Redirects

3/10/2026

This post demonstrates how Vercel's CDN and Edge Config can be used to proxy external applications, providing security and observability features. It introduces the concept of an 'inner host' (origin server) and 'outer host' (Vercel project domain) for proxying. A `vercel.ts` configuration is provided to rewrite traffic to the inner domain with a security header. Additionally, it details the use of microfrontends (`microfrontends.json`) to integrate separate Vercel projects (e.g., Next.js apps) onto specific routes of the proxied domain, allowing for incremental modernization and feature additions without a full migration. This extends the capability of dynamic routing and proxying beyond simple redirects to full application proxying and hybrid architectures.

3/3/2026

Introduced sharding of redirect data into smaller files, combined with Bloom filters for fast negative lookups. Implemented binary search over sorted keys within each shard to perform logarithmic-time lookups for individual redirects, avoiding full shard JSON parsing and improving performance under high CPU load.

11/24/2025

The post details a redesign of the Vercel Firewall user interface to improve usability and provide better visibility into security events. Key improvements include a redesigned overview page with alerts, rules, events, and denied IPs feeds; a new traffic page with comprehensive intelligence on IPs, JA4 digests, AS names, user agents, request paths, and rules with most activity; dedicated tabs for Firewall Rules and Audit Log; and faster event inspection with a detailed view directly within the page. While the post focuses on UI/UX improvements for security tooling, it implies underlying system enhancements to provide this richer data and faster inspection, potentially related to how traffic data is processed and presented. However, it does not introduce new core system capabilities like sharding or Bloom filters for redirects, but rather enhances the user's interaction with existing security systems.

9/19/2025

This post details the optimization of the path lookup operation by replacing slow JSON parsing with Bloom filters, reducing memory usage by 15% and improving TTFB by 10% for websites with many static paths. The new implementation uses Base64 encoded Bloom filters for faster uploads and parsing, achieving near-zero latency for path lookups.

9/15/2025

This post details Helly Hansen's migration to Next.js and Vercel, focusing on performance improvements and Black Friday growth. Key technical aspects include an incremental migration strategy, starting with checkout pages, and leveraging Vercel's CDN and Functions for scalability. The shift from client-side to server-side rendering on Vercel's Edge Network significantly improved Core Web Vitals, reducing load times and Cumulative Layout Shift. For peak traffic events like Black Friday, Vercel Data Cache and Incremental Static Regeneration (ISR) were utilized for performance and stability. The post also highlights the use of feature flags for increased testing velocity and personalization.

1/30/2025

This post details optimizations to Vercel's Incremental Static Regeneration (ISR) implementation. Key improvements include regionalized caching, where ISR cache entries are now stored in the same region as the associated functions, leading to lower latency for cache retrieval and faster revalidations. Additionally, automatic compression has been enabled for ISR cache entries, reducing write and read units, as well as Fast Origin Transfer (FOT) costs, resulting in up to 65% savings on ISR reads and writes. These improvements are automatically applied to existing deployments.

9/17/2024

This post details how Mecum Auctions, with the help of Americaneagle.com, leveraged Vercel's Frontend Cloud and Incremental Static Regeneration (ISR) to manage a large-scale digital presence. Specifically, it highlights the use of ISR for on-demand generation and caching of 275,000 lot pages, which significantly improves performance and reduces server load compared to pre-generating all pages. The architecture integrates Salesforce as a data source, pushing data to WordPress (CMS) and Algolia (search), with Vercel serving the pages and implementing ISR. This strategy allows for efficient content updates and faster digital experiences for users.

9/16/2024

This post introduces Incremental Static Regeneration (ISR) as a caching strategy that combines static site generation (SSG) and server-side rendering (SSR) to deliver dynamic content at cached speeds. It details the benefits of ISR, including cached speeds with live content, selective regeneration, on-demand invalidation, and guaranteed cache durability. The post explains how ISR fits into Vercel's caching stack, alongside static assets, application-level caching, and client-side caching. It highlights framework adoption for ISR (Next.js, SvelteKit, Nuxt, Astro, Gatsby, Remix) and provides real-world scenarios in e-commerce, news websites, and AI-powered applications. The post also details implementation methods for ISR, including time-based regeneration with a SvelteKit example and on-demand regeneration with an Astro example using a bypass token and `x-prerender-revalidate` header.

6/3/2024

This post details how Mintlify utilizes Vercel's platform, specifically Next.js and its domain management capabilities, to support a multi-tenant documentation platform with thousands of custom domains. It highlights Vercel's ability to programmatically assign custom domains, subdomains, and SSL certificates, enabling Mintlify to scale without managing infrastructure. The post emphasizes the scalability of serving terabytes of documentation on a single Vercel project, the performance benefits of Next.js and Vercel's edge network, and the automation of custom domain setup and SSL issuance via Vercel's API. It also mentions the use of Incremental Static Regeneration (ISR) for instant documentation updates.

8/30/2023

This post details incremental migration strategies, contrasting 'big bang' with 'incremental' approaches (vertical and horizontal). It highlights the trade-offs, particularly the interop effort versus risk reduction. For frontend migrations, it emphasizes the use of reverse proxies and Vercel's Edge Middleware for phased traffic migration. It also touches upon migrating from monolithic to composable architectures and the specific techniques for migrating web frontends using reverse proxies and gradual traffic shifting.

8/9/2023

Algolia reduced build times by 50% by migrating to Next.js on Vercel, leveraging Incremental Static Regeneration (ISR) and Vercel Analytics. This improved their development cycle and enabled faster website changes.

4/14/2023

This post details how Gearbox uses Edge Middleware to incrementally adopt Next.js, managing blog redirects to maintain SEO by rewriting new posts to an existing WordPress blog under the hood, filtering traffic, and pointing to other services and websites while masking the URL and without complicated server setup. This allows for incremental migration in phases and management of scopes.

4/7/2023

This post details how mmm.page migrated from an SPA on Amazon S3 to Vercel, leveraging Server-Side Rendering (SSR) for improved SEO and custom domain management. It highlights Vercel's ability to handle scale, monetize offerings, and innovate. The post also mentions Vercel's caching capabilities, which reduce database calls and improve performance for dynamic data. While the post doesn't introduce a new technical capability, it demonstrates the practical application and benefits of existing Vercel features like SSR and caching in a customer scenario.

3/30/2023

This post introduces the use of Vercel's Edge Network, specifically Edge Config and Routing Middleware, to implement high-performance A/B testing and personalization strategies as a replacement for Google Optimize. It details how Edge Config provides sub-millisecond configuration read times and how Routing Middleware can serve correct page variants instantly to eliminate Cumulative Layout Shift (CLS). It also provides an example of tracking experiment results using a `saveData` function.

12/15/2022

Introduced Vercel Edge Config, a globally distributed, ultra-low latency data store for configuration data. It enables near-instant reads (5ms or less for most lookups) by pushing data to every Vercel region. Key use cases include A/B testing, feature flags, dynamic redirects, and request blocking rules. Announced integrations with Statsig and HappyKit for feature flagging and A/B testing at the edge. Provided an Edge Config SDK and examples for integration.

11/23/2022

Introduced Edge Config, a globally distributed, ultra-low latency data store for configuration data. It enables near-instant reads of configuration data from Edge Middleware, Edge Functions, and Serverless Functions. Optimized for fast, inexpensive reads and infrequent writes, with data replicated to all regions before request. Supports A/B testing, feature flags, dynamic redirects, and request blocking rules. Provides an API for querying data and integrates with Statsig and HappyKit.

9/9/2022

This post details the implementation of A/B testing for Vercel's Templates page using Next.js Edge Middleware. It explains how Edge Middleware can be used to perform rewrites at the edge to serve different variants of a page to different users, thereby avoiding client-side layout shifts. The post also covers the use of catch-all routes and on-demand revalidation for dynamic page generation and how to conditionally render skeleton loaders to further improve user experience during data fetching.

4/26/2022

This post introduces on-demand Incremental Static Regeneration (ISR) for Next.js, allowing for selective cache invalidation of specific pages via an API call. It details how HashiCorp uses ISR for managing documentation content at scale, deferring generation of less-visited pages and propagating content changes without full rebuilds. The integration with GitHub Actions and Vercel deploy hooks for triggering on-demand ISR based on file changes is also discussed.

1/26/2021

This post introduces Next.js Redirects, a feature introduced in version 9.5, allowing rerouting of incoming request paths to other destinations. It details configuration via `next.config.js` with support for path matching, regex path matching, and wildcard paths, providing a code example for permanent redirects.

10/29/2019

Introduces the concept and implementation of redirects, including how to define source and destination URLs, and the HTTP status codes associated with different redirect types (e.g., 301, 302).