Modernization track · Core · self-paced ~20h with labs (3 days as a cohort) · prerequisite: CS100 and CS510 Sessions 1–4 (or Java basics); CS150 helpful
The dominant disposition nobody teaches: the mainframe stays the system of record while CICS programs are exposed as APIs with copybook-derived contracts, the batch chain emits events over MQ, data is replicated by change capture into a PostgreSQL replica and reconciled, and new Java services take over function by function behind a router with rollback — plus the governance (reconciliation register, security across the seam, cost honesty) that keeps a multi-year programme controlled. 30 short videos (about 3h50m) on CardDemo’s CICS programs, nightly chain, MQ trigger flow and VSAM data. Every lesson refers back to the AWS CardDemo application running live on SteelFrame — its COBOL source, batch jobs, CICS screens and VSAM/DB2 data — and every lab starts on the mainframe side: you run the legacy program under your own user to produce the golden, then make the Java match it.
Self-paced available Cohort
Open for enrollment now. The lesson videos for this course are in production — release order across the track: CS510 → CS520 → CS530 → CS521 → CS535 → CS500 → CS550 → CS525 → CS540 → CS545 — and every session below is published as its lessons and lab now and marked Coming soon until its videos are released.
Plans: Free individual at no cost, or Paid individual at $349 per course, one-time — code review, extra exercises, grading and priority support.
Every session ends in a lab on your own environment. Labs are machine-checked against expected outputs — you and your L&D team always know exactly where you stand.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. The surveys and the banks — Kyndryl’s "hybrid dominant", ISG’s multi-year programmes, Bradesco/Caixa, the Singapore cores — opening on COACTVW as the system of record that stays; the strangler fig — transform, coexist, eliminate — with analysis_graph as the map; the integration menu — API, message, CDC, file, federation, dual write — and when each lies to you, on SteelFrame’s MQ queues, datasets and DB2 tables; the market’s tools named not endorsed, with the CICS program a z/OS Connect role would expose on 3270.
LAB Map every CardDemo function to an integration pattern, its seam, its first-move order and the reconciliation that will prove it.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. The COMMAREA (COCOM01Y) as the API contract and copybook-to-JSON-schema generation; the façade — a Spring service calling COACTVWC through cics_link with the same bytes behind it as the 3270 screen; program APIs vs screen-flow APIs — a BMS change breaking a scraped flow while the program API survives; the packed field that arrived as text, caught against decode_records.
LAB Gate 1: account view and card list as REST over CICS, OpenAPI published, contract tests green against ten cics_run_script scenarios and decode_records field by field.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. MQ as the seam — request/reply vs fire-and-forget and CardDemo’s CICS trigger flow on SteelFrame MQ; Kafka-shaped topics bridged from MQ with ordering, partitions and idempotent consumers; the transaction-posted event emitted from the batch chain — POSTTRAN publishing 262 messages; replay and poison messages with a dead-letter queue.
LAB Gate 2: posted transactions streamed to a Java notifier — 262 notifications, idempotent, one poison dead-lettered, counts reconciled against the TRANSACT after-image.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. CDC concepts — log-based, trigger-based, snapshot-diff — with the changed bytes of a 3270 update in hex; the change feed to a PostgreSQL replica, built today as snapshot-diff of two export_state captures and honestly labelled; lag, ordering and reconciliation queries with the in-flight false alarm classified; dual-write drift — the record written twice, differently — and why the replica comes from the record, never the writer.
LAB Gate 3: ACCTDATA, CARDXREF and TRANSACT replicated per cycle and reconciled nightly; three injected drifts caught, zero false alarms after classification.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. Routing by function with feature flags, reads first then writes, CCLI on 3270 still serving while the router reads from Java; flipping one function and the overlap reconciliation with 3270 writes still landing; the rollback rehearsal under scripted 3270 traffic; observability across both sides — JESMSGLG and SMF beside logs, metrics and traces — one transaction correlated across the seam.
LAB Gate 4: card list flipped to Java, overlap reconciliation green for the simulated day, rollback under traffic with zero failures, re-flip.
Coming soon The videos for this session are being produced; its lessons and lab are published here now.
Five videos. The reconciliation register with owners and expiry, its queries run on SteelFrame; security across the seam — RACF identities mapped to Spring Security roles, a denial on both sides for the same user; cost honesty — the chain’s CPU in JESMSGLG as the bill that does not fall and the stop criterion; the capstone and the certificate.
LAB Capstone: hybrid CardDemo — façade, events, replica, one function flipped with rollback, register and security mapping — in one evidence pack with capture ids that resolve under your userid; the 25-question check (80%).
CobolStack Certificate — Hybrid Modernization & Coexistence (CS535) is issued from the lab harness’s own record of your runs — not from attendance. To earn it you must clear every gate below:
The certificate attests that you can build and govern the coexistence layer around a mainframe that stays the system of record — APIs, events, change capture, routing and reconciliation — the integration engineering the z/OS Connect and hybrid-bank postings describe, proven against the live estate.
Your seat is a private, full z/OS-compatible environment with the AWS CardDemo estate (COBOL, JCL, CICS/BMS, VSAM, DB2) and the SteelFrame oracle tools (run_capture, export_state, cics_run_script), beside your own Java 21 + Maven + PostgreSQL toolchain; SteelFrame MQ (queue manager CSQ9), cics_link, a PostgreSQL replica in the browser — nothing to install, snapshot and reset per exercise. By the end of the course the lab harness will have verified: four gates — account view and card list as REST over CICS through cics_link with contract tests green; posted transactions streamed from the batch chain over MQ to a Java notifier with counts reconciled and a poison message dead-lettered; a PostgreSQL replica reconciled nightly with three injected drifts caught; the card list flipped to Java and rolled back under 3270 traffic — and the capstone: hybrid CardDemo with one function on Java and an evidence pack.