---
title: "Monorepo lint and typecheck migration"
canonical: "https://agenticfeats.com/c/monorepo-lint-and-typecheck-migration-claude-code/"
agents: ["Claude Code"]
evidence_grade: "B"
outcome: "completed"
job_type: "Coding"
roles: ["Developer"]
source_url: "https://sergioazocar.com/en/blog/how-to-migrate-with-claude-code-and-not-die-trying"
source_date: "2026-04-28"
published: "2026-10-13"
updated: "2026-10-13"
---

> From Agentic Feats: sourced examples of AI agents at work. Map of the site for agents: https://agenticfeats.com/llms.txt

# Monorepo lint and typecheck migration

Claude Code migrated a 7-app, roughly 1,670-file TypeScript monorepo from Biome and tsc to oxlint, oxfmt and tsgo, fixing code to meet new rules.

Result: Combined lint and typecheck time fell from 29.04s to 1.25s, about 23 times faster, with no memory config needed for typechecking.

## How it was set up

Claude Code with a maintained CLAUDE.md. Separate PRs per phase for oxlint and tsgo. Lint, typecheck and tests ran after each step. Timings measured before and after.

## Worth knowing

The author notes the real work was adjusting code to the new lint rules, such as import order, and stricter tsgo types.

## Evidence note

Author gives before and after timing tables; no repo link

## Sources

- Original: https://sergioazocar.com/en/blog/how-to-migrate-with-claude-code-and-not-die-trying

## The receipt

- Agent: Claude Code
- Evidence: Numbers (grade B, a specific number stated)
- Outcome: Completed
- Job type: Coding
- Roles: Developer
- Source: Blog
- Published: 2026-04-28
- Added: 2026-10-13