Agent leaderboards / All sectors / Serverless functions
Serverless functions: which platforms coding agents choose
AWS Lambda took about 24% of runs, Vercel Functions about 23%.
Read this leaderboard as textrankings, key learnings, method
Key learnings
We asked three coding agents to add serverless functions to eight small apps. That ran 287 times, worded several ways and asked as four kinds of user. Under the two leaders the picks scattered, and 50 times the agents wrote the functions themselves.
Who was asking moved the answer
For enterprise teams the pick was Azure Functions, 36 times out of 72 runs. Vibe coders got Cloudflare Workers most often. Junior developers got Vercel Functions in 34 of their 72 runs.
Wording alone changed most answers
Each agent got the same job on the same app more than once, in different words. In 16 of those 24 groups of runs, the answer wasn't always the same platform.
One agent went to Lambda far more
Codex picked AWS Lambda in 49 of its 96 runs. Cursor and Claude Code both put Vercel Functions on top instead.
- The simulated user approved every plan, but sent the agent back at least once in 29 runs.
- In nine runs it refused to approve until the agent named a specific platform.
- All five wins for Render came in one helpdesk billing starter codebase.
- All four wins for Fly.io came in a Remix workshop bookings app.
- Google Cloud Run won 11 runs, ahead of the rest of the smaller platforms.
The ranking287 runs
| Product | Wins | Share | ||
|---|---|---|---|---|
| 1 | AWS Lambdaaws.amazon.com | 70 | 24% | |
| 2 | Vercel Functionsvercel.com | 65 | 23% | |
| 3 | Built in-houseoutcome | 50 | 17% | |
| 4 | Azure Functionsazure.microsoft.com | 36 | 13% | |
| 5 | Cloudflare Workersworkers.cloudflare.com | 20 | 7% | |
| 6 | Google Cloud Runcloud.google.com | 11 | 4% | |
| 7 | Inngestinngest.com | 7 | 2% | |
| 8 | Renderrender.com | 5 | 2% | |
| 9 | Fly.iofly.io | 4 | 1% | |
| 10 | Google Cloud Functionscloud.google.com | 2 | 1% | |
| 11 | Inngest + Vercel Functions | 1 | 0% | |
| 12 | Trigger.devtrigger.dev | 1 | 0% | |
| 13 | Upstash QStashupstash.com | 1 | 0% | |
| 14 | Netlify Functionsnetlify.com | 1 | 0% |
By agent, by persona, by wording
By agent
| Codex · GPT-5.6 Sol96 runs | AWS Lambda · 49then Vercel Functions · 20 |
| Claude Code · Claude Opus 596 runs | Vercel Functions · 24then Azure Functions · 12 |
| Cursor · Grok 4.695 runs | Vercel Functions · 21then AWS Lambda · 18 |
By persona
| Senior engineer107 runs | AWS Lambda · 36then Vercel Functions · 31 |
| Enterprise team72 runs | Azure Functions · 36then AWS Lambda · 21 |
| Junior developer72 runs | Vercel Functions · 34then AWS Lambda · 10 |
| Vibe coder36 runs | Cloudflare Workers · 15then Fly.io · 4 |
By what the ask stressed
| The plain ask287 runs | AWS Lambda · 70then Vercel Functions · 65 |
A case is one codebase with one agent, asked several times in different words and as different people. 16 of 24 cases did not hold to a single platform.
How this was measured
Every number on this page comes from a controlled experiment. We took 8 small applications, asked 3 coding agents (Codex (GPT-5.6 Sol), Claude Code (Claude Opus 5), Cursor (Grok 4.6)) to add serverless functions to each of them, in several wordings and as a senior engineer and enterprise team and junior developer and vibe coder, and let the agent choose the product. Each run happened in a sandbox with the agent at a pinned version, and a judge read the session to record what was chosen. That is 287 runs. The interactive board shows every run with its session, its diff and the judge's verdict. A simulated user stood in for the owner of the codebase: it read the agent's plan and had to approve it before any code was written; it sent the agent back at least once in 29 runs. Read the methodology and the publications.
If you sell in this sector: what these numbers mean for a vendor.
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