Matjaž Čuk

A regulated payments app with its own digital identity platform, built by USBC (formerly GlobalID). I worked remotely as a back-end developer and was the API platform lead across four engineering teams.

I built the identity verification users go through during onboarding. It connects to outside providers for document and liveness checks, bank identity and phone verification, and each level a user reaches unlocks higher transaction limits. I also built a simulated verification flow, so testing no longer depended on the outside provider.

I set the company's API standard and built the automated check that enforces it on every code change, with help from an AI reviewer. The APIs of nine services are combined into two products, one for partners and one for the company's own apps.

I made the gateway check identity on every request by default and moved the platform onto a new sign-in provider. I let partner companies manage identities for their own users, rebuilt webhook notifications so they are delivered in order, and set rate limits per client instead of per IP address.

Before the move to payments, I built much of the company's digital credentials platform.

A cloud platform that configures and manages the access points behind Plume's self-optimising Wi-Fi, across 60 million locations. I was a back-end developer on the controller and the services around it for over two years.

I was the main developer on the power saving mode, which cut access-point power draw to about a third of normal by powering down radios when usage allowed. It switched on when real-time device activity showed a network was idle, or on a schedule. I designed the limits that kept it from affecting users: it only ran at night, and not on networks with too many devices or
access points.

I also switched the optimisation service from stored snapshots to live data from the controller, so decisions used the current state of each network, and enriched mobile network scans from the access points with country and operator.

On the controller I built remote deletion of a device's saved configuration and automatic cleanup of disconnected devices. I also worked on radio transmission power, support for the UNII-4 band, feature support per device model and app prioritisation rules.

A real-money sports betting exchange where users bet against each other, and the platform matches the bets, tracks liability and settles them. I was a back-end developer on it for three years, and its tech lead from 2021.

I raised the exchange's throughput tenfold, from 20 to 200 bets per second. The hard part was keeping bets correctly matched between users while many were placed at the same time, and I also fixed race conditions in how a matching bet was picked.

I moved the exchange's running totals onto real-time stream processing, and built jobs that track matched amounts and risk per sport and tournament. I wrote the tools we used to load-test bet submission, and added shared monitoring so operations across the exchange reported their success and timing.

As tech lead I owned architecture decisions, mentored the team and led the upgrade to a current Java version. I also built suggestions for linking events and markets from another exchange to our own.

A platform that lets bookmakers hand over the management of their betting risk to Sportradar. Every bet is checked against the bookmaker's limits and trading rules before it is accepted. I joined in 2014 as one of its first three developers in Ljubljana, stayed a core developer until 2019, and was team lead from 2018 as the team grew from 3 to over 30 people.

Over that time MTS grew from 1 million bets a month to 20 million a day and became one of the company's top-grossing products. I worked on how bets came in, were checked and stored, and on the rules bookmakers configure, from limits to reduced stake offers, cancellation and cashout.

I moved the configuration store behind the trading rules to a new database, with servers picking up changes as they happen. I built the migration of bets to a new store, with a cross-check that none were missing, and changed bet exports to stream instead of loading everything into memory. I also added per-client access control, an audit log of configuration changes, and an
end-to-end test framework covering the main betting scenarios.