Lead JavaCard Engineer

Role overview

You will serve as a lead engineer focused on JavaCard and secure element development for a major global financial services client. The solution involves building applets that run inside secure hardware and interact with a companion iOS host application, enabling contactless payment flows at point of sale.

This work demands strong expertise in GlobalPlatform standards, APDU handling, and cryptographic processing on constrained devices. If you have already delivered JavaCard applets into production secure elements, this role places that experience at the center of a high-scale payment environment.

Business context

The applet you develop will act as the software layer that bridges a payment device and a terminal when a customer taps to pay. Your work will influence both the security and interoperability of payment credentials on secure element hardware at scale.

The engagement also supports growth in multi-scheme payment capability beyond the client’s current payment portfolio.

Key responsibilities

• Architect and build JavaCard applets for secure element deployment in contactless payment scenarios.
• Implement APDU request and response flows according to ISO 7816 and the GlobalPlatform Card Specification, including SELECT, INITIALIZE UPDATE, EXTERNAL AUTHENTICATE, GET DATA, and GENERATE AC.
• Oversee the secure element applet lifecycle, including installation, personalization, key injection, and deletion in line with GlobalPlatform requirements.
• Create personalization scripts and key injection procedures used to provision payment credentials on the target secure element hardware.
• Test the terminal communication layer at the tap-to-pay boundary and confirm correct cryptogram exchange with EMV-compliant terminals.
• Partner with the iOS engineering team to keep the payment flow aligned from the Core NFC host application through terminal cryptogram validation at the secure element boundary.
• Prepare technical documentation covering applet design, key management, APDU commands, and integration touchpoints.
• Work within Agile ceremonies and adapt to the client’s engineering processes, tools, and standards.

Requirements

• At least 8 years of overall engineering experience, including 3 or more years building JavaCard applets that have been shipped to production secure elements.
• Hands-on experience with GlobalPlatform Card Specification versions 2.x or 2.3.x, including secure channels, card content management, and lifecycle operations.
• Strong command of ISO 7816 APDU protocol design and implementation, including status words and extended APDUs.
• Practical experience with JavaCard 3.0.x, including JCRE runtime behavior, package structure, persistent and transient object management, and cryptographic APIs such as javacard.security and javacardx.crypto.
• Experience in payment credential personalization, including key injection, key diversification, and personalization script creation for production secure element deployments.
• Understanding of EMV contactless payment flows and the way secure element applets interact with point-of-sale terminal infrastructure.
• Ability to build reliably on constrained hardware, taking into account memory limits, transactional integrity, and applet sizing constraints.

Nice-to-have experience

• Familiarity with iOS Core NFC, including NFCTagReaderSession and NFCISO7816Tag, for APDU exchange from the host application.
• Basic reading knowledge of Swift or Objective-C to support integration and troubleshooting with the iOS team.
• Exposure to Mastercard M/Chip, Visa payWave, or similar contactless payment network specifications.
• Experience with GlobalPlatform Trusted Execution Environment environments in addition to secure elements.
• Hands-on use of JavaCard test tools or simulation environments such as jCardSim.
• Awareness of payment scheme certification processes such as EMVCo or comparable certifications.
• Willingness to work from or relocate to Pune or Bangalore, India.

Consultant expectations

• Use strategic judgment by understanding that the applet supports live tap-to-pay expansion rather than isolated research and development.
• Take ownership of applet quality, personalization accuracy, and terminal interoperability, including diagnosis when issues appear at the terminal boundary.
• Align closely with client stakeholders and iOS engineers, and explain secure element concepts and APDU constraints in clear, non-technical language when needed.
• Focus on measurable results such as interoperability, cryptogram correctness, and personalization reliability rather than activity alone.
• Bring structure to ambiguous requirements, ask constructive questions, and work productively in an evolving program environment.

Company overview

Luminary Digital operates as a product engineering and AI transformation firm with a strong emphasis on AI-native delivery, engineering excellence, and measurable client outcomes. The organization describes a culture built around drive, accountability, clear communication, and a bias toward outcomes over activity.

Additional information

Location: Pune, India

Compensation: INR 3,000,000 to 4,000,000 per year

Openings: Not specified

Eligibility: Candidates with a B.C.A., B.Arch., B.Com., B.Tech / B.E., or B.Sc. in any specialization may apply.

Employment arrangement: The posting does not specify a standard employment type.

Start date, application deadline, and duration are not provided.

No separate perks, stipend details, or opening count were listed in the source.

Working style

The role is based in Pune and is oriented around collaboration with both the client engineering team and the iOS host-side team. The responsibilities imply onsite coordination and close technical interaction across payment, secure element, and mobile integration workstreams.