Store releases, handling

certificates, provisioning profiles, and setting up automated pipelines (GitHub Actions,

Bitrise, or Codemagic).

Ideal Candidate Profile

• You ask why before how and understand that in financial applications, security cannot

be an afterthought.

• You understand the limitations of Flutter and know exactly when a feature requires a

native platform implementation.

• You have previous experience working in Fintech, Banking, Health-tech, or any heavily

regulated industry subject to VAPT (Vulnerability Assessment and Penetration Testing)

audits.

• You have an understanding of ISO-7816 APDU commands or smart card communication

(highly advantageous, though not strictly required).