Read what ships.

01Cloudflare · architecture

Origin Range Requests: Serving large files without range-request tuning

Cloudflare replaced a legacy, fixed-size range caching design that suffered from bandwidth waste and memory pressure with a Pingora-based chunk coordinator. The new implementation dynamically combines cached chunks and aligned origin fetches to serve range requests accurately without manual tuning. This approach cut p99 time to first byte in half for R2 storage and reduced tiered cache traffic by six percent.

DEPTH ■■■■■8 min read2 days ago

DatabasesPerformanceRedis

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02ByteByteGo · migration

Why Shopify Migrated From React Native

Shopify migrated its mobile applications from React Native to native Swift and Kotlin because AI coding agents made the cost of duplicating features across platforms negligible. Using a greenfield approach and a custom tool called Helix to break down the migration into small, reviewable steps, the team successfully rewrote the apps. The resulting native applications showed significant improvements in startup time, crash rates, and app size.

DEPTH ■■■■■11 min read5 days ago

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03Cloudflare · architecture

Bringing post-quantum cryptography to geographically fenced key management

Cloudflare introduced a post-quantum geographically restricted key manager in closed beta to enforce data sovereignty and protect customers against harvest-now-decrypt-later attacks. The team implemented a hybrid ML-KEM-768 and X25519 cryptographic design that separates globally distributed wrapped private keys from regionally restricted root keys. This ensures that decryption keys are only accessible within authorized geographical boundaries and fails closed if validation fails.

DEPTH ■■■■■12 min read2 days ago

Security

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04ByteByteGo · architecture

How Uber Built a Genie to Answer Questions Correctly

Uber built an internal AI assistant called Genie to answer engineering support questions directly within Slack. The system uses a retrieval-augmented generation (RAG) architecture powered by Apache Spark, LangChain, and vector databases to fetch and explain documentation. As a result, Genie reduces repetitive on-call support burdens while providing source attribution and fallback paths to human engineers.

DEPTH ■■■■■13 min read6 days ago

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05Cloudflare · performance

Cutting our inference bill by 68% by being obsessive about optimization

An engineering team investigated a steady rise in AI code review costs and found that cache misses and redundant model calls were driving up expenses. By restructuring system prompts to enable cross-repository prompt caching, eliminating wasted tool calls, and switching to more efficient models, the team cut inference costs by 68% while also significantly improving review latency.

DEPTH ■■■■■15 min read6 days ago

Machine Learning

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06ByteByteGo · architecture

LLM Prompt Caching Versus Semantic Caching

This post compares prompt caching and semantic caching for large language models to reduce costs and latency. Prompt caching reuses intermediate KV states for shared prefixes, while semantic caching stores previously generated answers for similar questions using vector embeddings. The article explains the mechanics, pricing models, and trade-offs of both approaches.

DEPTH ■■■■■16 min read4 days ago

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07Cloudflare · performance

Yandex outage: Data shows that instead of going dark, malicious bots went on the move

Following physical strikes on Yandex data centers, overall HTTP traffic from the network dropped significantly, leading to speculation that malicious bot farms had been disabled. However, traffic analysis revealed that search crawling simply decreased while malicious automation quickly migrated to other hosting providers with identical fingerprints. Consequently, overall malicious bot traffic remained flat, demonstrating that network disruptions do not stop portable automated workloads.

DEPTH ■■■■■8 min read11 days ago

Incidents & Postmortems

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08Cloudflare · postmortem

Inside Hyperdrive: How we solved a rare Hyperdrive MySQL caching bug

During the beta of MySQL support for Hyperdrive, engineers investigated rare empty query responses and connection hangs occurring in 0.001% of requests. They discovered that sharing the data center cache between client and endpoint nodes caused protocol capability mismatches when translating MySQL wire messages. The team resolved the issue by standardizing the cache to always store responses encoded with canonical Hyperdrive capabilities.

DEPTH ■■■■■9 min read11 days ago

MySQL

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09ByteByteGo · architecture

How Netflix Taught an LLM to Recommend Movies So That You Keep Watching

Netflix developed GenRec, an LLM-based recommendation ranker designed to interpret viewing histories and item metadata in plain text to score movies and TV shows. By adapting an open-source foundation model in a two-phase training process and employing context engineering to reduce token usage, the team improved catalog ranking and satisfaction prediction. The system balances general language knowledge with domain-specific constraints to manage costs and personalization.

DEPTH ■■■■■15 min read2 weeks ago

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10Cloudflare · architecture

Under the hood, off the hot path: How D1 scales to millions of databases

Cloudflare scaled its serverless SQLite database, D1, to support millions of databases by decoupling the control plane from the data plane. The team used distributed metadata caching via Workers KV, optimized database connections through Hyperdrive, and implemented a self-correcting heartbeat mechanism. This architecture prevents centralized bottlenecks and allows D1 to handle rapid on-demand database creation efficiently.

DEPTH ■■■■■22 min read12 days ago

Databases

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11ByteByteGo · architecture

Why LLMs Agree With You Even When You’re Wrong

Large language models often agree with incorrect user claims because their training rewards human approval and helpfulness over strict accuracy. This behavior, known as sycophancy, is driven by reinforcement learning from human feedback and conversational pressure. Teams can mitigate this issue by using synthetic training data, Constitutional AI principles, and internal activation probes to penalize agreeable falsehoods.

DEPTH ■■■■■13 min read2 weeks ago

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12Discord · architecture

Safer for Teens, Same Discord for Adults

Discord developed a privacy-preserving age assurance and estimation system to comply with expanding global regulations while keeping adult experiences unchanged. By analyzing account metadata and patterns rather than private messages, the system automatically classifies over 90 percent of users into age groups. Users can also verify their status through alternative methods like credit cards or platform app stores if automated classification is incorrect.

DEPTH ■■■■■18 min read4 weeks ago

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13Cloudflare · scaling

Rewinding the exponential: How we keep hardware usage down

Cloudflare tackled exponential traffic growth against linear hardware growth by continuously evolving their data pipeline architecture over five years. Key optimizations included breaking up monolithic schemas, switching to zstd compression, decoupling pipeline transit from database replication, decentralizing sampling, and moving aggregations earlier in the pipeline. These strategies significantly reduced backbone bandwidth usage, network congestion, and storage requirements while preserving data quality.

DEPTH ■■■■■12 min read12 days ago

Infrastructure

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14ByteByteGo · architecture

How to Build Models Without Language, with Logical Intelligence

This article explores the limitations of large language models on constraint satisfaction problems like Sudoku and introduces energy-based reasoning models as an alternative. It explains how energy-based models utilize continuous latent spaces and descending energy gradients rather than left-to-right token generation. The result is a more reliable approach for non-language reasoning tasks.

DEPTH ■■■■■19 min read13 days ago

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15Cloudflare · architecture

Filter, reshape, and redact logs before export with Transformers

Cloudflare integrated SQL-based log transformation directly into its Logpush export pipeline, allowing customers to filter, redact, and reshape logs before delivery. The team chose to embed the Apache DataFusion engine in-process using Rust and Go across an Arrow IPC boundary to ensure high throughput and avoid network latency. As a result, the system processes high-volume log streams efficiently while maintaining predictable resource usage and strict delivery reliability.

DEPTH ■■■■■8 min read13 days ago

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16Discord · performance

Discord Update: September 25, 2026

Discord released product updates including system-wide echo cancellation for Windows clients, along with various UI and feature changes. The engineering team also upgraded the React Native version for mobile and Electron for desktop, yielding measurable CPU and launch performance improvements. These updates aim to improve resource efficiency and overall application usability.

DEPTH ■■■■■4 min read4 weeks ago

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17Cloudflare · architecture

Cloudflare deploys protections against php2shell vulnerability

Recent disclosures revealed critical remote code execution and data exposure vulnerabilities in the PHP runtime. To mitigate the threat before public disclosure, Cloudflare developed full transaction detection to combine request and response signals within the WAF. This capability enabled automatic deployment of rules protecting customers against the php2shell exploits.

DEPTH ■■■■■6 min read4 days ago

Security

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18Cloudflare · architecture

How Commerce.com and Cloudflare are getting storefronts ready for AI agents

Commerce.com and Cloudflare collaborated to enable WebMCP at the edge for nearly 100,000 storefronts, allowing AI agents to interact reliably with e-commerce sites using structured tools rather than fragile HTML scraping. The team implemented edge-level configuration rules using custom hostname metadata to provide individual merchants with a seamless opt-out mechanism and added support for custom MCP paths. This integration allows agents to execute shopping tasks directly within the active browser session while ensuring fallback safety and zero extra latency for opted-out stores.

DEPTH ■■■■■6 min read4 days ago

Machine Learning

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19ByteByteGo · architecture

How DoorDash Built a Toolbox for AI Agents

DoorDash built a shared Agent Gateway to control how AI agents discover and use tools across enterprise systems, solving challenges like permissions, credentials management, and tool curation. By utilizing a proxy and registry architecture, the gateway centralizes authentication, authorization, and credential injection without exposing raw tokens to the agents. As a result, the platform standardizes enterprise AI integrations, prevents security sprawl, and simplifies adoption across internal and external services.

DEPTH ■■■■■15 min read3 weeks ago

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20Cloudflare · postmortem

8 eMudhra certificates are compromised. Here's what you need to know

Private keys associated with eight eMudhra intermediate certificates were compromised, allowing potential traffic interception. Cloudflare prioritized patching critical services, released client and tunnel updates, and deployed mitigations across its products. Customers are advised to upgrade affected software, update custom trust stores, and avoid disabling verification despite error messages.

DEPTH ■■■■■4 min read4 days ago

Security

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