AIX Developer (COBOL)

At IBM Infrastructure & Technology, we design and operate the systems that keep the world running. From high-resiliency mainframes and hybrid cloud platforms to networking, automation, and site reliability. Our teams ensure the performance, security, and scalability that clients and industries depend on every day. Working in Infrastructure & Technology means tackling complex challenges with curiosity and collaboration. You'll work with diverse technologies and colleagues worldwide to deliver resilient, future-ready solutions that power innovation. With continuous learning, career growth, and a supportive culture, IBM provides the opportunities to build expertise and shape the infrastructure that drives progress. This role involves working with complex language semantics and translating them into robust, production-quality compiler implementations. Experience with COBOL, particularly IBM COBOL implementations, is highly valuable. Candidate should be comfortable independently investigating language behavior , interpreting detailed language specifications, making sound technical design decisions, and solving complex problems across the compiler stack. Candidate to demonstrate technical leadership, strong ownership, and the ability to guide design and implementation decisions while collaborating effectively with other experienced engineers. Strong C/C++ — production-quality systems programming Compiler theory and practice — must have built or significantly contributed to a real compiler, interpreter, or static analysis tool Lexer and parser construction — hand-written or tool-generated (e.g. ANTLR, Flex/Bison); understands grammar ambiguity and conflict resolution AST design and semantic analysis — symbol tables, type systems, scope resolution Deep practical COBOL knowledge must have written or maintained production COBOL applications IBM COBOL for AIX or Enterprise COBOL for z/OS — familiarity with IBM-specific extensions and compiler behaviours COBOL data model expertise — PIC clause semantics, COMP/COMP-3/COMP-5 variants, packed decimal arithmetic, REDEFINES, RENAMES, level-number hierarchy Understanding of COBOL runtime behavior — CALL linkage, PERFORM ranges, file I/O semantics Ability to write precise behavioural specifications from the IBM COBOL language reference India Infrastructure & Technology Hybrid Professional Bangalore, IN Bangalore (0063) IBM India Private Limited C++ Common Business-oriented Language Conflict Resolution Construction Design Grammar IBM Advanced Interactive Executive Computer Programming IBM z/Operating System Protection of Clients' Interests Application Security Testing Arithmetic Lexer Semantic Analysis Semantics File Input/Output