Modernizing Reddit infra 💬, critical React bug 🚨, the ACME protocol 🔐

Reddit aims to deliver reliability and performance with a modern tech stack, which involves completely getting rid of its Python monoliths ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌  ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ ‌ 

Sign Up |Advertise|View Online TLDR Together With  TLDR Dev 2025-12-04 Clerk's Next.js setup now works directly in your AI assistant (Sponsor) If you use Cursor, Claude, or ChatGPT for coding, you can now add authentication without leaving your workflow. Our quickstart includes a pre-built prompt that guides your AI through the complete setup: SDK installation, middleware configuration, and component integration. Click to open the prompt directly in your assistant, or copy it manually. Either way, you get working authentication without switching between docs and your editor. 🧑‍💻 Articles & Tutorials Modernizing Reddit's Comment Backend Infrastructure (7 minute read) Reddit's infrastructure organization aims to deliver reliability and performance with a modern tech stack, which involves completely getting rid of its Python monoliths. It has four core models: Comments, Accounts, Posts, and Subreddits. Comments and Accounts have now been fully migrated from Reddit's Python monolith to domain-specific Go microservices. This post looks at how Reddit's team performed the migration and the lessons learned along the way. How We Debug 1,000s of Databases with AI at Databricks (14 minute read) Databricks has developed an AI-assisted platform to debug its thousands of databases across multiple cloud environments. This platform unifies metrics, tooling, and expert knowledge, letting engineers quickly diagnose and resolve database issues using natural language queries. The AI agent automates tasks like retrieving logs and correlating signals, resulting in up to a 90% reduction in debugging time and a faster onboarding process for new engineers. Getting from tested to battle-tested (20 minute read) Testing is essential when building reliable software. Being able to show that your code is correct and resilient can be hard, and it takes time to write good tests. In a non-trivial system, tests are an approximation at best, as the real world is messy. Going from being tested to being battle-tested requires learning some things that can only be learned through experience. 🧠 Opinions & Advice My Favorite Principle (4 minute read) "Levo's Principle" states that an object's behavior should remain constant after construction to improve code clarity, reduce bugs, and simplify refactoring. The main exception to this rule applies to procedural-style objects like stream parsers, where behavior changes are inherent to the object's purpose. Should CSS be Constraints? (10 minute read) CSS layout rules are complex and hard to pick up just from examples. One commonly-proposed replacement for CSS is a constraint system. Rule-based systems can be complex and hard to predict, but it is almost impossible to create a layout that is not under- or over-determined. A better way to improve CSS would be to provide more intuitive rule systems with more predictable, less esoteric rules. 🚀 Launches & Tools Turn your Lovable prototypes into a collaborative starting point with Atlassian (Sponsor) A prototype is worth a thousand words — and with Lovable and Atlassian, you have a clear path from vibe-coded prototype to working code. In this session, Atlassian and Lovable will demonstrate how Teamwork Collection, Rovo Dev, and Lovable make collaboration easier. See what you can create, watch the session. New npm package for automatic recovery of broken streaming markdown (1 minute read) Remend is a standalone package that brings intelligent incomplete Markdown handling to any application. It automatically detects and completes unterminated Markdown blocks to ensure clean, stable output during streaming. Remend works with any Markdown renderer as a pre-processor. It follows intelligent rules to avoid false positives and can handle complex edge cases. Fresh (Website) Fresh is a terminal text editor with features like a menu system, command palette, and full mouse support.  It's extensible with TypeScript plugins that run in a sandboxed Deno environment. Fresh has near-zero latency and can reliably handle multi-gigabyte files. 🎁 Miscellaneous ACME, a brief history of one of the protocols which has changed the Internet Security (21 minute read) The ACME protocol had a role in automating certificate management and enabling widespread HTTPS adoption. Born out of the Let's Encrypt project, ACME allows client software to automatically prove domain control to certificate authorities. RCE in React Server Components (1 minute read) A critical Remote Code Execution (RCE) vulnerability (CVE-2025-55182) affects React Server Components in Next.js versions 14.3.0-canary.77 and higher, as well as 15.x and 16.x, requiring immediate upgrade to patched versions. ⚡ Quick Links Ghostty Is Now Non-Profit (6 minute read) Ghostty, a terminal technology project, has become a non-profit fiscally sponsored by Hack Club to guarantee its sustainable, open-source development, public benefit, and legal protections. You can't fool the optimiser (4 minute read) Compilers have the ability to recognize patterns in code, even obfuscated ones, and optimize them into efficient instructions by transforming them into a simplified intermediate representation. How I Reverse Engineered a Billion-Dollar Legal AI Tool and Found 100k+ Confidential Files (5 minute read) Alex Schapiro reverse-engineered Filevine, a billion-dollar legal AI tool, and discovered a security vulnerability that granted full admin access to over 100,000 confidential files. No more tokens! Locking down npm Publish Workflows (8 minute read) Using extremely granular tokens limits the blast radius of any compromise. Love TLDR? Tell your friends and get rewards! Share your referral link below with friends to get free TLDR swag! https://refer.tldr.tech/ef788db7/3 Track your referrals here. Want to advertise in TLDR? 📰 If your company is interested in reaching an audience of web developers and engineering decision makers, you may want to advertise with us. Want to work at TLDR? 💼 Apply here or send a friend's resume to jobs@tldr.tech and get $1k if we hire them! If you have any comments or feedback, just respond to this email! Thanks for reading, Priyam Mohanty, Jenny Xu & Ceora Ford Manage your subscriptions to our other newsletters on tech, startups, and programming. Or if TLDR Dev isn't for you, please unsubscribe.