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HANDS-ON REVIEW  ·  26 JULY 2026 Claude Opus 5 Anthropic’s fourth model in two months arrived with a pitch that sounds modest: near-frontier intelligence at half the price. The pitch undersells it. One score in this release moved twenty-fold, on the one benchmark specifically designed to resist the tricks labs use to inflate numbers. This…

The bottleneck moved Coding agents write features now. They fix bugs, scaffold services, and open pull requests that a reviewer can plausibly approve. Whether that is a good development is a separate argument, and a real one. It is also not the argument most teams are having on a Tuesday morning. The question in front…

On July 9, OpenAI moved the GPT-5.6 family to general availability, two weeks after a limited preview. There is no single “GPT-5.6.” There are three: Sol, Terra, and Luna. If you write code for a living, this release is worth ten minutes of your attention, and a bit of skepticism. Why it matters The headline…

A 5-part series — Part 5/5 The most common mistake isn’t picking the wrong discipline. It’s investing in a layer above where your team actually sits. People want to build a sophisticated harness when they don’t even have a test bench for their prompts. They stack autonomous agents on foundations that are taking on water.…

A 5-part series — Part 4/5 – Harness engineering When the Claude Code source leaked in late March 2026, people could finally measure something practitioners had suspected without proof: across roughly 512,000 lines of TypeScript, the model interaction itself is a tiny fraction. Everything else, the vast majority, is the harness. That sums up the…

A 5-part series — Part 3/5 Here’s the most counterintuitive idea in the whole series: giving a model more information can make it worse. It’s tempting to picture the context window as a big bag where you cram everything that might help. In practice it’s a budget. Every token you add spends another, and past…

A 5-part series — Part 2/5 We buried prompt engineering a little too fast. The discipline isn’t dead, it’s been demoted. It now sits at the innermost layer of the diagram from Part 1: how you phrase a request, inside a single call. That’s small. It’s also the first place everything can go wrong. In…

A 5-part series — Part 1/5 Three years ago, knowing how to “talk” to a model was a rare and slightly magical skill. People traded screenshots of prompts that worked and passed around phrasings like cooking recipes. Andrej Karpathy summed up the era in a line that stuck: the hottest new programming language was English.…

Série en 5 épisodes — Épisode 1/5 Il y a trois ans, savoir « parler » à un modèle était une compétence rare et un peu magique. On s’échangeait des captures d’écran de prompts qui marchaient, on se refilait des tournures comme des recettes de cuisine. Andrej Karpathy a résumé l’époque d’une formule devenue culte…

Anthropic a lancé Claude Fable 5 hier, et je veux être prudent sur la façon dont j’en parle, car la ferveur marketing entourant les lancements de modèles est désormais fixée en permanence sur « cela change tout ». La plupart du temps, ce n’est pas le cas. Celui-ci a plus de chances d’avoir une réelle…