The "secret" stack behind most YC startups is not a secret. It is the same five tools, over and over.
We tore down the default YC company stack because founders romanticize it. They assume the hot batch is running some exotic tooling edge. They are not. The typical YC startup stack is almost aggressively boring, and that is the point: boring is fast, and on an accelerator clock, fast wins. So here is what is actually in there, what to copy, and where the money quietly leaks out.
◢What is the typical tech stack for a YC startup?
A Next.js or React app on Vercel, Stripe for payments, Linear for issues, Slack for chat, and Notion for docs. That core covers most of what an early company needs, and it is shared across batches because it is the quickest route from idea to shipped product.
The numbers back the cliché. Vercel hosts about 25.6% of YC startup sites, and React appears on roughly 250 of 500 YC company sites. When a quarter of an entire accelerator runs the same host, that is not a coincidence. That is a default.
◢Why everyone runs the same five tools
Because reinventing solved problems is how you lose a batch. YC startups converge on a handful of architectures for a simple reason: these tools get you from zero to a deployed, billable product faster than anything else.
There is a second reason nobody says out loud. Defaults de-risk hiring and debugging. A huge community means more answers on Stack Overflow, more engineers who already know the tool, and fewer hours lost to obscure bugs. When you have not found product-market fit, every hour spent on infrastructure is an hour stolen from the actual product.
◢What to copy, no hesitation
Take the core. Hosting, payments, and issue tracking are solved, and copying the defaults buys you weeks.
Vercel for hosting. It gets a Next.js app from idea to live faster than almost anything, which is why a quarter of YC runs it. We use the same default in our ops recipes.
Stripe for payments. Do not build billing. Wire Stripe and move on.
Linear, Slack, Notion for the workflow. Issues, chat, docs. They have generous free tiers, so an early team can run all three for close to nothing.
This boring core is not where startups overspend. Copy it and spend your real time on the product.
◢Where the YC stack quietly bleeds money
Now the part that matters, because nobody pays us to recommend anything. The core is cheap. The bloat is not. The waste hides in the long tail of tools founders bolt on out of FOMO.
The classic offenders: a second project-management tool nobody agreed to, an analytics platform you set up once and never open, and an enterprise plan bought for a single SSO toggle. The 2025 startup-stack advice is full of "essential" tools that are anything but for a five-person team. Each one looks small. Together they are your biggest controllable burn.
This is exactly the mess a SaaS sprawl audit is built to find, and it usually claws back 20% to 30% of spend without removing anything anyone actually uses.
◢Where copying the YC stack breaks
The defaults are defaults for a reason, but they are not law. The newest YC batches skew heavily toward AI agents and infrastructure, and those teams reach for model providers, vector stores, and orchestration tools the classic stack never included. If you are building in a niche, the boring core still applies, but the edges of your stack will and should look different.
The other failure mode is copying the extras instead of just the core. Cloning another startup's full tool list, peripherals included, is how you inherit their bloat without their revenue. Take the spine, skip the rest.
◢The takeaway
The typical YC stack is a gift: copy the boring core (Vercel, Stripe, Linear, Slack, Notion) and you skip weeks of wheel-reinventing. The discipline is in what you refuse to add. Start lean, resist the FOMO tools, and audit the long tail every quarter, because that creep is where almost every startup overspends.
Want the boring-but-bulletproof stacks turned into recipes you can wire this week, with what to cut spelled out? That is our weekly release. Drop your email and steal the next one.