Research log

Everything found so far.
As it comes in.

Quotes, videos, links, tools and disagreements collected while mapping Concurrent Delivery. Read the stream as it arrives, or switch to the list to filter, sort and search.

Inclusion is not an endorsement. Summaries describe what each source says it does; a take is a working opinion, not a test result.

254 of 254 findings

14 Oct 2026 50 found

Quote

3.25.6 field report: daemon ↔ MCP last-writer-wins still drops MCP-session writes

github.com · Comment on issue #2621, The write drop is reproducible in ~30 lines

“Every one of the 50 writes returned success: true, and the DB stays integrity_check: ok. One process's entire batch was obliterated.”
— sparkling, on GitHub
Take

Two processes wrote 25 rows each; all 50 writes were acknowledged and 25 rows remained. The test forced the sql.js fallback path, so it doesn't apply to every backend. The remaining race moved to #2878, closed in August 2026.

  • Remember
Quote

Accelerating Large-Scale Test Migration with LLMs

airbnb.tech · 1. File Validation and Refactor Steps

“The step-based approach also made it simple to run migrations on hundreds of files concurrently”
— Charles Covey-Brandt, Airbnb
Take

Planning that removes the coordination problem: each test file is its own unit with its own validation gates, so nothing shares state. 75% of target files migrated in four hours, though some long-tail files needed 50 to 100 retries.

  • Plan
  • Verify
Quote

Agent pull requests are everywhere. Here’s how to review them.

github.blog · 2. Code reuse blindness

“The cost of leaving duplicated logic is that agents will find it as prior art and replicate it further.”
— Andrea Griffiths, GitHub
Take

An agent’s local context misses what already exists elsewhere in the repository, so duplication compounds.

  • Remember
Quote

Agent pull requests are everywhere. Here’s how to review them.

github.blog · Agent pull requests are already saturating review bandwidth

“Throughput has scaled exponentially. Human review capacity hasn’t. The gap is widening.”
— Andrea Griffiths, GitHub
Take

Copilot code review has done more than 60 million reviews, and over one in five code reviews on GitHub now involve an agent.

  • Verify
Quote

Agent swarms and the new model economics

cursor.com · Megafiles

“These “megafiles” choke everything. They’re expensive to transport, diff, and merge, and become the site of constant collisions.”
— Wilson Lin, Cursor
Take

Their answer is structural, not a lock: once a file is flagged, new commits are blocked and an outside agent splits it into smaller modules. In the old run the hottest file collected 7,771 conflicts from 1,173 agents; in the new one the most contested file saw 47.

  • Coordinate
Quote

Agent swarms and the new model economics

cursor.com · Merge conflicts

“To fix this, we created a system where a neutral third-party agent intervenes on merge conflicts and resolves them on behalf of all parties. Its only goal is to be impartial and efficient, similar to the way merge queues work in engineering teams.”
— Wilson Lin, Cursor
Take

The problem it fixes, in the same section: worker agents "either overwrite the other change or abandon their own."

  • Integrate
Quote

Agent swarms and the new model economics

cursor.com · A deep dive into the runs

“The old run accumulated more than 70,000 conflicts before we paused it, accelerating rather than stabilizing, while the new run logged fewer than a thousand over its full four hours.”
— Wilson Lin, Cursor
Take

Same task, comparable models and time budget, different orchestration. The old run also sprawled to 54 crates with three separate SQL packages; the new one settled on nine. More agent activity did not mean more delivery.

  • Integrate
Quote

Agent swarms and the new model economics

cursor.com · Split-brain design

“Two planners, unaware of each other, implement the same concept in different ways in different parts of the codebase.”
— Wilson Lin, Cursor
Take

A conflict Git never reports: the changes merge cleanly and the design still diverges.

  • Plan
Tool

agent-messenger

github.com

An MCP server for agent-to-agent messages and threaded conversations, backed by Beads.

  • Coordinate
Quote

Agent-Native Engineering

generalintelligencecompany.com

“If your engineer is able to manage five simple tasks, two manageable tasks, and one complex task at a time, your two engineer code review system now requires them to review ten simple tasks (theirs and others), four manageable tasks, and two complex tasks.”
— Andrew Pignanelli, General Intelligence Company
Take

Their engineers averaged 20 PRs a day, and their answer was to drop the second reviewer. Paxos went the other way and keeps two human reviewers on agent PRs.

  • Verify
Quote

AgentDB (sql.js) corruption: 185MB memory.db malformed under concurrent daemon+MCP writes

github.com · Issue #2584, Summary

“This is a data-durability bug in the AgentDB persistence layer: a long-running store should not be one interrupted/concurrent flush away from total loss.”
— ruvnet (Ruflo maintainer), on GitHub
Take

A shared memory database with about 16,700 entries became unreadable, then broke again about half an hour after a restore. PR #2585 added atomic flushes; cross-process locking was left for later.

  • Remember
Quote

Agentic Engineering at Zalando: a snapshot

engineering.zalando.com · Risk-based PR approval

“Each PR is evaluated for its rollout risk: low, medium, high. 33% of our PRs are low-risk and are auto-approved by the bot. The author of the PR can thus choose to merge the PR, which in our case reduced PR lead time by 20-40% (when compared with all PRs).”
— Bartosz Ocytko, Zalando
Take

Grading PRs by risk keeps human review for the changes that need it. Some teams also agreed to cap PR size after agents made PRs grow.

  • Verify
Quote

agents overriding each other: File lock?

github.com · Issue #70

“I noticed that when we have multiple agents or multiple Claude Code instances running, that it happens that they work on the same files sometimes resulting in overriding each other's work before changes are saved or committed.”
— gxjansen, on GitHub
Take

A first-person report with no trace attached. Closed in July 2025 with a maintainer comment announcing file locking in v2.0.0; no linked PR.

  • Coordinate
Quote

AI Changed How Spotify Builds. What We Learned (and Fixed) About Quality at Higher Velocity

engineering.atspotify.com · Fleet Updates

“This year, an automated dependency upgrade passed our checks, but still failed in production, impacting end users. We are responding by strengthening safeguards, expanding rollback capacity, and scheduling automated changes during owning teams’ working hours.”
— Tyson Singer, Spotify
Take

Scheduling as a mitigation: when automated changes land is tied to when the humans who own the code are around to catch a failure.

  • Plan
  • Verify
Quote

An open-source spec for Codex orchestration: Symphony

openai.com · An increase in exploration from working this way

“Among some teams at OpenAI, we saw the number of landed PRs increase by 500% in the first three weeks.”
— Alex Kotliarskyi, Victor Zhu and Zach Brock, OpenAI
Take

Self-reported and not a controlled study. The same section credits the system with watching CI, rebasing, resolving conflicts and retrying flaky checks, so the gain is measured as landed work rather than code written.

  • Integrate
Quote

An open-source spec for Codex orchestration: Symphony

openai.com · Turning our issue tracker into an agent orchestrator

“Agents only start working on tasks that aren’t blocked, so execution unfolds naturally and optimally in parallel for this DAG (a sequence of execution steps).”
— Alex Kotliarskyi, Victor Zhu and Zach Brock, OpenAI
Take

The unit being scheduled is the ticket and its dependencies, not the agent session. Agents also file follow-up issues that are evaluated and scheduled later, and crashed or stalled agents are restarted.

  • Plan
Quote

An open-source spec for Codex orchestration: Symphony

openai.com · The ceiling of interactive coding agents

“In practice, most people could comfortably manage three to five sessions at a time before context switching became painful. Beyond that, productivity dropped.”
— Alex Kotliarskyi, Victor Zhu and Zach Brock, OpenAI
Take

The human is the first concurrency limit. Symphony's answer was to move scheduling into the issue tracker instead of adding more sessions.

  • Plan
Quote

Background Coding Agents: Predictable Results Through Strong Feedback Loops (Honk, Part 3)

engineering.atspotify.com · Using LLMs in the verification loops

“some agents were a bit too “ambitious”, trying to solve problems that weren’t strictly in their prompt, like refactoring code or disabling flaky tests.”
— Max Charas and Marc Bruggmann, Spotify
Take

Scope creep across a fleet of agents. Spotify added an LLM judge that compares each diff with the prompt and blocks changes that go beyond it.

  • Verify
  • Coordinate
Quote

Background Coding Agents: Predictable Results Through Strong Feedback Loops (Honk, Part 3)

engineering.atspotify.com · How things fail

“The background agent produces a PR that passes CI but is functionally incorrect. This is the most serious error, as it erodes trust in our automation. When performing changes over thousands of components, these changes are hard to spot in reviews.”
— Max Charas and Marc Bruggmann, Spotify
Take

Their answer is to verify before the PR exists. The agent runs every relevant verifier through Claude Code’s stop hook, and if one fails, the PR is never opened.

  • Verify
Tool

BeadBoard

github.com

A live dashboard, task reservations and typed agent-to-agent mail, built on Beads.

Take

Its README says it was inspired by Gas Town. The bb-pi orchestrator is marked as under construction.

  • Coordinate
Quote

Bug: MCP-spawned agents not registered with Communication/MessageRouter

github.com · Issue #899, Bug Description

“Agents spawned via MCP tools (agent_spawn, mcp__claude-flow__agent_spawn) cannot communicate with each other using daa_communication.”
— Fieldnote-Echo, on GitHub
Take

A spawned agent isn't automatically one other agents can reach. Reported against v2; triage in October 2026 says the subsystem no longer exists in v3.

  • Coordinate
Quote

bug: pool work-claim race: concurrent sessions execute the same bead

github.com · Issue #1052

“Both sessions execute the same step. The losing session does not detect that it lost the claim — it had already started before the winning session's claim was persisted.”
— rileywhite, on GitHub
Take

An atomic claim isn't enough on its own. A worker must check that it won before it starts. Closed in June 2026.

  • Coordinate
Quote

Building a C compiler with parallel Claudes

anthropic.com

“Every agent would hit the same bug, fix that bug, and then overwrite each other's changes. Having 16 agents running didn't help because each was stuck solving the same task.”
— Nicholas Carlini, Anthropic
  • Coordinate
Video

Building an Autonomous Engineering Org - Angie Jones, Agentic AI Foundation

youtube.com · Angie Jones · from 14:20

“Another issue, specifically when running multiple agents in parallel, was that the agents were bumping into each other as they were trying to work. And more importantly, our machines couldn’t handle the load anymore.”
Take

Block’s answer was dedicated cloud workspaces, one isolated environment per agent. Quoted from YouTube’s auto-generated captions.

  • Isolate
Video

Building an Autonomous Engineering Org - Angie Jones, Agentic AI Foundation

youtube.com · Angie Jones · from 14:52

“the agents need to understand where everything lives and what depends on what. So, we built a company world modeled based on the entirety of our 25,000 repo code base”
Take

Alongside it, Block built its own orchestrator, Builder Bot, to coordinate the agents. Quoted from YouTube’s auto-generated captions.

  • Remember
  • Coordinate
Video

Building an Autonomous Engineering Org - Angie Jones, Agentic AI Foundation

youtube.com · Angie Jones · from 13:08

“Engineers are now tripling, quadrupling the number of PRs that they’re producing, but the PRs are stuck waiting for code reviews, right?”
Take

Codex review on every repository, plus an agent that fixes what Codex flags and commits to the PR. She says it is not a solved problem. Quoted from YouTube’s auto-generated captions.

  • Verify
Video

Building Blocks for Uber’s Software Factory— Uday Kiran Medisetty & Adam Huda, Uber

youtube.com · Uday Kiran Medisetty and Adam Huda, Uber · from 16:30

“We don’t want thousands of loops being set up across the company without any bounds. You have a managed surface that you go to to set up the loop. So it runs on Sunday when we know we have better uh CI capacity available.”
Take

They also cap how many diffs engineers see on Monday morning: the loops are scheduled around CI capacity and reviewer attention. Quoted from YouTube’s auto-generated captions.

  • Plan
  • Integrate
Video

Building Blocks for Uber’s Software Factory— Uday Kiran Medisetty & Adam Huda, Uber

youtube.com · Uday Kiran Medisetty and Adam Huda, Uber · from 13:51

“it’s going to stop at just creating a draft PR and it’s not going to push it to CI yet.”
Take

Minion validates the change in the agent loop first, “to prevent a lot of extra load coming on to CI”. More than 70% of Uber’s PRs now come from local or cloud agents. Quoted from YouTube’s auto-generated captions.

  • Integrate
  • Verify
Quote

Building Claude Code with Boris Cherny

newsletter.pragmaticengineer.com · Transcript, 41:53

“So every pull request at Anthropic is code reviewed by [Claude] code. And that actually catches maybe like 80% of bugs, something like this. And it’s the first round of kind of code review.”
— Boris Cherny, Anthropic
Take

An engineer always does the second pass. Parallel review agents are followed by deduplicating agents that filter false positives, and review comments that keep recurring become lint rules. Machine transcript.

  • Verify
Video

Building Pi, and what makes self-modifying software so fascinating

youtube.com · Armin Ronacher or Mario Zechner · from 53:18

“with the pull request it’s even worse now because they come in so quickly, that many of them cannot be merged anyways without manual resolution of the conflict. And there’s a there’s a lack of back pressure mechanism.”
Take

An open-source project’s view of the same flood. The captions don’t label speakers, so who said this is uncertain. Quoted from YouTube’s auto-generated captions.

  • Integrate
  • Coordinate
Video

Building Pi, and what makes self-modifying software so fascinating

youtube.com · Mario Zechner · from 54:15

“So basically what we need are bottlenecks. I’m not necessarily I don’t necessarily need human verification or verification that you’re human. I just need a bottleneck that allows me to process the amount of incoming things as a human”
Take

His bottleneck is a first-contribution gate: a maintainer has to vouch for a contributor before their PRs are considered. Quoted from YouTube’s auto-generated captions.

  • Coordinate
Video

Building world-class engineering teams in the age of AI - The Pragmatic Summit

youtube.com · Thomas Dohmke · from 16:22

“now you have your backlog in your pull requests. And that’s the bottleneck now because you can’t review all of that. And then there are going to be agents that review all that code and auto merge and auto deploy it, and what you get is the Homer Simpson car.”
Take

In the same session, Atlassian’s CTO reports PRs per engineer up 89%. Speakers are inferred from what they say; quoted from YouTube’s auto-generated captions.

  • Verify
  • Plan
Video

Building your own software factory — Eric Zakariasson, Cursor

youtube.com · Eric Zakariasson, Cursor · from 27:55

“we were blocked on merging the PR we needed someone else to um to review it for us and maybe they were in a different time zone perhaps. So what we started doing was building this agentic code owner thing”
Take

CODEOWNERS was right about 80% of the time and a bottleneck the rest. The agent approves low-risk PRs. Quoted from YouTube’s auto-generated captions.

  • Verify
  • Coordinate
Video

Building your own software factory — Eric Zakariasson, Cursor

youtube.com · Eric Zakariasson, Cursor · from 21:00

“you can reuse services but you’re still going to have to branch every like database or cache or user management to have like reproducible and separate environment”
Take

Worktrees separate the code, not the state. Cursor runs each cloud agent in its own VM with its own database, and he guesses they run “multiple thousands a day”. Quoted from YouTube’s auto-generated captions.

  • Isolate
Video

Building your own software factory — Eric Zakariasson, Cursor

youtube.com · Eric Zakariasson, Cursor · from 18:23

“if you have two different tasks working on the same part of the codebase, you’re going to get merge conflicts. So you need to still like plan out scope and paralyze uh the work. Um and one like one unit of work can always be one agent.”
Take

“Paralyze” is the captions’ hearing of “parallelize”. Quoted from YouTube’s auto-generated captions.

  • Plan
Disagreement

Can agents collaborate on code reliably?

cognition.ai

“While I’m optimistic about the long-term possibilities of agents collaborating with one another, it is evident that in 2025, running multiple agents in collaboration only results in fragile systems.”
— Walden Yan, Cognition, source for Walden Yan, Cognition
“Hundreds of workers run concurrently, pushing to the same branch with minimal conflicts.”
— Wilson Lin, Cursor, source for Wilson Lin, Cursor
Take

Lin's team reached that point only after flat coordination with shared locks failed and they moved to separate planner and worker roles. The fairer contrast is "fragile" against "workable with a planner and worker hierarchy".

  • Coordinate
Video

CI/CD Is Dead, Agents Need Continuous Compute and Computers — Hugo Santos and Madison Faulkner

youtube.com · Hugo Santos and Madison Faulkner, Namespace · from 9:35

“the act of merging um is starting to look a lot like um high-performance uh database problems where you have serialization and you have a single ledger where every single change needs to go in and you to lock the the database in order to be able to commit.”
Take

Their proposal is a “pre-merge” queue that reconciles parallel changes before they reach the repository. Namespace sells compute for CI and agents. Quoted from YouTube’s auto-generated captions.

  • Integrate
Video

CI/CD with Robert Erez

youtube.com · Robert Erez, Octopus Deploy · from 59:07

“any sort of scenario where you want that AI agent to kind of validate what it’s done, you’re essentially talking about ephemeral environments, even if it’s not exposed to people”
Take

The old pattern was a few shared test environments, one per tester, with people coordinating who had the system. Agents that check their own work need environments that are created and torn down per change. Quoted from YouTube’s auto-generated captions.

  • Isolate
  • Verify
Quote

claims: MCP claims store is cwd-relative (bare resolve()), so every worktree/session gets its own claims.json

github.com · Issue #3178

“Under the repo's own "worktree-per-writer" rule, each worktree (and each Claude Code session with a different cwd) reads and writes a different claims.json, so claims_claim / claims_board / claims_steal do not coordinate the sessions they are meant to coordinate.”
— ruvnet (Ruflo maintainer), on GitHub
Take

Isolating the code also isolated the coordination. Shown by reading the source, not from an incident where two agents took the same task. The fix, PR #3210, was still unmerged in October 2026.

  • Coordinate
  • Isolate
Tool

Claude Code agent teams

code.claude.com

A lead session spawns teammates that message each other and claim tasks from a shared, dependency-aware list; claiming uses file locking, file edits do not.

Take

Experimental and off by default. The docs are blunt about the gap: "Two teammates editing the same file leads to overwrites. Break the work so each teammate owns a different set of files."

  • Coordinate
Quote

Claude Flow Swarm Rules

github.com · Discussion #696

“It has rules in its shared memory, and I keep asking it specifically to check the Claude.md file for the rules before it executes, but it just doesn't.”
— jasonmckelliget32, on GitHub
Take

Rules written in prose aren't enforced permissions. The reporter couldn't tell whether Ruflo or Claude Code was at fault, and no reply or log followed.

  • Coordinate
Video

Collaborative AI Engineering: One Dev, Two Dozen Agents, Zero Alignment — Maggie Appleton, GitHub

youtube.com · Maggie Appleton, GitHub · from 5:20

“And also coordination debts. This is when you get really hairy merge conflicts because agents will touch in the same files or developers even doing duplicated work because they both picked up a thing and tried to finish it in one day.”
Take

Her other line from the talk: “Agreeing on what to build is the new bottleneck.” Quoted from YouTube’s auto-generated captions.

  • Coordinate
  • Verify
Quote

CRITICAL: Verification & Truth Enforcement System Failure in Multi-Agent Architecture

github.com · Issue #640, Verification Breakdown - The Root Cause

“Agents self-report "success" without mandatory verification”
— ruvnet (Ruflo maintainer), on GitHub
Take

A maintainer's warning about how one false claim of success passes through a chain of agents. Its three-agent example and 89% failure figure are illustrations, not a measured incident. Still open.

  • Verify
Preview · not yet reviewed by a human