Stack Moves: Slack kills SSH, Stripe's one-PR TypeScript migration, Anthropic overtakes OpenAI

Slack replaces SSH job execution with REST gateway “Quarry”

Slack eliminated SSH access to its production Amazon EMR clusters, moving 700+ Airflow-orchestrated jobs onto Quarry, an internal REST-based job submission gateway. The old pattern (Airflow SSHing straight into EMR master nodes to run Spark, Hive, and shell jobs) had worked since 2017, but it left jobs to become “zombies” that kept running after a dropped connection, and it made SSH key rotation and audit logging a mess across eight independent data regions. Quarry now handles Spark and Hive traffic through existing REST APIs (Livy, HiveServer2) and routes everything else, including 300+ jobs that were just arbitrary shell commands, through YARN’s little-known Distributed Shell feature, which runs any script inside a managed, resource-isolated container. The payoff: zero downtime across a three-quarter migration, and it unblocked Slack’s move to Spark on Kubernetes, which the lingering SSH dependency had been blocking outright. (Slack Engineering, confirmed)

Stripe’s one-PR, 3.7M-line Flow-to-TypeScript migration

Worth re-surfacing because it’s still the reference case everyone cites: in 2022, Stripe converted the entire Flow codebase behind its Dashboard — 3.7 million lines — to TypeScript in a single pull request, merged on a Sunday so hundreds of engineers could start writing TypeScript the next morning. The trigger wasn’t taste, it was pain: Flow’s type checker was slow enough to lock up laptops, editor integration was flaky, and TypeScript’s tooling and community had pulled decisively ahead. The initial conversion pass left tens of thousands of error suppressions that engineers worked through incrementally rather than blocking the cutover on a fully clean pass. Stripe open-sourced its conversion tooling afterward. Four years on, it remains the case teams cite when arguing a big-bang PR beats a slow incremental migration. (Stripe Dev Blog, confirmed)

Supabase survey: Anthropic overtakes OpenAI as the default model provider

Supabase’s State of Startups 2026 survey of 2,000 founders and builders shows Claude Code as the single most-named must-have dev tool (31%, ahead of VS Code at 22% and Cursor at 15%, which dropped 19 points). On the model-provider question, Anthropic climbed from 38% to 64% year-over-year while OpenAI slid from 69% to 51% — a genuine lead change, not just a narrowing gap. Paid Claude subscriptions nearly doubled, from 28% to 59% of respondents. The more striking number is about who’s writing the code at all: 62% of startups now have more than half their codebase AI-generated, and 41% are past three-quarters. This is Supabase’s own survey data, not a third party’s read on it — treat the provider-share numbers as self-reported by respondents, not independently audited. (Supabase, confirmed)

Research assisted by AI agents, verified and edited by a human. Confidence labels: confirmed / inferred / reported. Spot an error? We correct publicly.