Agentic modernization, delivered. Accurate, complete, on time.
Mainframe Modernization Services: Staged, Validated, Delivered
The business rules leave the mainframe. The risk doesn't come with them.
Swimm’s mainframe modernization services take on the systems no one wants to touch: we extract the business rules, map the dependencies, and deliver modernization in validated stages — as an expert engagement, not a conversion tool. Swimm is a product-enabled service company. We combine deterministic analysis for accuracy, AI for scale, and SMEs to catch what tools miss.
The problem
The mainframe isn't getting easier to modernize
The mainframe isn't getting easier to modernize while you wait — it's getting harder.
01
The people who understand the system are retiring. Every year, the number of people who can explain why the system works the way it does gets smaller.
02
Business rules have gone undocumented for decades. The logic that runs the business exists only in code written before most of your current team started.
03
Rewrite attempts fail on hidden dependencies. Projects that skip a real dependency map tend to discover the hard way what they missed.
04
Standing still costs more every year. The system doesn't get cheaper to modernize by waiting — it gets more expensive and more fragile.
How it works
Three layers, working together
01 · Deterministic
Deterministic analysis establishes ground truth
Deterministic analysis maps dependencies, data flows, and dead code across the mainframe environment before anything moves.
02 · AI
AI coordinates context at scale
AI applies verified patterns to accelerate the work at scale.
03 · SME
SMEs validate before it ships
SMEs validate every extracted rule and every deliverable, adding the know-how that's about to walk out the door and catching what automated analysis alone can't.
Deterministic → AI → SME
A staged engagement
01
Assessment
A snapshot of the mainframe estate and a scoped plan with risks and success criteria.
02
Specification
Extracts the business rules, flows, and system behavior your team and agents need — documented before that knowledge retires.
03
Modernization
Executes the staged change with SME validation throughout.
04
Enablement
Hands off playbooks, training, and knowledge base access.
A workspace, not a stack of files
Every deliverable lives in one place. Yours to keep, queryable by your tools.
Delivered change
- Extracted services and APIs
- Refactored web and mobile clients
- API contracts and schemas
- One source of truth for business logic
System understanding
- Logic distribution map
- Architecture and dependency maps
- Dead-code and duplication analysis
- Critical flow documentation
- Queryable by MCP
Enablement assets
- Parity test suite
- Extraction playbooks
- Team training
- Queryable knowledge base
Proof
Validation evidence, not claims
Works with the tools you've already chosen
Methodology built and led by Swimm's founders — Oren, CEO · Gilad, CTO. Every deliverable ships with validation evidence.
Frequently asked questions
Is Swimm's mainframe modernization automated conversion or a service?
It’s a full-service engagement — automation is anchored in deterministic analysis, but humans validate everything before it ships. This isn’t a conversion tool you run yourself.
How does Swimm capture business rules our SMEs are retiring with?
Through a combination of deterministic extraction from the code and direct SME interviews — the Specification stage documents the rules, flows, and behavior before that knowledge leaves with the people who hold it.
Can mainframe modernization be done in stages?
Yes — Assessment, Specification, Modernization, and Enablement each stand on their own and build on the last, so you’re never committing to the whole project at once.
How do we know the modernized system behaves like the original?
Validation evidence, test plans, and SME sign-off are delivered at every step — the goal is behavioral equivalence you can verify, not just code that compiles.
What if we only want to understand the mainframe first?
Assessment and Specification deliver real system understanding on their own — a snapshot, a scoped plan, and documented rules and flows — even if you go no further.
Staged, validated mainframe modernization
30 minutes. Tell us what's on the mainframe — we'll tell you what a staged path looks like.
Talk directly to our founders: Oren, CEO · oren@swimm.io — Gilad, CTO · gilad@swimm.io