Mainframe Assembler Developer -- W2 only

Mainframe Assembler Developer -- W2 only

Foster City, CA (Contract)

Key Responsibilities

Core Development: Modify, develop, and optimize low-level Mainframe Assembler (BAL) code to support updates to the 0120 automated fuel dispenser transaction.

Real-Time Processing: Implement logic changes to adjust pre-authorization amounts and update real transaction amounts in near real-time.

System Integration: Collaborate closely with internal teams and Visa to align client-side changes with Visa’s 0120 confirmation advice, ensuring flawless processing and transaction reversals.

Testing & Debugging: Utilize Xpediter to debug complex Assembler code, isolate defects, and support rigorous unit and integration testing.

Requirement Refinement: Actively participate in flushing out technical requirements alongside client teams, translating business needs into robust technical designs.

Phased Delivery: Support a multi-phase release schedule, ensuring code stability and backward compatibility across deployment phases.

Required Qualifications & Experience

Technical Skills:

15+ years of experience in Mainframe IBM Assembler (BAL) development.

Connex Platform: Deep hands-on experience working within the Connex switching/payment processing environment.

Debugging Tools: Proven expertise using Xpediter for mainframe debugging and troubleshooting.

Payment Systems Knowledge: Strong understanding of financial transaction messaging, specifically automated fuel dispenser (AFD) workflows and pre-authorization/clearing cycles.

Professional Attributes:

Experience working on high-volume, near-real-time transaction processing systems where data integrity is paramount.

Ability to hit the ground running in a fast-paced environment with requirements currently being finalized.

Excellent collaboration skills to seamlessly integrate with existing client teams and coordinate with external networks (Visa).

Preferred Qualifications (Nice to Have)

Familiarity with Visa ISO 8583 messaging standards or similar payment network specifications.

Experience with phased, large-scale migration or deployment strategies in a banking or retail fueling environment.