Top 12 Cobol Programmer Skills to Put on Your Resume
In the evolving landscape of software development, COBOL programmers remain in demand, especially in industries where legacy systems carry the load and must not fail. To stand out in this niche, you need a resume that spotlights the skills that matter—technical depth, disciplined change control, and the knack for adapting old pillars to new demands without breaking what already works.
Cobol Programmer Skills
1. COBOL
COBOL (Common Business-Oriented Language) is a high-level language built for business, finance, and administrative systems across enterprises and governments. It’s legible, sturdy, and excellent at chewing through large volumes of transactional data.
Why It's Important
COBOL underpins core systems that move money, pay claims, calculate pensions, and close the books. As a COBOL programmer, you keep critical workloads humming—accurately, predictably, and at scale—while modernizing where it counts.
How to Improve COBOL Skills
Strengthen fundamentals, then layer on modern tooling and habits that keep code resilient:
Lean into best practices: Structured programming, clean data divisions, clear copybooks, and meaningful names. Tighten I/O and minimize passes through data.
Know modern COBOL: Learn current compiler features, intrinsic functions, and diagnostics. Newer compilers offer optimizations that shave CPU and simplify code.
Work in an IDE: Use an environment with syntax checking, debugging, and code analysis. Faster feedback, fewer slips.
Use version control: Git for branching, review, and traceability. Treat JCL, PROCs, and copybooks like code—because they are.
Join practitioner communities: Mainframe user groups, forums, and meetups help you learn quirks, patterns, and real fixes.
Practice deliberately: Build small utilities, refactor legacy modules, write unit-like tests with stubs, and review production abend reports to sharpen instincts.
Study real code: Scan open examples and internal repositories. Patterns stick.
Keep learning: Courses, books, and internal lunch-and-learns. Refresh often; habits calcify.
How to Display COBOL Skills on Your Resume
2. JCL
JCL (Job Control Language) tells the mainframe how to run batch work: what programs to execute, which datasets to touch, how to sort, and when to stop or go on.
Why It's Important
For COBOL workloads, JCL is the launchpad and the guardrail. It shapes throughput, resource use, restart behavior, and the sanity of overnight cycles.
How to Improve JCL Skills
Tune for clarity and control. Waste less I/O. Avoid surprises:
Name jobs and steps clearly: Purpose-first naming pays off at 2 a.m.
Trim and merge steps: Remove no-op phases; combine compatible operations.
Comment and format: Future you (and operators) will thank you.
Parameterize: Symbolic parameters beat hardcoded paths and dates.
Use condition codes: Control flow precisely with IF/THEN/ELSE and return codes.
Centralize common pieces: JCLLIB and INCLUDE members cut duplication.
Right-size datasets: Space, BUFNO, LRECL, and RECFM tuned to access patterns.
Lean on utilities smartly: SORT, IEBGENER, IEBCOPY, and friends save CPU when used well.
Evolve continuously: Review abends, SMF metrics, and operations feedback; iterate.
How to Display JCL Skills on Your Resume
3. DB2
DB2 (commonly styled Db2) is IBM’s relational database on the mainframe and beyond. COBOL programs frequently embed SQL to query and update Db2 tables, binding business logic to reliable transactional storage.
Why It's Important
Db2 supplies consistent performance, atomicity, and scale for COBOL applications that manage critical data flows—billing, ledgers, customer profiles, you name it.
How to Improve DB2 Skills
Focus on access paths, statistics, and code patterns:
Write tight SQL: Select only what you need, push filters early, choose joins deliberately, avoid “SELECT *”.
Index with intent: Design indexes for frequent predicates and join columns; avoid blanket indexing that slows writes.
Design for access: Normalize to reduce redundancy, denormalize sparingly when access patterns demand fewer joins.
Cluster data: Keep related rows close to cut I/O churn.
Tune buffers: Size buffer pools based on hot objects and workloads.
Read the explain: Inspect access paths and adjust SQL or indexing when the optimizer disagrees with your intent.
Maintain regularly: RUNSTATS, REORG, and REBIND keep the optimizer honest and objects healthy.
Code for efficiency: Manage cursors carefully, batch commits appropriately, and avoid chatty calls.
How to Display DB2 Skills on Your Resume
4. CICS
CICS (Customer Information Control System) is a high-throughput transaction monitor. It runs online COBOL applications that must respond in milliseconds while touching files, messages, and databases safely.
Why It's Important
CICS gives COBOL applications a durable, scalable home for interactive workloads—banking, insurance, retail, transportation—where uptime and speed matter.
How to Improve CICS Skills
Chop latency, simplify code paths, and watch resources closely:
Streamline data access: Keep SQL lean; minimize round trips to Db2 and file systems.
Use resources wisely: Reduce temporary storage churn; employ transient data queues where they fit.
Write efficient COBOL: Clear conditions, compact logic, minimal conversions; remove dead branches.
Partition work: Parallelize independent tasks to boost throughput when the design allows.
Adopt new features: Modern CICS capabilities (policies, events, APIs) can simplify plumbing and observability.
Debug proactively: Use region-friendly traces and targeted diagnostics to cut mean time to resolution.
Monitor and tune: Track response times, queue depths, and storage; fix bottlenecks before users feel them.
How to Display CICS Skills on Your Resume
5. VSAM
VSAM (Virtual Storage Access Method) provides indexed, sequential, and relative file organizations on IBM mainframes. COBOL programs use VSAM for fast, reliable access to business-critical datasets.
Why It's Important
VSAM is the backbone for many legacy files that simply must perform: predictable reads, orderly updates, and safe recovery.
How to Improve VSAM Skills
Design files for how they’re read and written—not just how they’re stored:
Pick the right organization: KSDS, ESDS, or RRDS based on access patterns and keys.
Tune buffering: Adjust buffers and block sizes to cut I/Os on hot paths.
Leverage alternate indexes: Add AIX selectively for frequent secondary lookups.
Compress where sensible: Save disk and sometimes I/O, but measure CPU trade-offs.
Reorganize regularly: REPRO and recluster to handle growth, splits, and fragmentation.
Design for concurrency: Partition workloads where possible; reduce contention.
Write tidy I/O: In COBOL, set ACCESS MODE and RECORD KEY explicitly; minimize random probes.
How to Display VSAM Skills on Your Resume
6. IMS DB/DC
IMS DB/DC is a hierarchical database and transaction manager. COBOL applications use it for screaming-fast, predictable access paths and robust online processing.
Why It's Important
When the data model fits a hierarchy, IMS delivers reliability and performance that’s hard to beat, especially for high-volume OLTP.
How to Improve IMS DB/DC Skills
Shape the hierarchy to the workload, then tame I/O:
Design for path length: Use secondary indexes prudently; consider partitioning for very large datasets.
Choose access methods wisely: Direct versus sequential access depends on the query shape—opt for the shortest route.
Tune buffers: Size pools to fit hot segments and reduce physical reads.
Use Fast Path where it fits: For blistering transaction rates, choose Fast Path databases and structures.
Optimize COBOL logic: Batch related calls, avoid unnecessary gets, and simplify loops.
Parallelize carefully: Distribute workloads to reduce contention and shorten queues.
Manage transactions cleanly: Keep units of work tight to minimize locks and wait chains.
Maintain on a cadence: Reorganize, purge debris, and refresh statistics to hold performance steady.
How to Display IMS DB/DC Skills on Your Resume
7. SQL
SQL (Structured Query Language) is the standard for defining, querying, and changing data in relational databases.
Why It's Important
COBOL systems frequently sit on relational stores. SQL lets you fetch, join, and persist data cleanly without writing bespoke file logic for every scenario.
How to Improve SQL Skills
Build from basics, then think like the optimizer:
Master fundamentals: SELECT, WHERE, JOINs, GROUP BY, and set-based thinking.
Practice often: Use real datasets, recreate reports, and compare plans before and after tweaks.
Embed SQL in COBOL well: Handle cursors thoughtfully, reduce chatty calls, and batch changes when safe.
Learn indexing: Cardinality, covering indexes, and composite keys—all with measurement, not guesswork.
Go advanced when ready: Stored procedures, triggers, window functions, and error handling.
Engage with peers: Discuss tricky joins, edge-case nulls, and performance puzzles with practitioners.
How to Display SQL Skills on Your Resume
8. Mainframe
A mainframe is a high-capacity system for large-scale batch and transactional computing. For COBOL programmers, it’s the platform where dependability, throughput, and data integrity take center stage.
Why It's Important
Mainframes process immense workloads with security and consistency. They’re built for the mission-critical jobs COBOL is famous for.
How to Improve Mainframe Skills
Blend coding discipline with modern tooling and operational awareness:
Optimize COBOL: Profile hot paths, remove redundant moves and conversions, and tighten loops.
Adopt modern tooling: Use contemporary IDEs, source analysis, automated testing, and pipelines where available.
Partner with systems teams: WLM settings, memory, and I/O config shape your program’s fate—coordinate.
Keep learning: Track compiler advances, runtime changes, and operations best practices.
Use an integrated dev environment: Better edit/compile/debug cycles reduce defects and speed delivery.
Design smart data access: Prefer indexed access and efficient database calls; minimize random I/O.
How to Display Mainframe Skills on Your Resume
9. TSO/ISPF
TSO (Time Sharing Option) provides an interactive shell on IBM mainframes. ISPF layers on a menu-driven interface for editing, browsing datasets, compiling, and navigating system tools—perfect for day-to-day COBOL development.
Why It's Important
TSO/ISPF is the workbench. Edit, submit, review, and fix—all from the same cockpit.
How to Improve TSO/ISPF Skills
Customize, memorize, and automate:
Learn keystrokes: Line commands, primary commands, and quick jumps save hours.
Tune your profile: Tailor settings, colors, and panel behaviors to speed your flow.
Use editor macros: Automate repetitive edits, reformatting, tagging, and validations.
Lean on PDF features: Streamline compile, link, and debug cycles with integrated facilities.
Stay current: New panels and tweaks arrive over time—adopt what helps.
How to Display TSO/ISPF Skills on Your Resume
10. PL/I
PL/I (Programming Language One) blends business processing with scientific and systems features. For a COBOL programmer, it opens doors to richer data structures and expressive control flow while still feeling practical for enterprise work.
Why It's Important
PL/I offers power where COBOL can feel rigid—advanced data types, strong string handling, and flexible control structures—handy for complex integrations and utilities.
How to Improve PL/I Skills
Bridge what you know in COBOL to PL/I’s style:
Grasp syntax differences: Blocks, scope, and expressions read differently—practice small examples.
Study data types: Explore structures, arrays, and strings; map them mentally to COBOL equivalents.
Master file I/O: Learn PL/I stream and record models; compare to COBOL’s file control.
Use control flow well: Condition handling and loops can simplify gnarly logic.
Lean on libraries: Built-ins for math, string, and date/time trim code bulk.
Practice by porting: Convert small COBOL programs to PL/I to build intuition.
Helpful references: IBM PL/I Language Reference; PL/I for COBOL Programmers; university course materials that cover PL/I fundamentals.
How to Display PL/I Skills on Your Resume
11. REXX
REXX is a concise scripting language prized for readability. It excels at glue tasks, text processing, and automation that orbit your COBOL programs.
Why It's Important
Automate the boring stuff. REXX speeds up dataset housekeeping, report generation, pre/post-processing, and orchestration around batch flows.
How to Improve REXX Skills
Think scripts, not systems—and iterate fast:
Learn the idioms: Dynamic typing, straightforward parsing, and simple error handling make quick work of chores.
Practice string and file ops: Read, slice, rewrite, and stitch data without fuss.
Use built-ins: Built-in functions replace verbose loops; favor them.
Automate workflows: Drive utilities, call programs, and wrap JCL submissions to reduce manual steps.
Integrate with COBOL: Use REXX as a harness for test data prep, log parsing, and environment setup.
Engage communities: Swap snippets, patterns, and tips to level up quickly.
How to Display REXX Skills on Your Resume
12. Z/OS
z/OS is IBM’s 64-bit mainframe operating system, engineered for throughput, security, and rock-solid reliability. It’s where large COBOL estates live.
Why It's Important
z/OS delivers the availability and performance guarantees that mission-critical COBOL applications demand—batch by night, transactions all day.
How to Improve Z/OS Skills
Write efficient programs and cooperate with the platform:
Optimize COBOL with current compilers: Enable performance options; adopt modern language features when appropriate.
Stay current on runtimes: Compiler and runtime updates often bring tangible CPU and diagnostics improvements.
Leverage platform features: Dataset buffering, specialty engines like zIIP, and high-performance sort utilities can move the needle.
Design for parallelism: Exploit partitioning and multi-step flows; take advantage of Parallel Sysplex where applicable.
Tune database use: For Db2-heavy apps, align SQL and commits with system goals.
Measure relentlessly: Use performance monitors to spot hotspots, I/O churn, and contention—then fix with focus.
Keep learning: Track z/OS and COBOL enhancements, and fold them into your practices.
How to Display Z/OS Skills on Your Resume
