Whitebox

The context

Whitebox is a BaFin-regulated digital wealth manager (robo-advisor) based in Freiburg, Germany, with native iOS and Android apps. I joined as a Senior iOS Engineer and was operating at principal scope within three months. The Engineering Manager then appointed me Principal iOS Engineer and technical leader, acting as his direct counterpart on architecture, planning and delivery decisions.

Architecture

The iOS codebase had grown organically. I moved it to a strictly enforced architectural format with explicit module boundaries and dependency rules, so it became predictable to extend, safe to refactor and testable end to end.

I also modernized it around current Swift practice, with Swift Concurrency and large-scale Combine pipelines, and led the migration path toward the Observation framework.

Security for a regulated product

I defined and implemented the SSL certificate pinning strategy across ACM deployments, so trust validation held consistently in every environment.

Testing

I established a testing strategy built on Swift Testing, bringing business-critical systems such as maintenance mode and support availability under automated coverage.

Release engineering

The app spans six deployment environments: Dev, Dev-Wealth, Staging, Staging-Wealth, Sandbox and Production. I automated every build the team distributes for QA and production with Fastlane and GitHub Actions.

To close the last manual step, I built an App Store Connect webhook proxy that triggers release lanes automatically once a build is distribution-ready. Alongside it came automated release tagging and a QA-approval status check that blocks unverified merges.

Localization

I introduced POEditor as the localization system, replacing ad-hoc string handoffs with a pipeline that pulls translations into the app on CI. It was adopted beyond the iOS team as the company standard.

AI engineering

I drove the team’s AI engineering initiative, introducing Claude Code with codebase-specific skills, rules and MCP integrations (GitHub, Jira, Figma, Slack). AI-generated code follows the app’s module boundaries and conventions instead of needing to be rewritten.

Leadership

I interviewed engineering candidates alongside the Engineering Manager, focused on technical reasoning and culture fit. I mentored engineers through regular one-on-ones and hands-on review, building a culture where the quality bar is held by the whole team rather than enforced by one person.