The Secret Ingredient: How Rails Helps Cookpad Serve 100M+ Home Cooks.

Cookpad is the world’s largest recipe-sharing platform, where over 100 million home cooks search, upload, and share their own recipes each month. Founded in Japan, it’s become a staple in millions of kitchens and has since expanded to more than 70 countries and 35 languages.

Originally built on ColdFusion in 1997, Cookpad migrated to Ruby on Rails in 2007 to improve development speed, flexibility, and long-term maintainability. Today, Rails is still the backbone of Cookpad’s infrastructure, powering everything from recipe search to mobile APIs.

Why Rails?

At Cookpad, new features are developed as experiments and validated through user feedback. But by the mid-2000s, their ColdFusion-based system was slowing them down. The codebase had become complex and difficult to maintain, making it hard to introduce new features or iterate quickly. They needed a framework that supported rapid experimentation without too much overhead, so they started looking for an alternative.

In 2007, they decided to migrate to Rails. Even though no one on their team had prior experience with it, Rails’ convention-over-configuration approach fit perfectly with their need for fast prototyping. Instead of spending time on setup and low-level implementation details, the team could focus on building, testing, and improving features based on user feedback.

That shift paid off quickly. Development sped up, releases became more frequent, and Cookpad was able to expand beyond Japan into 70 countries and 35 languages. Just two years later, in 2009, the company went public on the Tokyo Stock Exchange, all with Rails quietly running under the hood.

How Rails Powers Cookpad Today

Today, Cookpad mostly runs as a Rails monolith, with a few services extracted where it made sense (like search and payments). The same backend also serves as the API for both iOS and Android apps, which keeps development simpler, reduces redundancy, and keeps the user experience consistent across platforms.

Because Cookpad’s workload is mostly read-heavy from users browsing recipes, database performance and scalability are critical, so Rails’ seamless integration with MySQL on AWS RDS was a big factor in the team’s decision to choose the framework. To keep response times fast, they use Memcached and Redis to cache common queries and reduce database load. ActiveRecord’s query optimizations combined with careful indexing and eager loading help keep things responsive as traffic and the recipe catalog grows.

Because Cookpad’s workload is mostly read-heavy from users browsing recipes, database performance and scalability are critical.

For background jobs, Cookpad uses an event-driven setup built around Kafka (MSK). Tools like Karafka and Resque handle asynchronous tasks, so that resource-heavy operations don’t block user requests, keeping the platform fast and reliable as it scales.

Other key Rails features that help Cookpad scale:

• ActiveRecord ORM – Provides a structured way to work with databases, enabling engineers to handle a massive recipe catalog while maintaining performance.
• Internationalization (I18n) support – Baked-in localization features made it easier to expand into 70+ countries and 35+ languages.
• Template rendering system – Keeps logic separate from presentation, making front-end updates cleaner and reducing development friction.
• Test-driven culture – Encourages a quality-first approach, allowing Cookpad to deploy straight from the main branch multiple times per day with confidence.

On the web, Cookpad leans on Hotwire, using Turbo and Stimulus controllers creating responsive, dynamic interfaces without relying on heavy JavaScript frameworks. This Rails-native approach makes the UI fast and flexible while letting the backend remain in control.

Rails’ conventions and cohesive tooling also make onboarding new engineers faster. Developers join the team and are immediately able to contribute meaningful work, often within days. Combined with tools like feature flags and a strong testing culture, Cookpad can experiment, evolve, and scale without fear of breaking things.

Investing Back Into Rails

Cookpad hasn’t just used Rails, they’ve helped shape it. Over the years, they’ve employed members of the Rails Core team and supported Ruby directly by employing core maintainers Koichi Sasada and Yusuke Endoh for many years to work on the language, helping define and refine core features and performance across both ecosystems.

They’ve also released several open-source tools, including:

• chanko – A feature flagging framework for gradually rolling out new features.
• barbeque – A background job system built to manage large-scale workloads efficiently.

Beyond code, Cookpad engineers have often spoken at Rails conferences, contributed directly to Rails and Ruby, and improved widely used libraries. Today, Cookpad continues to invest in and support the long-term growth of the framework and its ecosystem as a founding member of the Rails Foundation.

Nearly two decades after their migration, Cookpad’s choice of Rails continues to pay off, providing the foundation for a fast, global, and resilient platform that keeps millions of home cooks connected every day.