---
title: Legacy App Modernization Without a Feature Freeze @ Varstatt
url: https://varstatt.com/x/founders/app-modernization
description: "Legacy app modernization for founders: I rebuild V1 as V2 while it keeps running, one feature at a time. No feature freeze, no big-bang cutover. $997/week."
section: Services (https://varstatt.com)
---
# Legacy App Modernization

V2 built beside your live V1, one feature at a time, until every user has moved. $997/week.

**What's included:**

- ✅ Senior developer
- ✅ Full code ownership
- ✅ Continuous progress
- ✅ Stop anytime
- ❌ Meetings overhead
- ❌ Scope creep
- ❌ Agency markup
- ❌ Billing surprises

**Get started:**

- [Start a Project](https://varstatt.com/start?cta=agent)
- [Ask Jurij](mailto:jurij@varstatt.com)

## Portfolio

- **Redesign & V2 development of SOAPNoteAI, an AI charting assistant for busy clinicians** — [soapnoteai.com](https://soapnoteai.com)
- **Initial launch of TenderPilot, an AI-powered tendering software for Australian SMEs** — [tenderpilot.ai](https://tenderpilot.ai)
- **Content Pal, a pay-per-use social media content scheduler for solo creators** — [contentpal.app](https://contentpal.app)
- **Fidder, a free & simple RSS reader that cuts through the noise and works everywhere** — [fidder.app](https://fidder.app)

## Rewrites Fail at the Freeze

| | Big-Bang Rewrite | **V2 Beside V1** |
|---|---|---|
| New Features | Frozen until the new app launches | Ship in V2 throughout, starting with what V1 can't host |
| V1 | Switched off on launch day | Live and earning until the last user moves |
| Cutover | Everyone at once, and it partly works | In batches, each user on their next sign-in |
| If Something Breaks | Nothing to fall back to | One-click fallback to V1 on every screen |
| Main Cost | Months with nothing shipped | Each change must work in V1, V2 and the shared backend |

## Every Week, V2 Does More

- [x] Shared sign-in and one backend, the bridge

- [ ] The first feature V1 can't host

- [ ] Account page, hidden until ready

- [ ] Old screens, in your order

- [ ] Move users, batch by batch

- [ ] Remove the code linking V1 and V2

## The Last Rebuild, Start to Finish

- **5 days** From the first call to the first commit

- **8 months** V1 and V2 side by side, no freeze

- **2 months** From matching V1 to moving users, spent on stability

- **100%** Of users on V2, each on their next sign-in

[Read the full case](https://varstatt.com/jurij/p/soapnoteai-v2-now-serves-100-percent-of-users)

## Who It's For

**Right For**

- A V1 that can't host what's next, like an AI assistant

- An inherited codebase whose developer has left

- An AI-built V1 that needs a structure to grow in

**Better Elsewhere**

- Million-line systems with five teams *A bigger firm*

- An app that's down or leaking today *Fix it first, then rebuild*

- A V2 far from JavaScript and TypeScript *A developer of that stack*

## How It Works

A simple, predictable and transparent process that eliminates development headaches.

1. **Subscribe** — After subscribing, you get a dedicated task board. It becomes your migration roadmap.
2. **Setup** — Week one: I read V1, map what depends on what and agree the migration order.
3. **Plan & Develop** — You set the priorities. I build the bridge, then V2 one task at a time.
4. **Review & Refine** — You review each piece on the real app. I revise until you're satisfied.
5. **Progress** — You approve finished work. Once V2 has everything, the work turns to stability.
6. **Maintain** — Users move and the code linking V1 and V2 comes out. You report issues anytime; I handle them first.

## Pricing — Retainer

One weekly price for the whole move. No re-scoping if V1 is bigger than it looked.

- **Price:** $997 / week
- **Plan:** A senior engineer building V2 while V1 keeps running.
- **Includes:**
  - 🧑‍💻 10+ years shipping software
  - 🗣️ Direct access to developer
  - 🗂️ Dedicated task board
  - 📦 1 task at a time, unlimited revisions
  - ⚡ Each task in ~72 hours on average
  - 🪪 Full code & assets ownership
  - 🩹 Bug fixes & ongoing maintenance
  - 🎁 Free week 0: onboarding and setup
  - 🛑 Pause or cancel anytime
- **CTA:** [Get Started](https://varstatt.com/start?cta=agent)
- **Questions:** jurij@varstatt.com

## FAQ

### What is legacy app modernization?

Moving a working app onto a stack you can keep building on. For a founder, often a V1 from two years ago, or an [AI-built app from six months ago](/jurij/p/it-works-isnt-enough-for-commercial).

### Should we rewrite or refactor?

Refactor if the stack can carry what's next: the code gets better [as it's touched](/principles/delivery/scout-rule). If it can't, rebuild beside V1.

### Can V1 stay live during the rebuild?

Yes. V1 stays live for the whole move, with no maintenance window.

### Can you work without V1's developer?

Yes. V1 is the spec while it runs: when nobody remembers a behaviour, I check it there. V2 ships [documented](/principles/diligence/documentation).

### Which stacks can you take on?

V1 can be static HTML, older React or Node.js. V2 lands on the [default stack](/principles/delivery/default-stack), or keeps your backend serving every client. Far from JavaScript, I say so in my first reply.

### How long, and what does it cost?

$997/week, [pause or cancel](/principles/partnership/exit-freedom) anytime. The length follows how much V1 does.

### Can I start with the plan alone?

Yes: one week. I read V1 and hand you the migration order and the rewrite-or-refactor answer. Keep going, or take the plan anywhere.

### What if V2 isn't right?

I revise until you're satisfied. V1 keeps running and the code is [yours from day one](/principles/philosophy/client-owns-everything), so stopping never leaves you without a product.

### How do I get started?

Fill in the [project form](/start?cta=app-modernization-faq), about a minute. I reply the next working day; if it fits, with a first plan and a call invite.

## Testimonials

> "Jurij understand the core problem, insists on building the right experiences for the customers."
> — [Kunal Modi, Founder @ SOAPNoteAI](https://www.linkedin.com/in/jurijtokarski/details/recommendations/)

> "Working with Jurij is an absolute joy, consistently exceeds expectations."
> — [Janis Ozolins, Content Creator](https://x.com/OzolinsJanis/status/1875168034249146609)

> "Consistently delivered quality code in great time, very hard working & precise."
> — [Bartosz Poźniak, CEO @ MyCointainer](https://www.linkedin.com/in/jurijtokarski/details/recommendations/)

> "The kind of engineer that every company on the planet would be lucky to have."
> — [Hosam Mazawi, COO @ LemonUnit](https://www.linkedin.com/in/jurijtokarski/details/recommendations/)

## [Founders × Varstatt](https://varstatt.com/x/founders)

App Modernization fits founders best: people building a product without a technical co-founder.

- **[Fractional CTO](https://varstatt.com/x/founders/fractional-cto)** "No one makes the technical calls." The calls and the code, every week.

- **[Prototype](https://varstatt.com/x/founders/prototype-development)** "An idea nobody has clicked." The core flow on a live link in one week, one payment.

- **[MVP Development](https://varstatt.com/x/founders/mvp-development)** "An idea, ready to test with paying users." The smallest real product, launched in week 6.

- **[SaaS Development](https://varstatt.com/x/founders/saas-development)** "Ready to build the whole product." Launched in week 6, then built on real feedback.

- **[PWA Development](https://varstatt.com/x/founders/pwa-development)** "Phones, without three separate apps." One app that installs from a link.

- **[Vibe Coding Rescue](https://varstatt.com/x/founders/project-rescue)** "An app stuck, unsafe, or left by its developer." The bleeding stopped and a plan, in one paid week.

- **App Modernization (this page)** "A V1 that holds the product back." V2 built beside it, until every user moves.

- **[Tech Due Diligence](https://varstatt.com/x/founders/tech-due-diligence)** "A raise or a purchase on the calendar." What diligence will find, ranked, in one paid week.

Not a founder? [See what Varstatt offers you](https://varstatt.com/x).

## About

Varstatt is run by [Jurij Tokarski](https://varstatt.com/jurij), product engineer since 2011.

Contact: [jurij@varstatt.com](mailto:jurij@varstatt.com) / [X](https://x.com/jurijtokarski) / [LinkedIn](https://www.linkedin.com/in/jurijtokarski/)

Sole proprietorship headquartered in Rzeszów, Poland. VAT ID: PL8133854722.