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How your best developers become your biggest bottleneck

The code review doom loop

Paul Sanglé-Ferrière

Dec 19, 2025

Your fastest developers are writing code in hours that sits in review for days. Not because the code is bad, but because the few team members qualified to review it are drowning in 47 other pull requests.

This dependence on a few senior engineers to move work forward costs you more than you think. Teams rely on their judgment, but nothing moves forward when these seniors are barely available. And this is how the code review doom loop begins. 

TLDR

  • Senior developers gradually accumulate most of the review load, which slows down the entire delivery process.

  • Studies show that developers spend 20-30 percent of their week waiting on reviews, and seniors spend up to half of their time reviewing code.

  • Delayed reviews lead to larger PRs, higher cognitive load, and more context switching.

  • Bottlenecks grow silently until they affect throughout and create a cycle of slowdowns.

  • AI-assisted code review tools  shorten review times, free up senior developers, and keep the delivery process more predictable.

What we mean with code review doom loop

The code review doom loop is a repeating cycle where slow reviews create conditions that make future reviews even slower.

It usually appears like this:

  1. Senior reviewers take on most of the review load.

  2. Review queues grow.

  3. Developers wait longer and begin merging work into large PRs.

  4. Larger PRs require more time and more mental effort.

  5. Seniors are trying to clear queues, so there is little time left for deep engineering.

  6. The backlog of PRs to reviews keeps growing

It is a compounding problem. The longer it continues, the harder it is for a team to regain momentum.

How common are code review bottlenecks?

Industry reports show the same patterns across engineering teams:

  • Many developers wait a day or more for initial code review feedback, with a significant share experiencing delays of 2–3 days or longer.

  • Larger pull requests usually take longer to be picked up. This ends up increasing the overall review cycle time.

  • The median time to first review in typical teams is around 15 hours, but some teams take 23 hours or more.

  • Developers often spend several hours per week on code review activities, representing a meaningful portion of their work time.

Why can senior developers turn into bottlenecks?

1. Specialized knowledge sits with a small group

Architecture, domain logic, edge behaviors, and historical context often lie with a few experienced developers. Naturally, most PRs end up needing their input.

2. Fear of regression leads to over-reviewing

Teams want to avoid production issues, so they rely on senior reviewers even for minor or low-risk changes.

3. When reviews take longer, developers start submitting bigger PRs

Smaller PRs do not feel worth opening when response times are slow. Developers wait, batch changes, and send larger PRs that take increasingly longer to review.

4. High cognitive load builds up

Reviewing is mentally demanding, even for very experienced developers. It requires loading the full mental model of the feature, the code path, the edge cases, and the potential impact.

The more PRs in the queue, the harder it is to maintain high quality.

How do review bottlenecks impact delivery?

1. Longer review cycles delay everything downstream

Slow reviews delay merges, testing, deployment, and sometimes entire sprints. One PR stuck in review can cause a chain reaction of delays.

2. Developers lose momentum

When feedback is slow, engineers switch tasks, start new work, and might even leave projects half done. This creates additional cognitive overhead and more context switching across the team.

3. Quality suffers when reviewers rush

When queues get long, reviewers tend to skim, rely on intuition, or overlook subtle issues.

4. Team morale declines

Developers feel blocked. Senior engineers feel pulled in too many directions. Everyone feels like progress depends on the availability of a few people.

The hidden cost: morale, focus, and innovation

Code review bottlenecks also influence team morale and the ability to innovate. Overloaded reviewers have less capacity for deep work, and developers waiting for feedback often lose momentum. You quickly find your team in a reactive work environment where engineers only focus on clearing queues instead of tackling complex problems or experimenting.

Studies indicate that developers who experience anxiety around code reviews tend to procrastinate or disengage, pointing to higher stress and lower engagement when review workloads are heavy. Reducing bottlenecks improves throughput, restores developer satisfaction, and frees engineers to dedicate time to meaningful, high-impact work.

Signs your team is entering the Code Review Doom Loop

These patterns are common early indicators:

  • PRs often exceed 300 to 500 lines.

  • Reviews regularly take more than 24 hours to begin.

  • Reviewers have multiple open PR tabs at any given time.

  • Senior engineers spend long stretches clearing review queues.

  • Developers ping reviewers for updates on Slack.

  • Many PRs merge in batches at the end of the sprint.

Note: If many of the above patterns look familiar, the loop is already forming.

How to break the code review doom loop?

1. Reduce reviewer load with structured feedback

Concise, organized feedback helps reviewers process PRs faster and more reliably.

2. Make context accessible

Shared context reduces dependency on a few senior engineers.
Lightweight documentation, clear descriptions, and structured summaries make reviews more distributed.

3. Automate code review where possible

AI-assisted review tools that catch repetitive errors, summarize changes, or surface key issues reduce the amount of manual effort required in reviews.

4. Keep PRs small and frequent

Small PRs are reviewed faster, merged faster, and create fewer downstream delays. Teams that normalize small PRs see measurable improvements in review speed.

How AI-assisted reviews help teams escape the loop

AI-assisted review tools support teams by:

  • Summarizing the intent of a PR.

  • Highlighting the most important sections to review.

  • Reducing the time spent re-reading code.

  • Offering consistent feedback across reviewers.

  • Helping reviewers regain context more quickly.

This reduces the time developers spend waiting for feedback and helps teams maintain a steady flow. Teams interested in understanding how AI and manual reviews compare can read more in our detailed breakdown.

Restoring flow in your review process

Code review bottlenecks rarely start as visible issues. They begin as small delays, growing PR sizes, and concentrated review responsibilities. Over time, they affect delivery, predictability, and team satisfaction.

When review load is distributed, context is clear, and reconstruction time is low, teams move with fewer interruptions and less hidden delays. They ship features faster, close feedback loops quicker, and maintain quality without relying on a small group to carry the entire review cycle.

If your team is seeing slowdowns you cannot fully explain, the review workflow is usually the first place to investigate.

Want to understand how your team can speed up reviews without changing your engineering culture? 

Book a demo with cubic and see how structured, AI-assisted reviews fit into your workflow.

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