# Compile what you open. Keep what you need.

A project may have hundreds of routes while you are working on just one. PRNext 0.1.17 uses that difference to spend less time on unopened routes and reuse work whose inputs have not changed.

The useful question is not whether a cache can return a file quickly. It is whether that file still represents the current application. The development pipeline keeps dependency tracking, generation identity and conservative fallback paths around every shortcut.

## Start with the routes you actually open

Requested-route compilation includes the route needed by the browser along with its shared layout, error and dependency infrastructure. Open tabs keep their routes active; a bounded inactive set avoids retaining the entire project indefinitely.

Middleware, rewrites and parallel or intercepting routes can make the dependency graph less predictable. In those cases PRNext keeps complete compilation instead of guessing which route is safe to skip.

For example, changing a shared header should refresh the open pages that import it, while an unrelated tab keeps its current model. A browser counter and a document marker provide a stronger check than a request returning 200: they show whether the update preserved the interaction already in progress.

## Reuse transformations across restarts

Development transformations are stored separately from production build inputs. Reusing a transform requires the relevant source and policy to match; an optimization cannot rely only on a filename having stayed the same.

A persistent cache is optional work-saving infrastructure. An unavailable or invalid entry falls back to compilation. It is not a cache of your dynamic application responses.

Development and production have different lifecycles, so their reusable work is kept separate. A restart can reuse a valid transform without reusing a running application process or an authenticated response. Changes to configuration or compilation policy must still invalidate the work they affect.

## Treat a stylesheet edit as a stylesheet edit

When a supported edit only changes CSS, PRNext publishes immutable stylesheet assets without rebuilding the JavaScript graph or restarting the application worker. The browser can retain its document and React state.

A change to CSS Module exports can affect JavaScript imports. Sass and custom processors can have wider dependencies too. These cases fall back to the complete compiler rather than publishing an incomplete update.

Immutable generations also give an edit a distinct asset identity. A tab already using the preceding generation can finish loading its files instead of seeing their contents change underneath the request. The optimization reduces work while keeping the relationship between a build and its assets explicit.

## Keep a straightforward fallback

The safe development mode investigates incremental-build issues by compiling the complete route graph with fresh compilers. It disables persistent transform reuse and does not prewarm workers, while keeping compatible Fast Refresh behavior.

Use it to compare the same edit with a simpler compilation path. A problem that disappears in safe mode gives you a focused reproduction to report; it does not by itself identify the faulty optimization. Keep the source change, the affected routes and the build diagnostics with that report.

Published: 2026-10-24

Modified: 2026-10-25

Author: PRNext

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Language: en

Canonical: https://prnext.dev/blog/how-prnext-keeps-development-work-focused

Index: https://prnext.dev/llms.txt