Customer story

How Flatfile Upgraded Their Developer Experience With Mintlify

Flatfile's Head of Product Engineering, Ashley Mulligan, shares how their documentation is key to attracting and keeping happy customers.


Smart APIs for file-based data import

Backed by

Tiger Global, Gradient Ventures, Scale Ventures, Workday Ventures, Afore Capital, and Two Sigma Ventures, and investments from founding executives and leadership from Airtable, DocuSign, LinkedIn, and Gainsight.

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Flatfile is an API-first platform that allows developers to collect, clean, validate, and convert data seamlessly. With Flatfile, developers don't have to build their own data import solutions or spend hours on manual database validations.

Developers choose Flatfile to save time. That's why making sure they can easily find the answers they need in Flatfile's docs is a priority for the company. “Developer documentation plays a pivotal role in growth and our ability to run our business,” says Ashley Mulligan, Flatfile's Head of Product Engineering.

The hunt for a new documentation partner

Ashley leads writing and updating docs for Flatfile, a Series B startup with about 70 employees. With its previous documentation solution, The Flatfile team was constantly modifying the design of its docs to meet the company's high design and UX standards.

Styling markdown with Custom CSS isn't that hard, but it's time consuming,” she says. “And trying to get everything to match isn't how you want to spend your time.”

So when Flatfile relaunched its product in the summer of 2023—eliminating low and no-code options to lean into a library of file-based data import APIs—it decided to upgrade to a new documentation provider.

Flatfile had two main requirements: high-quality design and robust built-in features and components. The company sought the flexibility and customization of in-house documentation without the time-consuming process. Mintlify stood out right away, Ashley says.

Mintlify was the only option that checked all the boxes. To get the look, feel, and features we wanted for our documentation, it had to be homegrown or Mintlify.
Ashley Mulligan, Head of Product Engineering

Well-organized docs and supercharged search

Flatfile's relaunch meant it didn't need to import any docs to Mintlify. Getting up and running was as simple as cloning a starter repo and pushing to Git. Although Mintlify offers plenty of options for customization, Ashley only had to make a few simple adjustments to give the docs the look and feel Flatfile wanted.

We added a background image and our light and dark color modes. We're using everything else out of the box. We even matched our in-guide imagery to fit into the Mintlify style.
Ashley Mulligan, Head of Product Engineering

Mintlify's prebuilt UI allowed Flatfile to quickly create organized docs for a smooth developer experience.

“The left sidebar and the nested nature of the sidebar are really clean,” says Ashley. “And the top nav allows you to build microsites within Mintlify. So when I click on a top nav item, I have a whole new sidebar for that area, which gives us a lot of lanes to put content in and separate things.”

Mintlify's ChatGPT-powered search enhances the developer experience by offering relevant context, code snippets, and sources, enabling developers to swiftly find precisely what they need

The AI answers questions beyond what we've written in the documentation and we write our docs in a way to inform ChatGPT. Other developers have asked us how we added AI-powered search because they want to add it to their own docs.
Ashley Mulligan, Head of Product Engineering

Scaling documentation for the future

Mintlify allows Flatfile's documentation to be viewed on mobile devices, which is great for building interest with people who are casually browsing, says Ashley.

It's a growth unlock when somebody on their phone finds Flatfile and is able to see our docs. Whether or not they're doing any work, when people see our docs, they form an opinion about us. So having our docs display so nicely on mobile because of Mintlify is so valuable.
Ashley Mulligan, Head of Product Engineering

Ashley has started to have others authoring and updating docs with Mintlify.

“I've begun an initiative to get all of our product engineers thinking of docs as part of their launch for a new feature or a change to an existing one,” she says. “And so eventually all product engineers at Flatfile will contribute to docs in a more pronounced way, which includes contributing to the Mintlify repo.”

Getting Started with Mintlify

Want to set up docs like Flatfile? You can get started at or request a demo with our team.