Our product
Recoreo operates Gym Geek: The Smart Calorie Counter That Keeps You on Track. Launched in June 2025, our app has helped over 300,000 people lose, maintain or gain weight. We’re rated 4.8 stars on the App Store, and we’re quickly gaining market share with our unique take on weight management.
We also operate the gymgeek.com website, helping more than 1 million people a month calculate their calorie deficit and macros with our handy free tools.
Building our engineering team
Recoreo is a bootstrapped startup (with a proven and profitable product) and we’re now hiring our first engineers to take Gym Geek through the next stage of growth. This is an exciting opportunity to work closely with the product, users and contribute to the technical direction of the business.
As an engineer at Recoreo, you’ll work with a wide range of technologies, across our mobile app, web front-end and back-end APIs. We don’t expect prior experience in all areas, but you should be eager to learn beyond a single speciality.
Engineering principles and culture
- No silos - Engineers at Recoreo work across the entire stack, from mobile (~50%), frontend (~30%) and backend (~20%); using a diverse range of programming languages and technologies.
- We bias towards pairing - We tend to work together on complex or high-leverage problems more than typical engineering teams. We believe that pairing helps us move and learn faster, reduce mistakes and leverage our different perspectives and skillsets. For new engineers, it’s a great way to onboard and build confidence with our codebase.
- We prioritise mentorship and growth - We expect engineers to learn quickly, and we put in place the support, mentorship and growth opportunities to make it happen. Junior engineers are supported through regular pairing, code reviews and close collaboration with other engineers in the team.
- We experiment and learn - We don’t just build for the love of building. We’re grounded in experimentation and measurement. Every time we ship, we assess our success by measuring a metric or outcome. That could be something technical (like latency or reliability) or something product or commercial (like a conversion or retention rate).
Technology we use
Here’s a complete overview of the tech that we use at Recoreo:
Mobile app
- Expo/React Native/Typescript - Our mobile app is written in Typescript, leveraging the Expo framework. We use SQLite with the Drizzle ORM to persist user data. Very occasionally, we might need to write small amounts of Objective-C, Swift or Java.
Front-end
- React/Typescript - Our website is built with React (Razzle) and Typescript, and serves both long-form content as well as interactive content like our calorie calculators and macro calculators. Our website is a product in its own right, and we regularly A/B test new UI/UX to improve user engagement and conversion to our mobile app.
- Tailwind - We use Tailwind rather than pure CSS to style all of our webpages.
- Headless Wordpress/PHP - We use Wordpress as our content management system, although Wordpress does not directly serve to users. Instead, our React project uses Wordpress as a “headless” CMS, fetching content and metadata from the Wordpress API. We write only tiny amounts of PHP.
Back-end
- Node.js/GraphQL - A single GraphQL server is the back-end for both our mobile app and website, serving CMS content and metadata, food database search results and remote configuration for our app.
- AI - embeddings + chat completions - We use OpenAI models in a few places to improve the UX of our app. We use text vector embeddings to improve the quality of our food database search results, as well as the chat completions API (i.e. “chat model”) to interpret complex descriptions of meals or recipes.
- Search - SQLite/FTS5/Information Retrieval/Rankings - We built a bespoke search retrieval and ranking method to deliver the most relevant food database results in our app. We built this atop SQLite, which allows the database to be embedded offline (planned).
Infrastructure
- Docker/Kubernetes - All of our services are containerized and run on a Kubernetes cluster.
What we’re currently working on
Just a flavour of the kind of projects that engineers will work on at Recoreo:
- Apple Health integration - Our Apple/Google Health integration will allow users to track their activity level, as well as their calorie intake, in the Gym Geek app. Our Smart Calorie Adjustments feature, which adjusts a user’s calorie goal to keep them on track, will also need to be improved to factor in activity as well as calorie intake. This project is mostly front-end work, with a little math/stats to make the Smart Calorie Adjustments work correctly.
- User authentication - We will introduce authentication (sign in with Apple, Google, etc) to allow users to sign in across multiple devices, and back-up their data to the cloud. We’ll also allow users to opt-in to reminder emails, which will improve our short-term retention and user activation. This project is a mix of front-end and back-end work.
- Food database imports/search - We will keep our food database fully up to date by automating imports and quality checks. Currently, this is a manual and periodic process. This project is fully back-end work.
- AI insights - We plan to introduce more AI features into our app, to give users better insight into their progress. To start, we will build an AI overview feature in our Insights tab to give users day-to-day feedback. This is a mix of front-end, back-end and AI prompting work.
- Monitoring and alerting - This project will add better monitoring and alerting to our Kubernetes set-up, so we have better visibility into performance and reliability.