Building FlipLytics: My Journey Creating a SaaS Platform for eBay Sellers

What is FlipLytics?

FlipLytics is a SaaS platform built specifically for eBay sellers to help manage their business more efficiently. Prior to FlipLytics, most sellers had to rely on manually updating spreadsheets to track their profits—a tedious and error-prone process. Even then, they were limited to raw figures with no effective way to analyze the data.

FlipLytics automates this process by fetching listing and sales data directly from eBay. The only manual input required from users is how much they paid for an item and the associated shipping costs. The software handles the rest—providing graphs, profit tracking, ROI analysis, and other key business metrics. Users can filter their data by brand, tag, source location, and more.

Origin Story

The idea for FlipLytics came from personal experience. My business partner and I were both selling on eBay and struggling to monitor our sales efficiently. We needed a better solution, so we decided to build it ourselves.

Tech Stack

We chose a stack that would allow us to move quickly while still being robust and scalable.

On the backend, we leaned into the power and flexibility of Python with Django as the core framework. GraphQL was our choice for the API layer, providing fine-grained data fetching capabilities that fit perfectly with the needs of our frontend. For background processing, Celery handled asynchronous tasks smoothly, while Redis served as a fast and reliable queue broker. PostgreSQL was a no-brainer for the database, offering the relational integrity and performance we needed.

On the frontend, we built a modern, reactive interface using React with TypeScript and Vite for a fast and efficient development experience. Apollo GraphQL enabled seamless communication with the backend, and TailwindCSS made styling both rapid and consistent across the app.

For the marketing website, we went with Next.js combined with TailwindCSS to keep the branding aligned and benefit from Next.js’s static generation and SEO capabilities.

Deployment was handled with Docker, making the environment consistent across development and production. We host everything on DigitalOcean, using GitHub Actions to automate our CI/CD pipeline.

Development Challenges

The most challenging aspect of building FlipLytics was authentication. Managing authentication between the frontend, backend, and eBay was a major hurdle. After weeks of troubleshooting and running into countless bugs, I hit a point where nothing seemed to work.

Taking a break turned out to be the best decision. With a fresh mindset, the solution became clear: instead of trying to create one complex AuthGuard to handle everything, I broke it down into smaller guards, each responsible for a specific task:

  • Checking if the user is authenticated
  • Verifying email address
  • Confirming eBay account linkage
  • Ensuring data is synced

This modular approach not only solved the problem but became one of the most reusable components I’ve built—I've used it in several projects since.

Lessons Learned

The biggest lesson I learned was the importance of resilience. Things won’t always go to plan. Bugs and issues are part of daily life when coding, especially when building a SaaS platform from scratch. When you're stuck, taking a break and returning with fresh eyes can make all the difference.

If I were to start over, sure, I could write more efficient code now—but only because of the hard-earned lessons learned through trial and error. We’re currently refactoring and improving parts of the platform that were built early on, and the difference in quality is remarkable.

What’s Next?

FlipLytics is live. We’re actively working on improving the user experience—especially around data tables, filtering, and batch actions. Our roadmap includes:

  • Expanding support to marketplaces outside the UK (USA, Canada, Australia)
  • Enhanced analytics and visualizations
  • Business reports and goal tracking

There’s still a lot to build, but we’re excited for what’s ahead.

Thanks for reading about my journey building FlipLytics. If you're an eBay seller, give it a try—and feel free to reach out if you have feedback or ideas.