Behavioral differences from Claude Opus 5 and the prompting and harness patterns that address them: effort calibration, thinking behavior in API integrations and chat, progress updates, unattended and multiagent tasks, safeguard refusals, frontend design, complex visual inputs, multi-app workflows, and pasted text in user messages.
Rapidly scaling online storage to serve over 1 billion ChatGPT users
Learn how OpenAI evolved Habitat from a Python library into a globally distributed storage platform serving 1 billion ChatGPT users and 22M requests per second.
One of the interesting challenges of the AI ecosystem in 2026 is that new,
effective patterns emerge faster than I can adopt them. I’ll find a handful,
get back to work, and realize a month later that I’d missed four or five more.
The adoption cycle for Imprint this year has been something like:
January: get every engineer onto Claude Code every single day
March: ok, let’s also get everyone else onto Claude Code or Claude Cowork every single day
April: local development is bottlenecked on checkout and worktree model,
instead create ~10 local workspaces which each have an independent checkout of every repository,
and operate at the workspace level, not at the repository level, so it can generate cross-repository
pull requests across frontend, backend, infrastructure and data monorepos
June: oh boy, agent-driven development is heavily constrained by lack of a common task management
system with higher visibility and less permission complexity than Jira,
so let’s migrate the entire company over to Linear and hard stop on Jira
July: yikes, now we have visibility into all these tickets, many of them are trivial
but managing them through local development isn’t scaling, let’s roll out an orchestrated harness
which internally we call “Agent Fleet”,
along the lines of Stripe’s Minions
The most recent question for me has been figuring out how to adopt the software factory pattern.
(After some light research, the specific AI-context origin of this term is slightly messy to
attribute, but I think it might be Justin McCarthy in February 2026’s
Software Factories And The Agentic Moment.)
AI coding has made CI a bottleneck, so we reworked ours to keep up
We cut PR wait time and running costs by rethinking CI as a system, from the infrastructure underneath it to how work gets scheduled and tests get parallelized.
Lovable previews are moving to OJ, a Rust-native dev server that starts them several times faster on a fraction of the memory. We are rolling it out gradually, and today OJ is open source in the Lovable GitHub organization.
Devframe is a framework-neutral foundation for devtools. One definition becomes a Web Standard handler you can mount into any host framework, ship as a CLI or static report, and expose to coding agents.
Control GitHub Actions cache access with cache-mode - GitHub Changelog
You can now use cache-mode to apply least-privilege access to the GitHub Actions cache at the workflow or job level. By granting each workflow or job only the cache access…
Jev introduces a new shape of LLM—System One, aka Decision Models
Last week TypeSafe AI unveiled Jev, their first example of a new category of model that they are calling “System One models” (I’m with Maggie Appleton, I think “decision models” …
Generative design of novel bacteriophages with genome language models
Many important biological functions arise not from single genes, but from complex interactions encoded by entire genomes. Genome language models have emerged as a promising strategy for designing biological systems, but their ability to generate functional sequences at the scale of whole genomes has remained untested. Here, we report the first generative design of viable bacteriophage genomes. We leveraged frontier genome language models, Evo 1 and Evo 2, to generate whole-genome sequences with realistic genetic architectures and desirable host tropism, using the lytic phage ΦX174 as our design template. Experimental testing of AI-generated genomes yielded 16 viable phages with substantial evolutionary novelty. Cryo-electron microscopy revealed that one of the generated phages utilizes an evolutionarily distant DNA packaging protein within its capsid. Multiple phages demonstrate higher fitness than ΦX174 in growth competitions and in their lysis kinetics. A cocktail of the generated phages rapidly overcomes ΦX174-resistance in three E. coli strains, demonstrating the potential utility of our approach for designing phage therapies against rapidly evolving bacterial pathogens. This work provides a blueprint for the design of diverse synthetic bacteriophages and, more broadly, lays a foundation for the generative design of useful living systems at the genome scale.
### Competing Interest Statement
B.L.H. acknowledges outside interest in Arpelos Biosciences and Genyro as a scientific co-founder. S.H.K. and B.L.H. are named on a provisional patent application applied for by Stanford University and Arc Institute related to this manuscript. All other authors declare no competing interests.
Arc Research Institute, https://ror.org/00wra1b14
Stanford Institute for Human-Centered Artificial Intelligence
HarnessRouter/harnessrouter: HarnessRouter Community Edition: the self-hosted, Apache-2.0 edition of the unified interface for agent harnesses. Run Codex, Claude Code, Hermes, PI, DSH, and more through one API, with sessions, streaming, files, cancellation, and failure handling. Implements the Unified Harness Protocol (UHP), an open standard. Your keys, your infrastructure.
HarnessRouter Community Edition: the self-hosted, Apache-2.0 edition of the unified interface for agent harnesses. Run Codex, Claude Code, Hermes, PI, DSH, and more through one API, with sessions, ...
Active Storage Image Optimization: 1,916 Photos, One Box
What Active Storage does at scale: variants built inside the request, the preprocessed trap, AVIF measured 31.6% under WebP, and the CDN check we failed.