Summarize with AI
A Next.js development agency builds your website or web app in Next.js and React, then hands over a repository your own engineers can keep working in. A good one ships something that loads fast, renders on the server, and does not need them again. A weak one hands you a codebase nobody wants to open.
If your team already writes React, the question is not whether you could build it yourselves. It is whether three months of engineering time belongs in a marketing site. Here is what these agencies actually do, the checks that separate them, and when a simpler platform is the better answer.
The three kinds of work, and why the difference matters
Most Next.js engagements are one of three shapes. A marketing site, where the real work is design, content structure, and page speed. A product surface such as a dashboard or a customer portal, where the work is state, data, and edge cases. Or a migration, where an existing site moves onto Next.js from WordPress, Webflow, or a framework the team has outgrown.
These need different people. A studio that is excellent at marketing pages may never have shipped an authenticated dashboard. Ask which of the three they do most often, then ask for two examples of that exact shape. Not their best work. That shape.
Why teams that can code still hire out
Engineer-led teams usually hire for one of two reasons. Either nobody wants to own the marketing site, or the site keeps losing to design decisions nobody on the team is qualified to make.
The second reason is the expensive one. A strong engineering team can ship a technically perfect site that fails to explain the product. When that is the problem, you are really buying design and copy structure, and the code is just how it gets delivered. Be honest about which one you are buying, because it changes the entire shortlist.
Open a site they built and read the source
This is the fastest check and almost nobody does it. Load a site the agency built, view the page source, and look for the actual copy in the HTML. If the page arrives as an empty container and fills in from JavaScript afterwards, they have shipped a client-side app wearing a Next.js label. Search engines and AI crawlers will treat it that way.
While you are there, run the page through Lighthouse or PageSpeed Insights. You are not looking for a perfect score. You are looking for whether anyone was paying attention.
Ask how they decided what renders where
Next.js gives you static pages, server rendered pages, and client components, and the choice is a real decision with real consequences. Ask which pages on a past project are static, which are server rendered, and why they split them that way.
A studio that has thought about this will answer in plain sentences. A studio that copied a starter template will answer with product names. The answer tells you whether you are hiring engineers or assemblers.
Look at a repository before you sign
Ask to see a real client repository with the sensitive parts removed. You are checking three things. Whether components get reused or copied. Whether anything is tested. And whether the commit history reads like work happening over weeks or like one enormous upload at the end.
The last one matters more than it sounds. A single giant commit usually means the client never saw the work in progress, which usually means the client had no way to redirect it.
Find out who will own the hosting and the accounts
Vercel is the default host for Next.js and there is nothing wrong with that. What matters is whose account it sits in. If the project lives in the agency's Vercel team, their analytics, and their domain registrar, you are renting your own website and the rent is not written down anywhere.
Ask for everything to be created in your accounts from day one, with the agency invited as a member. Any agency that resists this is telling you how the relationship ends.
Decide who edits the site after launch
This is where Next.js builds most often go wrong for small teams. The site ships, marketing wants to change a headline, and the only path is a pull request. Six months later the site is stale because editing it costs an engineer an afternoon.
Ask what the editing story is before you start. Usually that means a headless CMS with the content modelled properly, so a non-engineer can publish without touching the repository. If the answer is that you will just ask them, that is a retainer, and it should be priced as one.
What it costs and how long it takes
Most agencies do not publish Next.js pricing, because scope varies enormously between a five page marketing site and a data-heavy product surface. Where studios do publish, custom builds start meaningfully above template-based work, and marketing sites commonly run four to eight weeks depending on how much content is ready.
The variable that moves the timeline most is not code. It is copy. Projects stall while somebody decides what the product actually claims. If you have that written before you start, you will finish near the estimate.
When Next.js is the wrong choice
If the site is a handful of marketing pages that your team will want to edit weekly, custom code is usually the slower and more expensive answer. A visual platform gets you there faster and keeps you independent. We wrote a longer comparison in Webflow vs Next.js for marketing sites, and the short version is that most companies should run both: a visual platform for marketing, Next.js for the product.
Choose Next.js when the site and the product genuinely share components, when you need rendering control a platform will not give you, or when your engineers will be in the codebase anyway.
Where to start
If you want a shortlist rather than more reading, we keep one for custom code website development agencies working with AI startups, compared on platform depth, team shape, and what each one publishes about price.
Studio Maydit builds in Framer, Webflow, and custom code, and works with AI founders across the US, UK, and Europe. If you want a second opinion on whether your site belongs in Next.js at all, book a free 30-minute call.
Picking the stack and picking the company that builds on it are two decisions, and the second one has its own checks: who owns the repository at the end, how the marketing site and the product get split, and what handover actually looks like. Those are covered in hiring an AI web development company.
