TLDR DEV 2026-04-28

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3 WAYS TO STORE VARIABLES IN REACT, AND WHY YOU SHOULDN'T SLEEP ON USEREF

There are three ways to store variables in React, with a particular focus on the `useRef` hook. Vanilla JavaScript variables are temporary and do not cause UI updates, while `useState` variables persist, update the UI, and are essential for reactive components.`useRef` allows data to persist and be mutable across renders without triggering a re-render of the UI.

SELECTIVE TEST EXECUTION AT STRIPE: FAST CI FOR A 50M-LINE RUBY MONOREPO

Stripe manages a 50M-line Ruby monorepo by using a C++ library to track file access during tests, allowing them to run only 5% of the test suite per build. This selective execution process is made reproducible by using Monotonic Revision IDs to fetch test baselines from MongoDB without needing to traverse git history.

THE UNWRITTEN LAWS OF SOFTWARE ENGINEERING

Experienced software engineers often learn critical "unwritten rules" through trial and error, such as the importance of rollback plans, rigorous backup testing, and the "four eyes" rule for risky changes. This article outlines seven essential principles that help developers create more reliable systems by avoiding operational pitfalls and temporary fixes.

MEETINGS ARE FORCING FUNCTIONS

Regular, standing meetings serve as effective forcing functions for complex, long-running projects by creating accountability and ensuring dedicated time for progress.

3 CONSTRAINTS BEFORE I BUILD ANYTHING

For creativity when building, every idea must meet three constraints. These constraints require distilling the idea into a clarity-driven "one-pager," making sure the core technology is independently viable for leverage, and defining the product by a single, guiding constraint to prevent feature bloat.

Read how Cursor cut costs 20x and improved agent reasoning

AN OPEN-SOURCE SPEC FOR CODEX ORCHESTRATION: SYMPHONY

Symphony is an open-source specification for an agent orchestrator designed to address the bottleneck of human engineers micromanaging coding agents. It transforms project management boards like Linear into control planes, continuously assigning tasks to agents in dedicated workspaces and handling their execution. The system boosts productivity, with some teams seeing a 500% increase in landed pull requests, by allowing humans to focus on higher-level, ambiguous problems rather than supervising agents.

SUP

Sup is a terminal-based email client designed for managing large volumes of mail through tagging and hierarchical threading. It has powerful local search and a Ruby hook system, making it an efficient tool for users who treat their inbox as a searchable archive.

DIRAC

Dirac is an open-source AI coding agent designed for high accuracy and token efficiency. Available as a VS Code extension and CLI, it provides a powerful, cost-effective solution that reduces API costs by an average of 64.8% through methods like optimized context curation, AST manipulation, and autonomous tool use.

THE WOES OF SANITIZING SVGS

Scratch's reliance on complex, manual sanitization for directly embedded user-generated SVGs has proven unsustainable, repeatedly failing to prevent vulnerabilities like XSS and HTTP leaks. There are other alternatives that successfully sandbox SVGs within an `iframe` using a strict Content Security Policy.

TWO YEARS WITHOUT COOKIES ON THE SITE, HERE'S WHERE WE ENDED UP

Sentry's removal of advertising cookies and tracking two years ago forced a shift toward awareness-based growth, with 70% of its budget now targeting channels like sponsorships and podcasts. This transition from pixel tracking to holistic data analysis and authentic engagement has unexpectedly driven exponential growth in new activated users.

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GITHUB COPILOT IS MOVING TO USAGE-BASED BILLING

On June 1, GitHub Copilot will transition to usage-based billing, where all plans will consume AI Credits based on token usage instead of premium requests to align pricing with actual usage.

IS YOUR SITE AGENT-READY?

This is a service to scan websites and determine their readiness for AI agents by checking against multiple emerging standards.

COLLECTIVE SPEED IS NOT THE SUMMATION OF INDIVIDUAL SPEED

A company's collective speed, much like a relay race, depends more on the effective interfaces and relationships between its people than on the individual speed of its coders.

WELCOME TO THE “FIND OUT” STAGE OF AI

As AI enters its "find out" stage, the industry is shifting from experimentation to delivering reliable real-world value for businesses.