IBM Bob AI Coding Agent Targets Legacy Java Migration

IBM quietly launched Bob (bob.ibm.com) on September 4 — an agentic AI SDLC partner that went straight to the top of Hacker News with 260+ points. And unlike the crowd of greenfield vibe-coding tools, Bob's entire wedge is the unglamorous money: legacy modernization.

What shipped

Bob ships as an IDE extension and CLI ("Bob Shell") with three modes — Agent, Ask, Plan — plus subagents that spawn parallel workstreams you approve before they start. It runs in-house models (per HN threads), integrates MCP, and keywords on enterprise concerns: guardrails, approval gates, HIPAA/FedRAMP. Pricing is metered in "Bobcoins": $20/mo Pro for 50, $60 for 180, $200/mo for 1000. Premium add-ons target the real prize: a $20/mo Java Modernization package (Java 8→25, OSV vuln detection, migration diagrams) and a $40/mo IBM i package fluent in RPG and COBOL.

Why it matters

Every other agentic coding vendor fights over greenfield SaaS. IBM is pointing at the multi-trillion-dollar stock of COBOL, RPG, and Java 8 that still runs the world's banks, insurers, and governments. One Blue Pearl testimonial claims a Java 11→25 migration done in 3 days instead of ~30+ — ~90% faster delivery. Demo-able, compliance-ready, priced like a product, not a research preview.

Verdict: Bob is the first serious agentic-coder play for the modernization market — and a signal that the next agent battleground is boring enterprise code, not demos. Watch whether legacy-fluent models (not just tools) become the moat.