SIM Over-The-Air (OTA) Developer

Flint UK Technology Services; City of Westminster; Hybrid; GBP 45,000 - 70,000; Full time

Job summary

A technology services provider is seeking a SIM Over-The-Air (OTA) Developer to design and maintain OTA solutions for SIM/eSIM platforms. This role requires strong experience in SIM OTA technologies and programming skills in Java, C/C++, or Python. The developer will work on secure remote provisioning, ensuring compliance with telecom standards, and collaborating with various teams. This position offers flexibility with remote, hybrid, or onsite work options.

Qualifications

• Experience with OTA protocols (SMS‑PP, CAT‑TP, SCP80/SCP81) is required.
• Familiarity with SMPP, SMSC integration, and mobile network environments is important.
• Domain knowledge in mobile telecom ecosystems and SIM life‑cycle management is essential.

Responsibilities

• Design, develop, and maintain SIM OTA applications.
• Implement secure OTA messaging for SIM/eSIM provisioning.
• Collaborate with network, security, and platform teams.

Skills

Strong experience in SIM OTA technologies

Hands‑on experience with SIM Toolkit (STK)/Java Card

Experience with eSIM/RSP architecture

Knowledge of cryptography

Programming experience in Java, C/C++, or Python

Job description

SIM Over-The-Air (OTA) Developer

Contract Type: 12-Month Contract (Extendable based on project needs)

Location: Remote/Hybrid/Onsite (as applicable)

Start Date: TBD

Role Overview

We are seeking experienced SIM Over-The-Air (OTA) Developers to support the design, development, deployment, and maintenance of OTA solutions for SIM/eSIM platforms. The role focuses on secure remote provisioning, life cycle management, and updates of SIM profiles across large-scale mobile networks.

Key Responsibilities

• Design, develop, and maintain SIM OTA applications in compliance with 3GPP and GSMA standards
• Implement secure OTA messaging for SIM/eSIM provisioning, updates, and life cycle management
• Integrate OTA platforms with HSMs, SMSCs, SMPP gateways, and mobile core systems
• Develop and manage SIM Toolkit (STK)/CAT-TP based applications
• Support eSIM (Remote SIM Provisioning - RSP) workflows including profile download, enablement, and deletion
• Perform OTA testing, validation, and troubleshooting across multiple devices and operators
• Ensure compliance with security, encryption, and key management standards
• Collaborate with network, security, and platform teams to deliver end-to-end OTA solutions
• Provide documentation, deployment support, and knowledge transfer

Required Skills & Experience

Technical Skills

• Strong experience in SIM OTA technologies
• Hands‑on experience with SIM Toolkit (STK)/Java Card, OTA protocols (SMS‑PP, CAT‑TP, SCP80/SCP81), 3GPP, ETSI, and GSMA specifications
• Experience with eSIM/RSP architecture
• Knowledge of cryptography, key management, and secure messaging
• Familiarity with SMPP, SMSC integration, and mobile network environments
• Programming experience in Java, C/C++, or Python

Domain Knowledge

• Mobile telecom ecosystems and SIM life‑cycle management
• SIM personalization, provisioning, and OTA security domains

Preferred/Nice-to-Have

• Experience with OTA platforms (eg, Thales, G+D, IDEMIA, or equivalent)
• Exposure to IoT SIM/eSIM deployments
• Experience working with HSMs and secure key injection
• Familiarity with CI/CD pipelines in telecom environments
• Prior experience in large-scale operator or MVNO environments