I'm Antonio, iOS Engineer at UserTesting, on the Participant Experience team: the apps people actually open to run a test. I own the full lifecycle, from build to distribution, and sit close enough to product and design to shape what ships as well as how it ships.
Three and a half years at XING before that, owning the job-application flow end to end. I framed the hypotheses, ran the A/B tests myself, and moved apply rate ~120% above where I started, without letting test coverage drop below 95%.
Started shipping iOS in 2020 at NexPlayer: code I wrote ended up inside Sky, HBO and Vodafone's video SDKs. A consulting stint at Hiberus (XING, 20 Minutos, Banca March) came right before XING took me on directly.
Lately, agentic workflows with Claude Code and Codex have changed how fast I ship, on iOS and now React Native too. The lab is where that speed turns into something useful for someone else, and it's the direction I want to keep growing in: less time explaining what's technically possible, more time deciding what's worth building.
I'm Antonio, iOS Engineer at UserTesting, on the Participant Experience team: the apps people actually open to run a test. I own the full lifecycle, from build to distribution, and sit close enough to product and design to shape what ships as well as how it ships.
Three and a half years at XING before that, owning the job-application flow end to end. I framed the hypotheses, ran the A/B tests myself, and moved apply rate ~120% above where I started, without letting test coverage drop below 95%.
Started shipping iOS in 2020 at NexPlayer: code I wrote ended up inside Sky, HBO and Vodafone's video SDKs. A consulting stint at Hiberus (XING, 20 Minutos, Banca March) came right before XING took me on directly.
Lately, agentic workflows with Claude Code and Codex have changed how fast I ship, on iOS and now React Native too. The lab is where that speed turns into something useful for someone else, and it's the direction I want to keep growing in: less time explaining what's technically possible, more time deciding what's worth building.
Own the full lifecycle of the B2C iOS and React Native apps people use to take a test on their device: build, internal and App Store distribution, monitoring. Build the team’s own AI agents on top of Datadog via MCP. Embedded in product, weighing in on decisions before they reach the backlog.
Owned the job-application flow end to end: the path from match to applied, on both the candidate and recruiter sides. Lifted apply rates ~120% over where I started, pushed test coverage from 60% to 95%+, and cut build times ~40% on a fully modular SPM codebase. A/B-tested most of it.
Built the iOS architecture for the 20 Minutos news app from scratch. Shorter rotations across XING and Banca March in between. Got used to dropping into a new codebase and being useful by week two.
First iOS job. Worked on a video streaming SDK used by major broadcasters across iOS and Android. Implemented multi-camera synchronized playback and interactive video, in Swift, Kotlin, AVFoundation and ExoPlayer.
Software a medida for SMEs in Spain. Internal tools, AI integrations, custom dashboards. Real client work.
Random coordinates, real weather. A Swift 6 concurrency sandbox.
MapKit and SwiftData, properly. Bus trips, routes, issues at specific stops.
Finance for the spreadsheet-fatigued. Building slowly, App Store soon.
