Devstral 2512

OpenRouter

262K context$0.05/M input$0.22/M output

1324peak 1341

Avg Score

64.2

Avg Cost

$0.03

Score/$

2074.7

Runs

Win/Loss/Draw

Scoring Dimensions

Score Distribution

Category ELOs

debuggingmedium

1537

backendeasy

1520

from-scratchexpert

1505

refactoringexpert

1496

debuggingexpert

1491

multi-languagehard

1455

debugging

1449

refactoring

1399

debugginghard

1390

multi-language

1367

refactoringmedium

1361

full-stackhard

1323

frontendexpert

1307

backendhard

1306

frontend

1288

backend

1287

full-stack

1285

from-scratch

1284

frontendhard

1275

code-reviewmedium

1269

backendexpert

1258

frontendmedium

1249

backendmedium

1224

code-review

1223

frontendeasy

1191

full-stackmedium

1185

from-scratchhard

1183

from-scratchmedium

1148

from-scratcheasy

1143

multi-languageexpert

1115

code-reviewhard

238

All Results

Task	Category	Score	Duration	Cost
Fix hallucination and context window bugs in RAG agent	backend	53.4	59.5s	$0.02
Fix deadlocking transaction patterns in Flask app	backend	72.5	34.2s	$0.01
Build terminal UI dashboard	from-scratch	59.5	1m 7s	$0.02
Debug race condition in worker pool	debugging	87.5	2.8s	<$0.01
Fix memory leak in event handler	debugging	78.2	17.5s	$0.04
Write tests for untested legacy Flask service	code-review	39.1	1m 40s	$0.03
Find and fix 4 hidden backdoors in Flask app	debugging	78.7	25.8s	$0.01
Build MCP server for database management	backend	80.5	28.0s	<$0.01
Build real-time portfolio risk calculator	backend	38.8	1m 44s	$0.03
Add caching layer to eliminate slow SSR page loads	full-stack	77.8	42.2s	$0.03
Build distributed node cluster with gossip protocol	from-scratch	25.6	54.2s	<$0.01
Add streaming SSE endpoint for LLM chat	backend	80.0	46.2s	$0.04
Build materialized view refresh pipeline for analytics	backend	75.8	1m 30s	$0.03
Implement zero-trust API authentication layer	backend	69.3	1m 9s	$0.03
Debug and fix 6 broken database triggers and constraints	debugging	88.0	20.4s	<$0.01
Write Kubernetes manifests for Node.js microservice	full-stack	77.7	18.6s	$0.02
Code review: identify security vulns	code-review	76.0	47.0s	$0.04
Add Google OAuth2 login to Express app	full-stack	72.9	1m 8s	$0.05
Convert React app to PWA with offline support	frontend	65.8	1m 7s	$0.03
Write integration tests for payment flow	code-review	46.3	1m 3s	$0.05
Optimize bloated React bundle under 500KB	frontend	72.0	1m 30s	$0.04
Fix auth bypass vulnerability	debugging	67.5	39.4s	$0.04
Find and patch all OWASP Top 10 vulnerabilities	debugging	69.5	1m 33s	$0.04
Replace console.log with structured logging	refactoring	80.9	44.1s	$0.03
Fix race conditions in order matching engine	backend	72.2	48.9s	$0.02
Add slash commands and moderation to Discord bot	backend	69.0	48.5s	$0.01
Split 1100-line god file into proper modules	refactoring	57.6	1m 8s	$0.03
Add rate limiting middleware	backend	75.0	28.8s	$0.01
Dockerize Node.js monorepo	full-stack	46.5	24.5s	$0.04
Fix Node.js stream backpressure causing OOM on large files	backend	36.0	21.9s	$0.04
Add file upload with S3 presigned URLs	backend	43.5	1m 6s	$0.05
Build RAG pipeline with vector search	backend	46.0	54.4s	$0.01
Fix broken responsive layout	frontend	68.3	31.7s	$0.05
Add retry logic and dead letter queue to Python task queue	backend	60.2	43.0s	$0.02
Add WebSocket real-time updates	full-stack	75.7	27.0s	$0.04
Build SaaS admin dashboard from scratch	from-scratch	49.9	3m 7s	$0.05
Add Redis caching layer to Express API	backend	54.9	1m 51s	$0.06
Migrate callback-hell Express app to async/await	refactoring	59.4	1m 6s	$0.05
Add cursor-based pagination to REST API	backend	67.3	32.7s	$0.04
Fix N+1 query in dashboard	backend	47.4	30.7s	<$0.01
Write complex SQL report with window functions	backend	59.5	2m 44s	$0.04
Port Python CLI to Rust	multi-language	47.1	32.5s	$0.01
Implement transformer inference engine with KV cache	from-scratch	76.7	25.6s	<$0.01
Build codebase indexer for LLM context windows	from-scratch	47.1	1m 8s	$0.03
Fix React hydration mismatch	frontend	52.5	24.8s	$0.04
Implement multi-tenant row-level security in Postgres	backend	57.5	1m 1s	$0.03
Fix data integrity bugs in denormalized e-commerce schema	debugging	75.2	46.7s	$0.02
Build CLI tool with subcommands and config	from-scratch	61.4	1m 21s	$0.03
Harden insecure Docker setup with 12 vulnerabilities	code-review	74.0	21.0s	$0.02
Build REST API from scratch	from-scratch	72.8	25.5s	<$0.01
Fix broken GitHub Actions CI pipeline	debugging	92.0	10.5s	$0.02
Optimize slow Postgres queries in Flask app	backend	65.0	31.5s	$0.01
Add i18n with locale routing to Next.js app	full-stack	67.5	2m 4s	$0.04
Fix 12 WCAG accessibility violations in checkout form	frontend	75.0	1m 24s	$0.05
Remove AI slop and over-engineering from codebase	refactoring	74.0	39.6s	$0.02
Implement Stripe webhook handler	backend	47.9	41.2s	$0.04
Implement JWT auth middleware	backend	64.4	1m 14s	$0.24
Build production website with auth and members area	frontend	63.3	6m 21s	$0.06
Build LLM evaluation harness with structured grading	backend	46.0	2m 7s	$0.03
Implement background job scheduler with persistence	backend	59.1	1m 27s	$0.02
Add GraphQL layer over REST API	multi-language	73.7	34.3s	$0.01
Add virtual scrolling to table rendering 5000 rows	frontend	65.8	22.0s	<$0.01
Zero-downtime schema migration	full-stack	57.0	11.3s	<$0.01
Fix flaky test suite	debugging	69.8	16.1s	<$0.01
Refactor monolithic handler to CQRS	refactoring	66.5	21.5s	<$0.01