Use Case

Automated Performance Code Review

Catch N+1 queries, memory leaks, and performance anti-patterns before they reach production. Save infrastructure costs. Works great with code quality checks.

10x
Cheaper than production fixes
N+1
Query detection accuracy
8+
ORMs supported
Pre-merge
Issues caught

Performance Issues Are Silent Killers

Slow code costs money, frustrates users, and compounds over time. Track it alongside technical debt for full visibility.

Performance Issues Found Too Late

88% of performance issues are discovered in production. Fixing them post-release is 10x harder and costs 100x more than catching at code review.

Expensive Infrastructure Scaling

Teams overspend $50-200k/year on infrastructure to compensate for inefficient code. A single N+1 query can cost $10k/month in database load.

Code Reviewers Miss Performance Issues

Only 15% of N+1 queries are caught in code review. Reviewers focus on correctness — memory leaks and O(n²) algorithms slip through 85% of the time.

Performance Regressions Accumulate

Average app slows 23% per year from accumulated inefficiencies. Users abandon pages that take >3 seconds. 1 second delay = 7% conversion drop.

Performance Issues We Detect

From database queries to frontend rendering — we catch it all

Critical

N+1 Queries

Database queries inside loops that should be batched

Loop with 100 iterations = 100 queries → 1 query
Critical

Memory Leaks

Unreleased resources, growing collections, event listeners

Event listener attached but never removed
High

Expensive Loops

O(n²) algorithms when O(n) is possible

Nested loops over large arrays
High

Blocking Operations

Synchronous I/O that should be async

fs.readFileSync in request handler
Medium

Unnecessary Re-renders

React components re-rendering without memo

Parent state change re-renders all children
Medium

Large Bundle Imports

Importing entire libraries when tree-shaking available

import _ from 'lodash' vs import get from 'lodash/get'
Database Intelligence

N+1 Query Detection for Your ORM

diffray understands popular ORMs and detects N+1 queries, missing eager loading, and inefficient query patterns specific to your stack.

Before vs After diffray

Before

// 100 users = 101 queries

users.forEach(user => user.posts)

// 2000ms response time

After diffray

// 100 users = 2 queries

users.include(:posts).each...

// 50ms response time

Framework-Specific Analysis

Performance rules tailored to your tech stack

React

Frontend
  • Re-renders
  • Memoization
  • Bundle size
React Rendering

Next.js

Fullstack
  • Server components
  • Data fetching
  • ISR/SSG
Next.js Optimizing

Node.js

Backend
  • Event loop blocking
  • Memory leaks
  • Streams
Event Loop Guide

Express

Backend
  • Middleware order
  • Async handlers
  • Response times
Express Performance

How Performance Review Works

Catch performance issues before they reach production

1

PR with Code Changes

Developer creates a pull request with new code

2

Performance Analysis

AI analyzes code for performance anti-patterns

3

Impact Assessment

Each issue includes severity and estimated impact

4

Fix Suggestions

Get specific code changes to fix each issue

Teams That Ship Fast Code

"diffray found 47 N+1 queries in our first week. Our API response times dropped from 2s to 200ms."

M

Michael Torres

Backend Lead, E-commerce Platform

"We reduced our AWS bill by 40% after fixing the performance issues diffray identified. It paid for itself in week one."

L

Lisa Chen

VP Engineering, Growth Startup

Frequently Asked Questions

What performance issues does diffray detect?

diffray detects N+1 queries, memory leaks, expensive loops, inefficient algorithms (O(n²) when O(n) is possible), missing indexes, synchronous operations that should be async, and resource-intensive operations in hot paths.

How is this different from runtime profiling?

Runtime profiling shows issues after they happen. diffray catches performance problems at code review time, before the code is merged. This prevents performance regressions from ever reaching production.

Does diffray understand my ORM and database?

Yes. diffray understands popular ORMs like Prisma, TypeORM, Sequelize, ActiveRecord, and Django ORM. It detects N+1 queries, missing eager loading, and inefficient query patterns specific to your ORM.

Can diffray detect frontend performance issues?

Yes. diffray detects React re-render issues, missing memoization, large bundle imports, inefficient CSS selectors, and other frontend performance anti-patterns.

How does diffray calculate the impact of performance issues?

diffray analyzes code paths to estimate impact. For N+1 queries, it calculates potential query count based on typical data volumes. For algorithms, it identifies Big O complexity. Each finding includes severity and estimated performance impact.

Can diffray help reduce infrastructure costs?

Absolutely. Teams typically see 20-40% infrastructure cost reduction after fixing issues diffray identifies. By catching inefficient code before production, you avoid scaling problems that require throwing more servers at slow code.

Related Use Cases

Ship Faster Code, Not Slower

Get automated performance review on every PR. Free for 14 days, no credit card required.

N+1 query detection
Memory leak analysis
8+ ORMs supported