Assembler Developer

SHIRO APPS

Bethesda, MDPosted April 10, 2026
ContractOn-siteMid-level

Required Skills

IBMOSAssemblyJCLCRLQSAMVSAMEndevorControl-MIMFBMFDB2JavaMainframeBatchMigration

Work Authorization

US CitizenGreen Card
  • We are seeking a highly experienced Assembly Language Developer with deep expertise in IBM z/OS mainframe environments, IRS Core Record Layouts (CRL), and legacy system modernization. The ideal candidate will support extraction of business rules from legacy code, assist in code conversion to modern platforms, and work with mission-critical mainframe systems such as IMF (Individual Master File) and BMF (Business Master File).

Key Responsibilities

  • Analyze, maintain, and enhance legacy code written in IBM z/OS assembly language
  • Extract business rules from existing assembly code and support code conversion initiatives
  • Work with IRS Core Record Layouts (CRL) and QSAM data formats for data processing and transformation
  • Collaborate with cross-functional teams to interpret and migrate legacy system logic accurately
  • Use CA Endevor SCM for version control, release management, and secure code handling
  • Utilize BMC Control-M for job scheduling, workflow automation, and batch job monitoring

Required Skills / Experience

  • Bachelor’s degree in Computer Science, Information Systems, or related field

Strong expertise in IBM z/OS assembly language, including

  • Assembly instructions, addressing modes, and data manipulation techniques
  • JCL (Job Control Language) and job processing concepts

Solid understanding of IBM mainframe architecture, including

  • Storage hierarchy (registers, memory, I/O)
  • System Calls (SVCs) and interrupt handling

Experience with IRS Core Record Layouts (CRL) and QSAM/VSAM data formats (preferred)

  • Exposure to IRS IMF or BMF systems (preferred)
  • Proficiency in CA Endevor SCM for software configuration management

Experience with BMC Control-M for job scheduling and automation

  • Strong knowledge of mainframe development tools (debuggers, assemblers, linkers, utilities)
  • Familiarity with DB2 and other legacy data storage systems

Basic understanding of Java programming

  • Object-oriented concepts, syntax, libraries, and frameworks
  • Ability to translate assembly logic into Java constructs (loops, conditionals, functions, design patterns)

Work Authorization

Visa sponsorship may be considered on a case-by-case basis in accordance with applicable laws.