Qwen3.5 Plus 02.15

OpenRouter

1000K context$0.40/M input$2.40/M output

1509

Avg Score

70.6

Avg Cost

$0.13

Score/$

553.4

Runs

123

Win/Loss/Draw

Scoring Dimensions

Score Distribution

Category ELOs

multi-languageexpert

2538

code-reviewhard

2293

from-scratchmedium

2200

refactoringexpert

1878

from-scratchexpert

1814

frontendhard

1672

code-review

1584

backendhard

1575

refactoring

1571

from-scratch

1558

frontendeasy

1551

multi-language

1548

refactoringmedium

1545

full-stackmedium

1544

backendexpert

1539

full-stack

1538

full-stackhard

1534

from-scratchhard

1514

backend

1512

code-reviewmedium

1502

debuggingmedium

1488

backendmedium

1478

frontend

1445

frontendmedium

1438

from-scratcheasy

1435

debugginghard

1419

debugging

1413

debuggingexpert

1382

backendeasy

1203

frontendexpert

1165

multi-languagehard

1136

All Results

Task	Category	Score	Duration	Cost
Build CLI tool with subcommands and config	from-scratch	73.1	12m 26s	$1.49
Build CLI tool with subcommands and config	from-scratch	75.5	11m 51s	$1.04
Write integration tests for payment flow	code-review	83.8	14m 37s	$0.42
Build distributed node cluster with gossip protocol	from-scratch	75.0	5m 52s	$0.33
Fix hallucination and context window bugs in RAG agent	backend	83.3	2m 50s	$0.13
Build real-time portfolio risk calculator	backend	81.7	7m 6s	$0.38
Port Python CLI to Rust	multi-language	76.2	4m 21s	$0.12
Code review: identify security vulns	code-review	75.9	1m 5s	$0.02
Implement background job scheduler with persistence	backend	69.5	2m 23s	$0.03
Add i18n with locale routing to Next.js app	full-stack	62.5	9m 30s	$0.05
Fix broken GitHub Actions CI pipeline	debugging	62.4	1m 43s	$0.04
Build terminal UI dashboard	from-scratch	74.3	2m 35s	$0.03
Add streaming SSE endpoint for LLM chat	backend	70.8	4m 23s	$0.05
Fix broken responsive layout	frontend	72.8	2m 28s	$0.05
Write complex SQL report with window functions	backend	85.7	2m 51s	$0.04
Write tests for untested legacy Flask service	code-review	65.0	7m 38s	$0.09
Find and patch all OWASP Top 10 vulnerabilities	debugging	65.8	5m 44s	$0.04
Add virtual scrolling to table rendering 5000 rows	frontend	80.0	2m 53s	$0.05
Fix flaky test suite	debugging	90.9	32.9s	<$0.01
Dockerize Node.js monorepo	full-stack	75.1	2m 53s	$0.03
Add Google OAuth2 login to Express app	full-stack	75.8	4m 52s	$0.05
Fix auth bypass vulnerability	debugging	76.8	3m 17s	$0.04
Build REST API from scratch	from-scratch	78.3	43.6s	<$0.01
Implement Stripe webhook handler	backend	76.3	1m 33s	$0.04
Optimize bloated React bundle under 500KB	frontend	69.6	6m 53s	$0.04
Build RAG pipeline with vector search	backend	50.9	3m 14s	$0.03
Fix 12 WCAG accessibility violations in checkout form	frontend	80.7	5m 52s	$0.07
Refactor monolithic handler to CQRS	refactoring	60.8	5m 14s	$0.06
Add WebSocket real-time updates	full-stack	85.6	31.3s	$0.02
Fix N+1 query in dashboard	backend	83.3	39.4s	<$0.01
Find and fix 4 hidden backdoors in Flask app	debugging	87.0	32.9s	<$0.01
Fix Node.js stream backpressure causing OOM on large files	backend	65.3	1m 56s	$0.04
Build materialized view refresh pipeline for analytics	backend	85.6	2m 25s	$0.03
Build LLM evaluation harness with structured grading	backend	52.5	3m 44s	$0.05
Optimize slow Postgres queries in Flask app	backend	77.7	1m 16s	$0.02
Add file upload with S3 presigned URLs	backend	74.1	2m 38s	$0.05
Debug race condition in worker pool	debugging	82.3	12.4s	<$0.01
Build SaaS admin dashboard from scratch	from-scratch	44.3	5m 24s	$0.07
Fix memory leak in event handler	debugging	49.3	1m 7s	$0.04
Build production website with auth and members area	frontend	60.5	13m 17s	$0.14
Add rate limiting middleware	backend	66.3	1m 6s	$0.02
Fix deadlocking transaction patterns in Flask app	backend	83.1	1m 28s	$0.02
Implement zero-trust API authentication layer	backend	74.1	7m 7s	$0.05
Migrate callback-hell Express app to async/await	refactoring	74.1	5m 2s	$0.03
Split 1100-line god file into proper modules	refactoring	74.8	5m 55s	$0.04
Replace console.log with structured logging	refactoring	55.5	5m 21s	$0.06
Add cursor-based pagination to REST API	backend	46.6	3m 4s	$0.04
Fix React hydration mismatch	frontend	53.9	2m 3s	$0.04
Harden insecure Docker setup with 12 vulnerabilities	code-review	79.0	2m 56s	$0.03
Add slash commands and moderation to Discord bot	backend	65.8	2m 21s	$0.03
Convert React app to PWA with offline support	frontend	77.3	4m 56s	$0.04
Implement multi-tenant row-level security in Postgres	backend	45.5	11m 23s	$0.07
Debug and fix 6 broken database triggers and constraints	debugging	65.1	3m 43s	$0.05
Write Kubernetes manifests for Node.js microservice	full-stack	82.6	39.7s	$0.02
Build MCP server for database management	backend	78.5	1m 42s	$0.03
Add Redis caching layer to Express API	backend	53.9	6m 17s	$0.05
Fix data integrity bugs in denormalized e-commerce schema	debugging	81.7	1m 47s	$0.03
Add retry logic and dead letter queue to Python task queue	backend	79.7	1m 27s	$0.02
Implement transformer inference engine with KV cache	from-scratch	81.7	35.7s	<$0.01
Remove AI slop and over-engineering from codebase	refactoring	85.0	4m 5s	$0.02
Implement JWT auth middleware	backend	55.0	3m 41s	$0.04
Add GraphQL layer over REST API	multi-language	53.6	4m 10s	$0.04
Add caching layer to eliminate slow SSR page loads	full-stack	82.7	3m 21s	$0.03
Build codebase indexer for LLM context windows	from-scratch	46.0	3m 25s	$0.04
Fix race conditions in order matching engine	backend	79.5	2m 58s	$0.04
Zero-downtime schema migration	full-stack	72.6	36.4s	<$0.01
Split 1100-line god file into proper modules	refactoring	67.9	5m 10s	$1.06
Remove AI slop and over-engineering from codebase	refactoring	84.6	1m 57s	$0.42
Fix broken responsive layout	frontend	78.0	2m 18s	$0.20
Implement JWT auth middleware	backend	87.9	57.9s	$0.08
Convert React app to PWA with offline support	frontend	67.5	4m 60s	$0.56
Implement multi-tenant row-level security in Postgres	backend	82.3	3m 47s	$0.65
Harden insecure Docker setup with 12 vulnerabilities	code-review	85.4	37.6s	$0.03
Add caching layer to eliminate slow SSR page loads	full-stack	83.2	3m 51s	$0.54
Optimize bloated React bundle under 500KB	frontend	67.1	5m 19s	$0.93
Implement zero-trust API authentication layer	backend	71.1	5m 1s	$0.81
Dockerize Node.js monorepo	full-stack	81.6	47.4s	$0.07
Find and patch all OWASP Top 10 vulnerabilities	debugging	72.1	4m 58s	$0.73
Replace console.log with structured logging	refactoring	53.5	7m 1s	$0.96
Add i18n with locale routing to Next.js app	full-stack	67.7	5m 50s	$0.84
Build codebase indexer for LLM context windows	from-scratch	44.4	6m 8s	$1.08
Write Kubernetes manifests for Node.js microservice	full-stack	91.3	56.9s	$0.10
Build production website with auth and members area	frontend	67.3	2m 13s	$0.03
Build SaaS admin dashboard from scratch	from-scratch	67.7	1m 56s	$0.03
Implement background job scheduler with persistence	backend	56.1	1m 43s	$0.02
Build MCP server for database management	backend	83.0	31.9s	<$0.01
Implement transformer inference engine with KV cache	from-scratch	51.5	37.0s	<$0.01
Build CLI tool with subcommands and config	from-scratch	68.3	1m 29s	$0.02
Fix hallucination and context window bugs in RAG agent	backend	71.5	1m 16s	$0.02
Build real-time portfolio risk calculator	backend	59.1	1m 25s	$0.03
Build LLM evaluation harness with structured grading	backend	48.0	42.6s	$0.01
Build materialized view refresh pipeline for analytics	backend	66.5	1m 35s	$0.03
Fix race conditions in order matching engine	backend	70.7	33.2s	$0.01
Fix data integrity bugs in denormalized e-commerce schema	debugging	68.5	1m 5s	$0.02
Write complex SQL report with window functions	backend	69.7	52.4s	$0.02
Debug and fix 6 broken database triggers and constraints	debugging	79.5	29.4s	<$0.01
Fix deadlocking transaction patterns in Flask app	backend	66.8	31.4s	$0.01
Find and fix 4 hidden backdoors in Flask app	debugging	93.3	19.9s	<$0.01
Add Redis caching layer to Express API	backend	74.9	43.2s	$0.01
Write tests for untested legacy Flask service	code-review	69.5	1m 43s	$0.03
Optimize slow Postgres queries in Flask app	backend	80.2	21.2s	<$0.01
Add slash commands and moderation to Discord bot	backend	72.4	29.9s	<$0.01
Fix 12 WCAG accessibility violations in checkout form	frontend	81.0	1m 12s	$0.02
Add retry logic and dead letter queue to Python task queue	backend	72.5	15.8s	<$0.01
Add virtual scrolling to table rendering 5000 rows	frontend	69.0	15.1s	<$0.01
Fix Node.js stream backpressure causing OOM on large files	backend	74.7	6.4s	<$0.01
Build distributed node cluster with gossip protocol	from-scratch	66.0	21.6s	<$0.01
Fix auth bypass vulnerability	debugging	84.0	9.2s	<$0.01
Write integration tests for payment flow	code-review	44.6	28.5s	$0.01
Add GraphQL layer over REST API	multi-language	67.2	15.2s	<$0.01
Add rate limiting middleware	backend	65.6	15.6s	<$0.01
Implement Stripe webhook handler	backend	44.6	10.5s	<$0.01
Zero-downtime schema migration	full-stack	61.0	6.2s	<$0.01
Fix flaky test suite	debugging	64.5	8.7s	<$0.01
Refactor monolithic handler to CQRS	refactoring	73.5	19.5s	<$0.01
Add cursor-based pagination to REST API	backend	62.4	10.1s	<$0.01
Code review: identify security vulns	code-review	74.9	21.4s	<$0.01
Fix N+1 query in dashboard	backend	74.5	9.0s	<$0.01
Fix memory leak in event handler	debugging	58.8	5.3s	<$0.01
Debug race condition in worker pool	debugging	86.9	3.4s	<$0.01
Build terminal UI dashboard	from-scratch	54.3	22.5s	<$0.01
Fix React hydration mismatch	frontend	73.5	4.9s	<$0.01
Build REST API from scratch	from-scratch	85.6	7.4s	<$0.01