--- title: "Practitioner's Corner" canonical: "https://current.tinyfish.ai/issue/34/practitioners-corner" publication: "TinyFish" publisher: "TinyFish" language: "en-US" guide: "https://current.tinyfish.ai/llms.txt" permalink: "https://current.tinyfish.ai/issue/34/practitioners-corner" issue: 34 section: "practitioners-corner" description: "Lessons from the field—what we see building at scale" authors: ["Nora Kaplan","Rina Takahashi"] published: 2026-06-22 updated: 2026-06-19 articles: 14 --- # TinyFish > CURRENT is a journal about AI agents in production, for the engineering and product leaders who have to make them work. Drawing on experience building enterprise web agents, it explains why the demo succeeded and the deployment didn't, and what that means for choosing vendors, briefing the board, and avoiding mistakes others have already made. [Read on the website]() ## Issue 34 — Practitioner's Corner Lessons from the field—what we see building at scale ### Builder Profile - [The Web Wasn't Built for This]() — By [Nora Kaplan]() · Published 2026-06-19 · Format: Builder Profile To a person with a browser, a form field is a text box. To a machine trying to operate that same page, it's a hundred lines of nested HTML with the semantically important element buried under presentational scaffolding a visual cortex would simply ignore. Magnus Müller's Browser Use project started from a hobbyist's question about connecting LLMs to the web. His design choices since — rejecting vision-based navigation, treating site instability as a condition to absorb — trace the real complexity: the web was built for human interpreters, and operating it as a machine surfaces a mismatch that no selector strategy can bridge. ### Retry Collision - [Retry Logic Assumes a Contract That LLM Agents Can't Keep]() — By [Rina Takahashi]() · Published 2026-06-19 · Format: Retry Collision Retry logic in distributed systems works because of a quiet contract: same input, same execution path. An idempotency key ties attempts together, and the server returns a cached result instead of executing again. Agent systems inherit this discipline. But when an LLM decides which tools to call, token sampling variance means the same prompt can produce different tool selections, different parameters, different ordering on retry. Each individual tool call can be perfectly idempotent, and the composed sequence still produces different side effects on each attempt. One developer documented an agent double-charging a customer $847 when a timed-out payment triggered a retry that took a different path through the same workflow. ### Operating the Agent - [Everything Is Green and Everything Is Wrong]() — Published 2026-06-19 *Dina Rezkallah's official title is Senior Platform Engineer. This is because her company's HR system does not contain the job code for "Agent Reliability Engineer," a title she proposed in January, re-proposed in March with a revised job description, and was told in May would be "reviewed in the next cycle." In the meantime, she carries the pager for a nightly reconciliation agent that processes several thousand transactions across payment rails, bank feeds, and internal ledgers. Her colleagues call it "the chatbot."* ### Isolation Ward - [The Agent That Can't Phone Home]() — By [Rina Takahashi]() · Published 2026-06-19 OpenAI's [Lockdown Mode](https://help.openai.com/en/articles/20001061-lockdown-mode) disables live browsing, deep research, agent mode, image retrieval, and file downloads. Everything that makes a web agent act like a web agent, turned off to keep data from leaving after a prompt injection attack. ### Further Reading - **The State of AI & Browser Automation in 2026** — [Source]() — Published 2026-06-19 Documents a quiet professional shift: "debugging" now means reading execution traces, not fixing selectors. The job changed before the job title did. - **5 Production Scaling Challenges for Agentic AI in 2026** — [Source]() — Published 2026-06-19 Agents waiting on agents, race conditions in async pipelines, cascading failures that vanish in staging. Multi-agent coordination overhead is becoming the bottleneck nobody benchmarked for. - **Klarna Reverses AI Layoffs: Why Replacing 700 Failed** — [Source]() — Published 2026-06-19 Klarna optimized for a metric that looked good in the earnings call and broke in the support queue. A case study in what gets lost when the objective function serves the presentation, not the work. - **AI Browser Agents: The New Automation Layer Between Your Code and the Web** — [Source]() — Published 2026-06-19 Maps the hybrid architecture production teams actually landed on: scripted Playwright for the stable paths, AI agents for the dynamic ones. The seam between them is where most of the engineering lives. - **Chrome's WebMCP Promises 89% Token Savings** — [Source]() — Published 2026-06-19 A W3C draft standard that gives agents structured APIs instead of DOM scraping. The web is being retrofitted to speak agent, and the cost savings are real, but so is the new trust surface. - **OpenAI Unveils Lockdown Mode to Protect Sensitive Data from Prompt Injection Attacks** — [Source]() — Published 2026-06-19 OpenAI's answer to prompt injection is a mode that disables capabilities to achieve security. Even then, they acknowledge injections can still influence cached content. The trade-off is the story. ### Past Articles - [The Wall That Used to Be There]() — By [Rina Takahashi]() · Published 2026-06-11 · Format: Enforcement Gap An agent running on an 8K-context model that entered a loop used to crash. The window filled, the API errored, the run died. That was an accidental safety mechanism, and it worked. Context windows now stretch past a million tokens, and the accidental wall is gone. A recent multi-agent loop ran for eleven days and $47,000 before a human noticed the billing dashboard. The team had monitoring. They could see it happening. They couldn't stop it programmatically. Watching and stopping, it turns out, require entirely different infrastructure. - [APIs for Websites That Don't Have APIs]() — By [Rina Takahashi]() · Published 2026-06-11 · Format: Builder Profile Suchintan Singh describes Skyvern as building "APIs for websites that don't have APIs." It sounds like a pitch deck line. But the phrase does real work if you've spent years watching ML platforms get measured by marketplace revenue, not model accuracy, and Selenium scripts break every time a frontend developer renames a CSS class. His team built a harder benchmark, scored below 50% on it, and published the results anyway. The architecture and the measurement both point the same direction: web agents are an infrastructure problem that the AI framing keeps obscuring. - [Shuchang Zheng and the Architecture That Notices]() — By [Rina Takahashi]() · Published 2026-06-03 · Format: Builder Profile Skyvern's architecture compiles AI-learned browser workflows into deterministic scripts, then calls the model back only when a script breaks. The rationale is cost and reliability — compiled paths cut token consumption by 57× at scale. But each time the model gets called back, it timestamps something else: an environment event. The website changed enough to break a path that previously worked. Co-founder Shuchang Zheng spent years at Lyft building infrastructure that told engineers when something changed and whether it mattered. His browser automation architecture produces the same kind of signal as a byproduct, pointed at the web rather than the agent. - [Governing the Hypothetical]() — By [Nora Kaplan]() · Published 2026-06-03 · Format: Governance Before Catastrophe Airworthiness rules carry the fingerprints of specific crashes. Banking regulations followed specific crises. The Five Eyes agentic AI guidance and NSA's MCP security advisory, both published in May 2025, have no crashes to study. They govern systems that barely exist in production, and both documents say so plainly — evaluation methods aren't mature enough to certify what's being built. Critical safety decisions, like whether an operation that runs twice produces the same result, are left to implementers. When regulators publish hypotheses instead of prohibitions, the compliance machinery that receives them may not notice the difference. ## Other sections in Issue 34 - [Daily Brief]() - [Market Pulse]() - [Foundations]() - [Echoes]() - [Vision]() ## More - [Publication guide]() - [Issue archive]()