No. 03 · The observatory

Mechanical Orchard

Migration-led mainframe replacement that sells verified equivalence, not translation.

Status: Open
Case: One of eight recorded cases
Report: Back to the cases chapter

Snapshot: Scored 2026-10-05, reported 2026-10-09
Milestones: 8 recorded, 1 with an exact day
Limits: Partial and unavailable dates stay as recorded text. The timeline plots exact days only.

Mechanical Orchard

Mechanical Orchard replaces custom COBOL estates with code the customer owns. It captures what the running system does, rewrites in slices, and matches bytes. About 100 staff; $95M to $102M raised per filings, depending on seed treatment. It reported over $10M revenue and a profit for 2023; later revenue is undisclosed. It has retired applications, not whole mainframes.

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The market it attacks

The target is the custom z/OS estate: COBOL, JCL, CICS, IMS, Db2, VSAM and more. IBM’s Z platform serves two thirds of the Fortune 100, per its 2022 release. GAO dates critical federal systems at 23 to 60 years, few modernisations finished. A retailer’s $40M transpile ran at a tenth of mainframe speed and never shipped. ISG estimates testing takes over 70% of mainframe migration time. It held 7M lines on 6,000 MIPS across five partitions, dependent on nine engineers. Hidden behaviour lives in schedulers, error paths and CICS conversations. A data request behind the fortress can carry an eight-week SLA. A 150-executive survey found 27% feared job loss from a failed technology bet.

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Origin and the first wedge

Rob Mee founded a software consulting business. He became chief executive of its corporate successor in August 2015. VMware bought that successor for $2.7B in December 2019. A 2020 contact-tracing build-and-run job led through Ratio PBC to MO. MO launched November 2022 with a $7M seed; it says it was founded that October. Kent Beck joined as chief scientist and stepped down in November 2024. The insight: copy a black-box system’s behaviour, then run the copy. A June 2023 GPT-4 pairing experiment passed a test GPT-3 failed, for $6 a run. A late-2024 breakthrough became Imogen; hyperscalers wanted the on-ramp.

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The first customers

The first job was one batch program at the retailer, live June 27, 2023. A March VPN link and delivery pipeline matched full production runs by late April. Batch came first because captured runs double as a test suite. The retailer had failed twice already: a consultancy lift-and-shift, then the transpile. Selling evolved: discovery, then 6-to-8-week pilots, then 8-to-12-week job clusters. A free NDA proof shows about 100,000 tested lines, without access to prospect data. About ten organisations are described publicly; Omni and SulAmérica are named. Emergence says Omni’s core apps moved to cloud in about a year, before its sale. Forward Air bought Omni two weeks before MO named it; Omni vanishes from later material. The April 2026 map lists a bank, an automaker, a manufacturer, a retailer, an insurer. Engineers run old and new side by side until output matches. Later retail jobs reached production at two a week; Thoughtworks partners since 2025. Mee says a 100-person firm cannot run these programmes alone. Sales cycle is unpublished; early deals likely came through the founder’s network. Buyer cynicism runs deep after failed exits; bloop shows the 18-to-24-month risk. AWS Marketplace lists an Imogen unit at $100K a month on a one-month contract.

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How big it is now

Seed $7M, Series A $24M led by Emergence in February 2024. Series B announced at $50M led by GV in August 2024. Filings show the B staying open to $69.17M by January 2026. The total is $95M to $102M depending on whether the A filing counts the seed. Headcount plateaued near 100 from April 2025 through September 2026. Throughput passed 10,000 lines per engineer-week by April 2026. A record run verified 11,578 lines in 28 hours at a major retailer. Channels now include Thoughtworks, Tradewinds, marketplaces, GSA, Carahsoft and Leidos. The retailer retired a global inventory and supply-chain application by September 2024. Engagement-wide, MO reports cycle plus 265%, throughput plus 347%, code down 50-65%. Announced totals and SEC sold figures differ; extensions postdate each announcement. MO was profitable in 2023, then took an unsolicited $50M GV round.

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What made it hard

A pure LLM rewrite misread keyed VSAM, packed decimals, assembler branches and abend codes. The fix is a harness feeding old and new the same input and comparing bytes. Capturing production data is a quarter of MO’s own effort model. One customer’s capture ran to about 600 GB. MO’s worked example uses six months of captured data. Models fail on large programs, so code must first be cut into units. Anthropic’s February 2026 COBOL post cut IBM shares 13% in a day. AWS gives its agent away; Google’s Dual Run is designed to compare in parallel. Verification, MO’s core product, is becoming a hyperscaler feature. Pipelines stall on unaddressable paths or unlicensed utilities, then need legacy readers. An officer on the 2025 filing is absent from 2026’s, suggesting a departure.

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The strategy

It began as build-and-run service, then licensed the hand-run method as Imogen. One analyst calls it software with forward-deployed engineers; a rival says services. The path: batch to job clusters to CICS to applications to the mainframe. Move first, improve later; old and new share data during phased cutover. Human-reviewed output in 2024 became autonomous build-and-verify by July 2026. Independent agents now check output against captured behaviour. A manufacturer moved four warranty jobs across three schemas in four months. Assessment and rules integrations follow; long-run maintenance is the stated ambition. SulAmérica’s 130,000-plus lines are verified and ready, live status unstated. No named customer has publicly switched off a whole mainframe.

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Milestones

March 2023: First engagement begins at Fortune 500 retailer.
June 27, 2023: First batch workload reaches production.
February 2024: Omni Logistics named as early customer.
August 2024: Series B, $50 million led by GV.
September 2024: Retailer inventory application retired.
April 2025: Imogen licensed platform launched.
April 2026: SulAmérica 130K-plus lines verified, ready for production.
April 2026: 11,578 verified lines in 28 hours reported.

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What others can copy

Make the incumbent’s runtime the spec: target zero post-cutover reconciliation defects. Start with the job that killed the last project: under 120 days to first cutover. Sell proof before price: measure proofs of concept converting to paid within two quarters. Sell the layer platforms skip: track the pipeline share co-sold with a hyperscaler. Run the method by hand before productising: track lines replicated per engineer-week. Borrow distribution while small: measure partner-sourced share of new programmes. These are founder tests to run, not results already achieved.

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Open questions

No customer has publicly switched off a whole mainframe. Captured flows can miss seasonal peaks and rare exception paths. HFS reports symbolic suites covering about 99% of code, unaudited. Whether the retailer finished two of its largest remaining applications by January 2026 is open. Whether margins look like software or services is unknown. Hyperscaler verification features commoditise its core product. No public regulator view exists on unreviewed AI-written code. Bug-for-bug fidelity versus later improvement is undocumented at scale. A cited patent was not found; federal channels name no federal customer.

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Limits

Readiness is not a cutover; contracted or verified is not live. Engagement-wide metrics are not single-application results. Filings support a funding range, not a single total. Expected application completions have no public confirmation.

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Exhibit 8Explore · open a case

Milestones in the Mechanical Orchard case

Exact-day events on a UTC timeline, one lane per case.

milestone

How to readEach dot is a dated milestone. Only exact dates draw dots.

NoteMonth- and year-only milestones stay in the tables, never plotted.

SourceLegacy Software Atlas. Frozen scoring snapshot of 5 October 2026. Report version 4 dated 9 October 2026.

Recorded milestones

Every recorded event for this case, in frozen order. Statuses stay as recorded.

Milestone	Date	Status	Sources
First engagement begins at Fortune 500 retailer	March 2023	reported	Mechanical Orchard, Fortune 500 retailer case study, undated, accessed 5 Oct 2026.
First batch workload reaches production	June 27, 2023	reported	Mechanical Orchard, Fortune 500 retailer case study, undated, accessed 5 Oct 2026.
Omni Logistics named as early customer	February 2024	reported	Mechanical Orchard, Series A release, 7 Feb 2024.
Series B, $50 million led by GV	August 2024	reported	Mechanical Orchard secures $50 million release
Retailer inventory application retired	September 2024	reported	Mechanical Orchard, Fortune 500 retailer case study, undated, accessed 5 Oct 2026.
Imogen licensed platform launched	April 2025	reported	Mechanical Orchard, Imogen launch and Thoughtworks partnership release, 3 Apr 2025.
SulAmérica 130K-plus lines verified, ready for production	April 2026	reported	Mechanical Orchard customer presentation at Google Cloud Next 2026 (SulAmerica)
11,578 verified lines in 28 hours reported	April 2026	reported	Mechanical Orchard (Edward Hieatt), first year of Imogen, 27 Apr 2026.

Back to the cases chapter and the full milestone table.