01 / EDITOR + AGENT
Cursor — where you actually work
A VS Code fork with an agent that lives inside your repo. Composer edits multiple files in one pass; background agents run in the cloud and open pull requests from a conversation.
Why it wins: lowest learning curve of any agent editor, the best autocomplete in the category, and the multi-file edit flow that other editors are still copying. Offload heavy refactors to Claude Code or Codex when you need them — but Cursor is the daily driver.
02 / HOSTING + AI INFRASTRUCTURE
Vercel — the platform under everything
Push to GitHub, get a preview URL in seconds. Fluid Compute is the default runtime — Node.js 24 LTS, 300-second timeouts, Active CPU pricing that only charges for time your code is actually running.
Why it wins: nothing else gets you from git push to a shareable URL faster, and the AI Gateway turns multi-provider model wiring into one environment variable. Auth, blob storage, KV-replacement, observability — all native, all code-configurable.
03 / MODEL
Anthropic Claude — the brain
Sonnet 4.6 is the default for app development: 1M-token context, $3 / $15 per million tokens, the best speed/intelligence tradeoff Anthropic ships. Reach for Opus 4.7 on hard reasoning and agentic work; drop to Haiku 4.5 for high-volume cheap calls.
Why it wins: Claude is the model the rest of the stack is tuned for. Cursor uses it. Claude Code uses it. The AI SDK has first-class support. You're not betting on a model — you're betting on the model the tools are already built around.
04 / DATABASE
Neon — Postgres via Vercel Marketplace
Serverless Postgres with branching — every pull request gets its own database branch you can blow away. Autoscaling, point-in-time recovery, a serverless driver designed for edge runtimes, and a single Vercel invoice.
Why it wins: Vercel Postgres and Vercel KV are deprecated; Neon is the path. Branch-per-PR is the killer feature once you've used it — your migrations get a fresh database every time, and merging the PR merges the schema.
05 / SOURCE CONTROL
GitHub — the source of truth
Your repo is what the rest of the stack listens to. Push a commit and Vercel builds, Cursor's background agents open PRs from Slack, code review happens in pull requests, and the deploy is just a merge.
Why it wins: every other tool in the stack treats GitHub as the spine. Going around it (GitLab, raw FTP, dashboard uploads) breaks the loop. Stay with the spine.
06 / WHEN YOU NEED IT
Railway — for the workloads Vercel won't run
A worker, a cron job, a queue consumer, a long-running websocket server — anything Fluid Compute's request/response model doesn't fit. Railway gives you those alongside your app under one bill, with predictable plan-based pricing.
Why it wins (when it does): Vercel handles 90% of what most apps need. For the other 10% — multi-service orchestration, a Python ML worker, a Discord bot, a Telegram poller — Railway is the cleanest place to put it.