3600億トークン、300万顧客、6人のエンジニア

Impact at a glance

Durable ships new production agents to customers in a single day

AI features and agents serve ~1.1B tokens per day (360B per year)

10x leverage for every engineer, product manager, and designer

3-4x lower infra cost compared to self hosting

Durable began with a simple goal: make owning a business easier than having a job.

60% of U.S. adults say they want to be their own boss, but only about 4% actually do it. Durable’s bet is that the blocker isn’t ambition. It’s friction. “Small businesses are death by a thousand tools, logins, workflows, and designs,” explained James Clift, founder of Durable. “If you remove those barriers, business owners can focus on their customers.”

Today, Durable is an AI business builder that helps entrepreneurs launch in minutes, then optimize with agents that handle things like SEO, content, and operations. The gap between idea and ownership has never been smaller.

It feels like one seamless experience to their customers, but under the hood it’s a multi-tenant, multi-product platform that has to run millions of individual businesses safely, reliably, and cost-effectively.

As they scaled, manually operating multiple services just to self-host was enough work to be a second product.

With a small team, Durable chose rapid consolidation over incremental improvement: one codebase, one infrastructure platform.

Infra is hard; multi-tenant infra is harder

Durable isn’t serving one app. They are managing millions of customer sites, CRMs, and agents, each with different traffic patterns and different operational needs.

One customer site might get 100x the traffic of another, and power laws show up quickly. When spikes happen, a small portion of Durable customers can consume a disproportionate share of compute, which made cost isolation, attribution, and pricing strategy significant engineering problems.

Khan called out a few of the most acute pain-points from self-hosting:

Custom domains and SSL at SaaS scale, including paying thousands of dollars for SSL termination for custom domains

Multi-region cluster maintenance, which previously required infrastructure engineers to keep clusters running across multiple geographies

Security and bot protection as a multi-tenant risk, so that DDoS attacks aimed at one customer don’t degrade the performance of other sites

Observability and cost attribution across millions of tenants

From AI as plumbing to AI as product

Durable offers more than sites. They help their customers run businesses with a multi-agent, multi-model, multi-modal product.

Once agents became a core part of their platform, their developers ran into three problems that were fundamentally different from self-hosting a website platform:

Model orchestration: They needed to switch models and providers quickly for reliability and cost, without getting locked into long contracts or reworking the system every time there was an outage or a new model release.

Tenant isolation: In a multi-tenant agent system, “context spilling” is existential. Durable needed strict guardrails so one business’s context could never leak into another’s workflows.

Per-customer AI economics: AI workloads vary wildly, so Durable needed customer-level visibility into runs, models, and spend to support usage-based or outcome-based pricing with real fidelity.

Managing self-hosting and AI infrastructure was a massive distraction for Khan's team of six, so he chose to consolidate their platform into a single system designed for multi-tenant AI workloads.

The migration, and why it worked

The team realized their existing stack was limiting their ability to solve their customer and platform problems quickly. They knew that in order to win, they needed to tackle those, and future challenges, faster than the competition. “We’re an AI native application,” Khan explained, “so we must focus on creating value with agents, not building out AWS infrastructure.”

Khan said that the simplicity of Vercel made their app migration possible. He described the infrastructure upgrade as a single, decisive swing they implemented before touching their code: "We skinned the old product using an iframe, pushed to production on Vercel, then ripped out the self-hosted infrastructure entirely."

They didn’t refactor the old way. With a lean team, Durable used coding agents to accelerate the rewrite, burning tokens to move faster as models improved, ultimately emerging with a production-quality codebase.

“Everyone tells you not to rewrite your product,” said Khan, “but we did exactly that, and it worked.”

Even though resource constraints weren't the motivation for the move, their new infrastructure turned out to be far more cost-efficient as well.

Today, Durable’s entire stack runs on Vercel, and they can ship new agents to their customers in a single day.

Area of stack

What Durable uses on Vercel

Build, ship, and run the app

Next.js, Functions, Fluid Compute, Turborepo, Flags, Toolbar

AI + agents

Durable Agents, AI SDK, AI Gateway, Workflows, Skills

Edge delivery + multi-tenant routing

CDN, Domains (API), Cron

Security + abuse prevention

Firewall, Bot Protection, BotID, Sandbox

Observability + performance

Analytics, Speed Insights, OpenTelemetry

Data + output

Blob (public & private assets), Streamdown, json-renderer

10x leverage to support more entrepreneurs

Durable serves more than 3 million businesses. “Think about a 19-year-old selling chocolate-covered bananas at fairs, a holiday porch decoration business in Texas, a plumber who just got their license, and a tech exec who just got laid off,” said Khan. “Those are all Durable customers who are rejecting the 9-5 and building their own future as entrepreneurs.”

That’s impressive for 6 engineers and no DevOps team. James Clift, founder of Durable, feels like they've gotten 100x leverage running on Vercel.

"It’s incredible what we’ve shipped with such a lean team," Clift reflected. "This is how every tech company in the future will operate."

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