---
id: "lib-2026-11-04-vibe-coding-reaches-enterprise-saas-an-smbc-group"
type: "library"
title: "Vibe coding reaches enterprise SaaS: an SMBC-group lessor uses it for per-customer customisation (エンタープライズSaaSにもバイブコーディングの波　三井住友系が顧客ごとのカスタマイズに活用)"
lang: "JA"
org: "ITmedia AI+ / Sumitomo Mitsui Finance and Leasing"
source_type: "Article"
date: "2026-11-04"
week: "2026-W45"
url: "https://nosov.ai/library/lib-2026-11-04-vibe-coding-reaches-enterprise-saas-an-smbc-group/"
original_url: "https://www.itmedia.co.jp/aiplus/article/2611/06/2000002933/"
tier: "B"
tier_name: "Useful, limited"
tier_reason: "ITmedia AI+ report from the launch press event of Sumitomo Mitsui Finance and Leasing (SMFL) and Replit; first-hand quotes on the control design, but the results are company-reported and partly forecast."
summary_basis: "full-text"
original_minutes: "5"
tags: ["ai technology", "business transformation", "leasing", "software customisation"]
---

# Vibe coding reaches enterprise SaaS: an SMBC-group lessor uses it for per-customer customisation (エンタープライズSaaSにもバイブコーディングの波　三井住友系が顧客ごとのカスタマイズに活用)

Tier B (Useful, limited): ITmedia AI+ report from the launch press event of Sumitomo Mitsui Finance and Leasing (SMFL) and Replit; first-hand quotes on the control design, but the results are company-reported and partly forecast.

Summary based on the full text.

## In short

ITmedia AI+ (6 November 2026) covers SMFL, a leasing company jointly owned by SMBC Group and Sumitomo Corporation, which on 4 November announced "enterprise vibe coding" built on Replit and a "personalised SaaS" for corporate clients. Clients can have its asset-management service assetforce customised through natural-language app building. SMFL put a gateway between Replit and assetforce, split context per task to save tokens, and checks generated code with a quality-control agent running deterministic tests, with an SMFL engineer approving every change.

## Key numbers

- 6 people x ~6 months to 1 person x 1 week: assetforce modification estimated under the old method versus done with enterprise vibe coding
- 1/3: expected development and test time after requirements for a 200+-screen depreciation system, versus the old method
- 200+: companies with paid contracts for SMFL's asset-management cloud service assetforce
- 10x in 5 years: SMFL's revenue target for its digital services

## What it reports

- SMFL holds about 9 trillion yen of operating assets. It gained an in-house development team when it bought GE Japan's leasing arm in 2016; assetforce went on sale in 2021 and has paid contracts with more than 200 companies.
- Customising assetforce for each client's requests was costly; Replit was chosen to cut that effort.
- A development platform (ADP) connects assetforce and Replit, checks authentication and permissions on both sides and passes only data and operations the client has allowed.
- Context is split by work unit so each developer's AI session receives only the design information needed, to stop token use ballooning in multi-person projects.
- A quality-control agent independently verifies AI-written code with deterministic tests; an SMFL engineer always reviews before release, and final decisions are not delegated to AI.
- Claimed results: an assetforce change estimated at 6 people for about half a year was done by 1 person in 1 week; a 200+-screen depreciation system is expected to need one third of the usual development and test time after requirements.
- Replit CEO Amjad Masad argues vibe coding reduces dependence on individual developers because AI writes in a more standard style. SMFL concedes a risk of over-personalising systems and is training forward deployed engineers.

## How they got it

A reporter's account of the press event, with quotes from SMFL president Tetsuro Imaeda and Replit's CEO and slides from SMFL. No measurement method is given for the time savings.

## Limits

- All results are self-reported at a product launch; the depreciation-system figure is a forecast.
- The 6-person, half-year baseline is an estimate, not a measured project.
- No data on defects, running cost or maintenance after release.

## Why it matters for companies

A regulated financial-group company is putting natural-language app building in front of its own clients, with explicit controls: a permission gateway, deterministic tests by a separate agent, and a human sign-off. That control pattern is reusable for any firm letting non-developers build on top of core systems. SMFL's own point that requirements matter more once coding is cheap fits the wider evidence. Treat the 6-people-to-1 figure as a launch claim.

## Key passages in translation

> 金融や会計を扱うシステムでは、計算結果が正しいこと、その計算根拠を説明できることが欠かせない

In systems that handle finance and accounting, it is essential that calculation results are correct and that the basis for the calculation can be explained.

> assetforceの改修では、従来手法では6人で約半年かかると見込んでいた開発を、1人・1週間で完了した。

In the assetforce modification, development that was expected to take six people about half a year with conventional methods was completed by one person in one week.

> 最後は必ず同社のエンジニアが確認してからassetforceに実装するものとし、AIに最終判断を委ねないことを開発のポリシーとしているという。

The final step is always a check by one of the company's engineers before release to assetforce; not leaving the final decision to AI is its development policy.

Original: https://www.itmedia.co.jp/aiplus/article/2611/06/2000002933/