---
title: "Legacy Code Rewrite & Performance Optimization | BudgetWorks"
description: "Rewrite legacy server code for high performance at lower cost. Modernize PHP, Java, .NET to FastAPI, Vue 3, PostgreSQL. Free code audit."
url: https://www.budgetapp.works/en/services/legacy-code-modernization
canonical_url: https://www.budgetapp.works/en/services/legacy-code-modernization
last_updated: 2026-10-12
---

[ Back to Services](/en/services)

⚡

# Legacy Code Modernization & Performance Rewrite

Rewrite slow, expensive legacy systems into high-performance modern stacks. Cut server costs, boost speed, and extend the life of your business-critical applications.

## Your Old Code Is Costing You Money

Legacy systems built on outdated frameworks — PHP 5, old Java, .NET Framework, monolithic Rails — consume too many servers, run too slowly, and cost a fortune to maintain. Every year you wait, the technical debt grows.

### What We Do

* **Performance Audit** — Profile your existing system to find bottlenecks: slow queries, N+1 problems, memory leaks, inefficient architecture
* **Incremental Rewrite** — Migrate module by module, not big-bang. Your business keeps running while we rebuild underneath
* **Modern Stack Migration** — Move to FastAPI, Vue 3, Supabase, or whatever fits your team. High performance, low infrastructure cost
* **Database Optimization** — Rewrite queries, add proper indexing, migrate from expensive licensed DBs (Oracle, MSSQL) to PostgreSQL
* **Infrastructure Right-Sizing** — Replace 10 overprovisioned VMs with 2 optimized containers on Proxmox. Same workload, 70% less cost
* **API Consolidation** — Replace scattered microservices and spaghetti integrations with a clean, documented REST API

### Real Results

* Laravel monolith → FastAPI + Vue 3: **5x faster response times**, server costs cut from HK$8,000/mo to HK$2,000/mo
* Legacy Java ERP → modern stack: **3 servers → 1 server**, 90% fewer support tickets
* WordPress + 12 plugins → Nuxt 3 SSR: **Page load from 4s → 0.8s**, SEO rankings jumped 40%

### Our Approach

We don't just rewrite — we **renew**. Your project gets a modern codebase, automated tests, CI/CD pipeline, and documentation so your team can maintain it going forward. No more vendor dependency.

[Get a Free Code Audit ](/en/contact)

---
Site map for agents: [llms.txt](https://www.budgetapp.works/llms.txt) · [sitemap.md](https://www.budgetapp.works/sitemap.md)