SIM Engineer

Our mission is to develop innovative building blocks that make high-quality connectivity more accessible and affordable to people and things in our planet. Simply put, we're solving world's persistent connectivity problem.

Bloxtel's engineers develop the cutting-edge technologies that will change the way the next billion of devices will connected to mobile networks. Our products need to handle connectivity transactions at massive scale, and extend well beyond blockchain and telecom.

We're looking for experienced SIM Engineers who bring fresh ideas from all areas of SIM card technology. As a SIM Engineer, you will work on our patented dSIM technology which consists of a custom eSIM profile including a suite of intertwined Java Card applets. You will start with a specific project critical to Bloxtel’s needs with opportunities to switch teams and projects as you and our fast-paced business grow and evolve. We need our engineers to be versatile, display leadership qualities and be enthusiastic to take on new problems across the full-stack as we continue to push technology forward. With your technical expertise you will manage project priorities, deadlines, and deliverables. You will design, develop, test, deploy, maintain, and enhance our dSIM software stack.

Key Responsibilities & Duties:

• dSIM/eSIM Development: Design and develop custom eSIM profiles and dSIM technology using JavaCard programming.
• Applet Programming: Create and maintain intertwined Java Card applets for secure SIM functionality.
• Security Implementation: Implement public key cryptography and secure authentication protocols for SIM cards.
• Integration & Testing: Integrate SIM card APIs with decentralized backend systems and conduct thorough testing of applet functionality.
• AI-Augmented Development: Leverage AI coding assistants (Claude, Codex, Gemini) in IDEs, CLI, and CI/CD pipelines to significantly improve productivity.

Minimum Qualifications:

• Bachelor’s degree or equivalent practical experience.
• 4 years of experience with software development in JavaCard programming languages. C is a plus.
• 4 years of experience with developing large-scale infrastructure, distributed systems or networks.
• 4 years of experience with SIM card API integration.
• Strong Knowledge of 3GPP and ETSI specs. GSMA specs (including SGP.22) are a plus.
• Strong Knowledge of public key cryptography. Blockchain is a strong plus.
• Proficiency in applet code and system health, diagnosis and resolution, and applet test engineering.
• Experience integrating AI models (Claude, Codex, Gemini) into development workflows including IDEs, CLI tools, and CI/CD pipelines.

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