Your legacy system shouldn't hold you back.
We build what you need, grounded in your existing system, and leave your team an agent-ready foundation to keep building on, with Swimm or on their own.
Uncertainty about your legacy system keeps you standing still.
01
Legacy is where you get stuck.Your teams are building fast with AI. The legacy system underneath holds them back.
02
Your system is a black box.Every release adds to it. The rules are buried in the code. Where do you start?
03
Modernization has felt too risky to start.Too slow, too costly, and your best people tied up on the system you run on.
04
Now it's within reach.A verified understanding of your system, with AI agents doing the heavy lifting: less risk, less cost, faster to market.
Is your stack expiring?
Enter your stack and see what is reaching end of life. Launching soon.
Build it. Understand it. Make it agent-ready.
Start where you need it most. Each service is complete on its own, and all three stand on the same verified map of your code.
Application Delivery
Build and deliver the application your business needs
The application your business is waiting for, built on a verified understanding of your current system, with tests that show every rule carried over.
System Intelligence
Capture what your system really does
Open up the black box: every business rule, flow and dependency, mapped from the code and checked by experts who know your domain.
AI Operability
Make your system ready for agentic development
Let your team build with coding agents on legacy code. We prepare your codebase and environment, with verified context, workflows and guardrails.
Start with any service, and stop after any service. The map carries over, so nothing is done twice.
One verified map of your system, under everything we build.
It turns the black box into something your people can read. Built from your code: every flow and dependency indexed from the source, every business rule explained and verified by our experts. All three services stand on it.
- Complete: 100% coverage on supported stacks.
- Verified: 95%+ accurate as a representation of your system.
- Current: in sync with every commit, through our patented selective updates.
What it powers
The grounding layer
Your code
Grounded in your code, at every step.
It starts small, on a sample of your code, so you see what we can do before you commit. It ends with a new application your team keeps building on.
Grounding sample
One week on a sample of your code, so you see what we can do on your own system.
The grounding layer
Our engine maps every flow to 100% coverage before any AI runs. Experts verify every rule.
The new application
Engineers and agents build it module by module, with tests proving every rule carried over.
Your agents at work
Your team and their agents keep building on it, in sync with every commit.
Every finding traces back to the line of code it came from
See it work on your own code before you commit.
Every engagement starts with a grounding sample: one week on a sample of your code.
Your team keeps a living map of the system.
After the project, the grounding layer lives on in the Swimm platform: every flow, rule, term and spec, traced to the code and kept in sync as the code changes.
- Engineers search a flow and follow each step down to the line of code.
- Analysts and SMEs read business rules in plain English and confirm the terms only they know.
- Coding agents query it through MCP, so they work from verified facts.
- Leaders see coverage and progress while the work is underway.
You own what we build; we're there when you want to go further.
Flows / Payments
Late payment
A late fee applies when payment arrives more than 15 days after the due date, unless the account is on a hardship plan.
billing/LATEFEE.cbl · lines 412 to 431
Experts in the loop, at every step.
Forward-deployed engineers
They build the new application with our agents, side by side with your team.
Subject-matter experts
They know your domain, from finance to healthcare, and verify every rule we extract.
AI experts
They get your system ready for coding agents, with the context, workflows and guardrails agents need.
3B+
lines of code analyzed
100%
codebase coverage on supported stacks
95%+
accuracy of the representation
Deployed where modernization is hardest
Security certified
SOC 2 and ISO 27001
On-premise deployment
Including air-gapped environments
Customer-managed LLMs
Your data stays in your control
Mainframe and legacy coverage
COBOL, JCL, PL/I and modern languages
Stays current
Patented updates keep the map in step with your code
Code, not data
We work from code and schemas, never production data
Gartner Cool Vendor 2024AI-Augmented Development and Testing
Frequently asked questions
What does Swimm do?
Swimm delivers agentic modernization as a service. We build and deliver the new application your business needs, grounded in a verified understanding of what your legacy system does, rule by rule. We also make your system ready for agentic development, so your engineers and their coding agents keep building with verified context.
Do you build the new application, or only analyze the old one?
We build it. Our Application Delivery service delivers working, tested software, built by our engineers and agents on top of a complete map of the old system.
How is this different from pointing an AI coding tool at our code?
AI tools read files, so they rarely see a whole flow, and nothing tells you what they missed. We map the code deterministically first, to 100% coverage on supported stacks, and our experts verify the result. Your agents then work from that verified map.
Which languages and stacks do you cover?
Mainframe and legacy languages such as COBOL, JCL and PL/I, and modern stacks such as Java and .NET. Tell us what you run on the scoping call and we will confirm coverage for your code.
Where does our code go?
Work starts under NDA. We can run on-premise, including air-gapped environments, with your own LLMs, and we work from code and schemas, never production data. Security details.
How do we start?
With a scoping call, then a grounding sample: in one week we build the grounding layer on a sample of your code, so you see what we can do on your own system.
What do we keep at the end?
The new code, the specs and the verified map of your system, live in the Swimm platform for your people and your agents. You own what we build; we're there when you want to go further.
Hand us the application you've been wrestling with.
30 minutes with our team. We'll talk through your system and the best place to start.