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Three Days in August: What a DDoS Attack Exposed in Our Network
In August 2026, a large DDoS attack hit a customer and our own network directly. What happened, where our defences fell short, and what changed since then.
8 min · 1,730 words
The new season of Survivor airs next week. My favorite thing about watching Survivor is arguing about the strategy of the show: who should have won the season? Is it better to play under the radar? Or does making big moves set you up to win? Who is the greatest player of all time: Cirie? Tony? Boston Rob? I thought it’d be fun to build a machine learning model to help answer these questions.
13 min · 3,012 words
Hello, HellGatesPostmortem of a year-unsolved gate-level crackme that GPT-6 cracked in minutes
xutaxkamay recounts designing HellGates—a VHDL custom CPU with obfuscation, anti-tamper, and anti-debug that stumped humans and LLMs for a year—until GPT-6 solved it in under half an hour, then walks through what actually broke.
25 min · 5,662 words
How we tracked down a 16-year-old SQLite bugOriginal article link with an AI-written directory summary
Alex Chan recounts the investigation of repeated Tailscale outages that exposed a long-standing SQLite bug. The case study explains the surrounding database architecture, forensic work, and the eventual understanding of the failure.
1 min · 78 wordsagent-written
Refactoring internal documentation in NotionOriginal article link with an AI-written directory summary
A concrete effort to repair internal documentation after a migration to Notion. Will Larson describes diagnosing stale pages, duplication, unclear ownership, and the practical work of making documentation trustworthy again.
1 min · 76 wordsagent-written
The Design & Implementation of SpritesOriginal article link with an AI-written directory summary
Thomas Ptacek explains the design of Sprites as disposable, stateful computers. The engineering account explores how Fly.io makes isolated execution environments quick to obtain while retaining useful system state.
1 min · 75 wordsagent-written
Finding and Fixing Ghostty's Largest Memory LeakOriginal article link with an AI-written directory summary
Mitchell Hashimoto traces a substantial memory leak in Ghostty to its terminal-content data structures. The account explains why particular workloads exposed the problem and how understanding the internals led to a fix.
1 min · 79 wordsagent-written
CorrosionOriginal article link with an AI-written directory summary
Thomas Ptacek and Peter Cai examine Corrosion, Fly.io's state-synchronization system. A serious outage motivates a detailed discussion of propagating routing information, distributed failure modes, and the tradeoffs in the system's design.
1 min · 79 wordsagent-written
How we built it: Real-time analytics for Stripe BillingOriginal article link with an AI-written directory summary
Reed Trevelyan explains the shift from delayed batch processing to fresher analytics for Stripe Billing. The article describes the architecture and processing changes required to reflect subscription activity while preserving historical accuracy.
1 min · 79 wordsagent-written
How we built it: Jurisdiction resolution for Stripe TaxOriginal article link with an AI-written directory summary
Erich Rentz and Danko Komlen explain how Stripe resolves taxing jurisdictions for transactions. The engineering account explores geographic boundaries, offline preparation, and fast online lookups in a complex and changing ruleset.
1 min · 80 wordsagent-written
Taming A Voracious Rust ProxyOriginal article link with an AI-written directory summary
Peter Cai investigates a CPU-hungry failure in Fly.io's Rust routing proxy. The incident account connects observability, production debugging, and the behavior of the service that routes requests across a global network.
1 min · 77 wordsagent-written
Making Machines MoveOriginal article link with an AI-written directory summary
Thomas Ptacek explains the work needed to move virtual machines with attached local storage between physical hosts. The account explores the operational cost of fast local NVMe storage and the migration machinery built to address it.
1 min · 82 wordsagent-written
How Stripe’s document databases supported 99.999% uptime with zero-downtime data migrationsOriginal article link with an AI-written directory summary
Jimmy Morzaria and Suraj Narkhede describe Stripe's MongoDB-based document infrastructure and its data movement platform. The case study focuses on moving data, balancing capacity, and changing database deployments while keeping services available.
1 min · 81 wordsagent-written
Test clocks: How we made it easier to test Stripe Billing integrationsOriginal article link with an AI-written directory summary
Ji Huang explains how simulated clocks make recurring billing behavior testable without waiting for real time to pass. The article examines time-related edge cases and the design of Stripe's billing test infrastructure.
1 min · 79 wordsagent-written
JIT WireGuardOriginal article link with an AI-written directory summary
Lillian Berry describes changes that make Fly.io's use of WireGuard more scalable. The account examines the networking model behind flyctl and the practical work of managing peers as usage grows.
1 min · 76 wordsagent-written
Ledger: Stripe’s system for tracking and validating money movementOriginal article link with an AI-written directory summary
Ilya Ganelin describes Ledger, Stripe's internal record of financial movements. The account explains how immutable records and data-quality checks help reconcile expected payment behavior with imperfect external systems.
1 min · 75 wordsagent-written
Surpassing 10Gb/s over TailscaleOriginal article link with an AI-written directory summary
Jordan Whited explains throughput improvements in Tailscale's userspace networking. The technical account explores UDP segmentation offload and checksum optimizations, with measurements showing how the changes affect Linux performance.
1 min · 74 wordsagent-written
Practical Problems with Auto-IncrementOriginal article link with an AI-written directory summary
Two concrete database behaviors motivate a closer look at auto-incrementing identifiers. Sam Rose demonstrates failure cases in MySQL and PostgreSQL and explains why he often prefers UUIDs for new applications.
1 min · 75 wordsagent-written
Making an SSH client the hard wayOriginal article link with an AI-written directory summary
Mihai Parparita explains the engineering behind a browser-based SSH client that joins a Tailscale network. The account covers bringing networking components and an SSH implementation into the browser with WebAssembly.
1 min · 76 wordsagent-written
How Stripe builds interactive docs with MarkdocOriginal article link with an AI-written directory summary
Ryan Paul explains how Stripe developed Markdoc for interactive, personalized documentation. The case study examines balancing useful page behavior with an authoring format that keeps content understandable and maintainable.
1 min · 76 wordsagent-written