December 2025 Summaries

Fastly's KV Store is a versatile key-value storage solution that extends beyond basic CRUD operations, offering advanced features that enhance application development at the edge. With a globally distributed and durable architecture, it allows for fast edge-accessible storage that is eventually consistent. Key advanced features include metadata, which allows for smart data management by attaching up to 2048 bytes of UTF-8 string data to entries without requiring a schema; generation markers, which provide lightweight concurrency protection by using version control on data entries; insert-only writes, which ensure data is written once to avoid race conditions; and TTL (Time-To-Live), which automatically cleans up temporary data. These features enable sophisticated use cases such as CMS-like content management, configuration management with safe updates, A/B testing, preview deployments, and efficient static site serving. Fastly's KV Store's capabilities are already available for use in enhancing distributed systems, with examples like the Compute Static Publisher showcasing its potential.

Bots have become a significant part of internet traffic, with nearly one-third of all web activity now driven by them, according to Fastly's latest Threat Insights Report. The increasing influence of bots on business outcomes has led organizations to reassess their impact, as not all bot traffic is beneficial. While AI crawlers and headless bots pose operational threats, especially in the Financial and Commerce sectors, where they target transactions, they also have legitimate uses such as in testing frameworks and internal services. The rise of generative AI has altered traffic patterns, with certain industries like Commerce and the Public Sector experiencing concentrated bot activity for purposes like real-time data and content fetching. This shift necessitates a strategic approach to bot management that considers revenue, infrastructure costs, brand visibility, and innovation. Understanding bot behavior has evolved from a defensive measure to a crucial business decision, emphasizing the need for nuanced management to balance protection and operational efficiency.

The IDC InfoBrief, sponsored by Fastly, reveals that organizations with modern application security (AppSec) programs are significantly more likely to achieve superior business outcomes, including enhanced developer productivity, user experience, and application availability, while being nearly twice as likely to avoid data breaches. The study categorizes AppSec programs into four maturity levels—Emerging, Evolving, Established, and Exceptional—and highlights that programs in the Exceptional category demonstrate continuous, adaptive security measures deeply integrated into their software development practices. Nearly 1,000 global security and technology leaders participated, providing insights into essential practices and capabilities that define modern AppSec programs. The research emphasizes the importance of integrated security platforms and adaptive backlog management as key strategies for achieving exceptional results. The findings serve as a benchmark for organizations to assess and improve their AppSec maturity, offering actionable guidance to enhance their security posture and drive better business outcomes.

In 2025, Fastly's third-annual internship program stood out as a highlight of the year, earning the #1 spot in Vault's 2026 Internship Rankings for Best Internships in Software Engineering and Development. This recognition was based on positive intern feedback, emphasizing the program's role in nurturing emerging engineers and reinforcing Fastly's commitment to improving the internet. Interns such as Cami, Kyutza, Cindy, Rebecca, and others made significant contributions to various projects, ranging from developing tools for error monitoring and API services to enhancing web frameworks and security products. Each intern shared insights on their journey, highlighting the supportive and inclusive culture at Fastly that encouraged learning, collaboration, and personal growth. The program not only facilitated technical advancements but also fostered meaningful relationships and professional development, underlining Fastly's dedication to cultivating future engineering talent.

Fastly's On-Demand Migration for Object Storage provides a solution to the challenges of moving large datasets between cloud storage providers by enabling a flexible, cost-efficient approach that avoids the high costs associated with bulk data transfers. Instead of transferring all data at once, this service allows migration to occur upon the first request for an object, using a stateless, URL-driven method to transfer only the actively accessed files, significantly reducing egress fees and storage costs. This approach was successfully implemented by a leading streaming platform to "lazy load" images and manage new user uploads without incurring the expense and delay of a complete library migration, while also leveraging Fastly Bot Management to prevent unnecessary migrations. The service's versatility extends to migrations from any publicly accessible source, offering businesses an innovative way to manage their digital assets efficiently.

Fastly's "Pillars of Resilience" series emphasizes the critical role of human operators in maintaining and enhancing the resilience of their global network, despite advanced automation and self-healing systems. While automation efficiently manages routine failures, human operators are indispensable in addressing unexpected and complex issues that automation cannot foresee. These operators utilize abstract reasoning and situational judgment to make high-stakes decisions and view the system holistically, connecting disparate events to understand the broader context. Fastly values a blameless post-mortem culture for continual learning and system improvement, recognizing that resilience involves not just recovering from disruptions but also improving as a result. To empower their engineers, Fastly integrates AI tools that aid in decision-making and streamline incident analysis, thus allowing human operators to focus on critical and novel challenges. This approach underscores the belief that true resilience is achieved by combining automated processes with human ingenuity and expertise.

As peak season approaches, ensuring your website's readiness for increased traffic and demand is crucial, and implementing key strategies can enhance performance, security, and scalability. Techniques such as instant load, through caching, improve user experience by reducing latency, while shielding defends against traffic spikes, ensuring stability and lower costs. Total resilience is achieved by configuring multiple origins to prevent downtime, and rate limiting protects resources without impacting legitimate users. Dynamic lists allow real-time configuration changes, which are particularly useful for events demanding immediate adaptability, and optimization ensures efficient delivery of content tailored to user devices. Fastly's platform supports these strategies, promising speed, resilience, and security, crucial for maintaining a competitive edge and providing a memorable user experience during crucial periods.

Optimizing web infrastructure with Fastly's Content Delivery Network (CDN) offers a significant competitive advantage by enhancing user experience and reducing costs. Fastly enables businesses to measure performance using key metrics such as Origin Offload, which indicates the percentage of traffic handled by the CDN instead of the origin, and Cache Hit Ratio, which measures the percentage of requests resolved from cache. It facilitates serving dynamic content, like user profiles and real-time comments, through dynamic purging, which reduces origin load and improves delivery speed. By focusing on high-impact requests that are frequent, large, or critical to user experience, companies can achieve substantial cost savings, such as those from an e-commerce API with large responses. Fastly's suite of observability and control tools offers real-time visibility and strategic adjustments through features like purge scheduling and global configuration deployments, ensuring infrastructure optimization and security. Gabriela Luna and Guillermo Guardián highlight these strategies in a Spanish webinar, emphasizing that maximizing CDN efficiency is a crucial business strategy.

Recent vulnerabilities in React and Next.js, known collectively as React2Shell, have drawn significant attention due to their potential to facilitate remote code execution (RCE) attacks, presenting a serious threat to sensitive data. Following the announcement of React2Shell CVEs, two additional vulnerabilities—CVE-2025-55183 and CVE-2025-55184—were identified, affecting React Server Components by exposing source code and enabling denial of service (DoS) attacks, respectively. These vulnerabilities emphasize the necessity for organizations to promptly assess their systems for exposure and update to patched versions of the affected frameworks. Fastly, while not directly impacted, recommends using its Next-Gen WAF and Bot Management solutions for virtual patching and protection as organizations work to implement necessary updates. It is crucial for companies to adopt modern infrastructure practices, such as autoscaling, to mitigate the impact of potential DoS attacks and to remain vigilant against ongoing exploit attempts.

Modern software systems are exceptionally complex, often beyond the full comprehension of any single individual or team, which results in unknown unknowns, brittle dependencies, and constant firefighting. Fastly's API Discovery tool aims to address these challenges by providing automatic, continuous mapping of API traffic and changes, enhancing visibility and enabling proactive planning. This system helps transition teams from a reactive mode to strategic work by offering new features like Tree View and Inventory for better context and auditability. As engineers face distractions and constant interruptions, tools like API Discovery can provide real-time understanding and monitoring to foster API resilience. The development of these tools is driven by the need to embrace chaos, shifting the focus from merely fixing issues to understanding the reasons behind system failures and ensuring systems are designed to handle inevitable disruptions. Fastly's API Discovery offers an easy-to-use solution to gain instant visibility, reduce noise, and enhance API security, with future capabilities aimed at defining API standards and monitoring behaviors to prevent issues before they arise.

Fastly's global network has effectively mitigated trillions of DDoS attacks at layers 3 and 4, but the emergence of more sophisticated layer 7 attacks poses a significant threat to internet-facing applications and APIs. Despite a decline in overall DDoS attack volume for the fourth consecutive month, Fastly's data highlights that attackers are shifting focus from performance impacts to operational cost increases, targeting well-known enterprises especially during Cyber 5, a critical shopping period. Fastly's Adaptive Threat Engine, updated to enhance mitigation speed and accuracy, has contributed to fewer false positives and a more effective response to short-lived attacks. While attack volume on commerce customers remained relatively steady throughout November, security teams must maintain constant vigilance beyond the peak shopping days traditionally associated with high risk. Fastly's DDoS Protection, designed to automatically mitigate multi-vector attacks, proves crucial in adapting to evolving threats, suggesting that preparedness extends beyond expected high-traffic periods to ensure robust defense against financial implications of DDoS tactics.

Domain Inspector has been expanded to include support for Compute services, providing enhanced domain-level observability for edge applications alongside its existing Delivery services capabilities. This development allows users to access real-time, actionable metrics for troubleshooting and optimizing domain performance without the need for additional data collection complexity. Users can instantly access domain statistics through the Fastly UI or API, facilitating faster diagnosis and resolution of domain-specific delivery issues. The update offers total traffic visibility and granular, real-time details on requests and responses for fully qualified domain names (FQDNs), essential for managing changes in traffic behavior and ensuring service performance during significant events. Data is available in one-second intervals and retained for 45 days, accessible through custom dashboards or as a JSON-formatted stream. This enhancement brings Compute users the same level of observability as Delivery customers, enabling performance monitoring and optimization across multiple domains without custom logging solutions. Domain Inspector also integrates seamlessly with Cloud Optimizer and Media Shield, offering domain-level data across single or multiple CDNs directly in the Fastly UI. Users can start using Domain Inspector by contacting their account manager or Fastly support for assistance.

Black Friday, traditionally known for its intense single-day shopping surge, has evolved into a more prolonged and distributed period of consumer activity, particularly during the Cyber 5 window, which spans from Thanksgiving to Cyber Monday. Data from Fastly's Commerce customer base suggests that while Black Friday still marks a peak in traffic, it no longer stands out dramatically against the rest of November, which now sees a steady, elevated demand throughout the month. This shift in consumer behavior, characterized by a more sustained shopping pattern and the potential rise of agentic commerce driven by AI, necessitates changes in how retailers and their engineering teams prepare for peak seasons. Instead of focusing on a short-term spike, retailers need to plan for a continuous load, emphasizing robust infrastructure, real-time visibility, and security solutions. Fastly supports this by providing tools for observability, performance consistency, and security, helping retailers adapt to the extended high-demand period and ensuring a seamless shopping experience. Overall, the holiday shopping season has transitioned from a singular event to a more extended period, requiring strategic adjustments in operations and technology to meet evolving consumer expectations.

React2Shell is a critical vulnerability impacting enterprises worldwide, with cybercriminals exploiting it to gain arbitrary control over vulnerable application servers, leading to potential data breaches, cryptomining, and revenue disruption. Fastly reports that the vulnerability is easily weaponized, allowing attackers to automate and scale their attacks using public proof of concepts. It affects a wide range of industries and geographic regions, with attackers leveraging different strategies based on perceived security measures in place across regions. Fastly advises organizations to prioritize identifying and patching vulnerable React and Next.js applications to mitigate the risk, while also employing proactive security measures such as their NGWAF and Bot Management products. Despite these defenses, organizations should remain vigilant as attackers continue to evolve their techniques and target platforms, often with lucrative data, to maximize the return on their malicious activities.

Fastly has released a Beta version of its official C++ SDK for Fastly Compute, aimed at developers building performance-critical applications by leveraging the speed and control of C++ alongside Fastly's global network and WebAssembly (Wasm) runtime. This SDK enables developers to execute highly optimized C++ code at the edge, offering new capabilities such as executing core business logic at the speed of the Fastly network and utilizing familiar C++ bindings to edge services like KV Stores and Config Stores. The C++ SDK supports a polyglot architecture, allowing integration with languages like Rust and JavaScript, which promotes efficiency and reduces operational costs. It also enhances security with Wasm's memory-safety features and provides asynchronous handling for network operations, making it suitable for use cases in gaming, IoT, and interactive media. Fastly's Wasm runtime offers fast cold-start times, providing a significant architectural advantage for developers seeking to optimize edge computing applications.

Fastly's approach to building a resilient and high-performing global network focuses on two key principles: infrastructure diversity and soft influence. Infrastructure diversity involves using varied hardware, software, and network configurations across Fastly's Points of Presence (PoPs) to mitigate risks associated with uniformity and prevent widespread outages, thereby enhancing system resilience. This diversity allows Fastly to reroute traffic if a PoP is affected, ensuring continuous availability. Soft influence leverages real-time observability data to subtly guide network traffic, optimizing performance by directing users to the best-performing caches and ensuring minimal latency and high reliability. This method allows Fastly to dynamically adapt to changing network conditions, improving user experience and maintaining service continuity. Through these principles, Fastly demonstrates a commitment to performance, reliability, and resilience, ensuring that content is delivered rapidly and consistently, even amidst the dynamic challenges of the internet.

Retailers are facing challenges with CAPTCHAs during the end-of-year shopping season, as these security measures are causing significant friction for online shoppers, particularly heavy AI users. A survey of 881 U.S. online shoppers revealed that approximately 23% abandon their carts when encountering a CAPTCHA during checkout, with heavy AI users being slightly more likely to do so. Despite their intent to enhance security, CAPTCHAs offer diminishing protection against modern automation, as AI-powered bots can bypass these challenges more efficiently than humans. The study also highlights that heavy AI users are less patient with slow sites, associating site speed with trustworthiness, and are more likely to feel frustrated or distrustful when encountering CAPTCHAs. Retailers are encouraged to adopt adaptive, invisible security measures like Dynamic Challenges, which can verify legitimate users without interrupting their shopping experience, thereby reducing friction and maintaining conversions. As AI adoption becomes more widespread, the expectations of heavy AI users are anticipated to set new standards for online shopping experiences.

Fastly has been actively monitoring attempts to exploit the newly disclosed React2Shell vulnerabilities, CVE-2025-55182 and CVE-2025-66478, which affect applications using React 19 with React Server Components. After a proof of concept was publicly released, signals of exploitation attempts spiked, prompting Fastly to recommend immediate updates to React and Next.js applications. To mitigate risks, Fastly has released a Virtual Patch for its Next-Gen WAF to protect vulnerable systems while they await updates. The React2Shell vulnerability, a prototype pollution bug, allows attackers to execute arbitrary JavaScript code on affected servers with minimal effort, making it critical for organizations to apply protective measures quickly. Fastly's proactive collaboration with Vercel and other technology partners aims to provide cross-industry protection and minimize the impact of potential attacks. Fastly continues to monitor its global network and update customers on the evolving situation, emphasizing the importance of internet-wide resilience and collaboration among cloud providers.