Scaling beyond trading: building a real-time video auction feature and more for a European crypto exchange

Client background and market position

The client operates a consumer crypto exchange that generates transaction revenue when customers exchange one coin for another, and it serves European markets in four languages. After many years in the market, the business set a clear direction: broaden the platform beyond trading, give users more reasons to spend time on it, and increase the speed at which new ideas reach the market. The platform needed to be ready to carry all three.

What the platform needed before it could scale

• Technical debt accumulated across five years and several development partners. Consolidating it was the precondition for everything on the roadmap, because in a product that holds customer funds, reliability is the foundation of trust.

• The layer that stores and shares user information had grown organically. Every feature touching account data cost more to build than the last, which slowed delivery across the whole roadmap.

• A live auction format sets a high bar on three fronts at once. Bids have to be accurate to the moment, because a bid placed against a price that has already been beaten becomes a disputed transaction rather than a display issue. Each auction also runs several lots with their own end times, price limits and required bid increments, and all of it has to be handled automatically to avoid manual resolution. Finally, a product presentation and a bidding screen normally sit in two separate places, so interest created in one does not automatically become a bid in the other.

• MiCA and DORA set fixed deadlines. Both required product changes inside a live platform holding customer funds, and both represented an opportunity to strengthen user trust rather than just a compliance exercise.

• Three platforms, one product. The experience had to work on the web and as an iOS and Android app, with a single development effort behind all three rather than three products to maintain.

The work ran over two and a half years on a platform that stayed live and trading the entire time, so sequencing mattered as much as scope. Modernising the existing application came first, because everything on the roadmap depended on a foundation that could carry it without disrupting the users already on the platform. 

From there the work moved in four directions: protecting the trading core and its regulatory footing, making growth self-funding, opening a new revenue stream through live auctions, and placing that auction inside a live video presentation. Each addressed a specific point below.

• We consolidated the legacy frontend into one architecture. Application logic was restructured, and the frontend was brought into one architecture; then two complete redesigns and four languages shipped on that same foundation, with one build serving web, iOS, and Android. This is why new features and new markets reached users without a rebuild and without three separate products to maintain.

• We kept the coin trading module earning through MiCA and DORA implementation. The coin exchange module continued to be maintained and extended while newer features were built around it, and the MiCA and DORA changes were delivered on the regulator's timeline with the platform live. Transaction revenue was protected, and the right to operate across Europe was secured, with compliance visible to users as a signal of trust.

• We made growth self-funding with referral, gifting, and feature flags. Referral and gifting features let users send credit to other people, including those without an account, so an invitation arrives with value attached. Everything outside the core sits behind feature flags controlled from the back office, so campaigns launch or retire as a business decision rather than a development request.

• We built live auctions on a custom WebSocket layer. A custom WebSocket keeps the browser and server in step, and every event is handled explicitly: a lot closes the instant it expires, a finished auction stops accepting bids, and increments are validated on the server. The result is a revenue stream independent of trading volume, where every bid is placed against a current price, no outcome needs manual resolution, and the busiest interaction in the product carries no per-bid cost or external dependency.

• We placed the auction inside the live video stream. A presenter demonstrates the product while the bidding panel sits on top of the stream, in the format television shopping made familiar, with Stream Chat carrying the conversation alongside it. Interest and the bid now happen in the same place, and the audience stays present between lots.