Senior iOS Engineer

Stack

Responsibilities

• ▹Take part in all product development phases: discovery, prototyping, proposing solutions, implementing, reviewing, testing, and deploying learning experiences
• ▹Own the engineering side of the feature workflow: write the technical spec, agree interface contracts with backend and partner teams, slice the backlog, and build
• ▹Build quick prototypes to de-risk product ideas
• ▹Design and evolve the public API of the Swift package with deliberate versioning and breaking-change discipline, and land it in the main app
• ▹Collaborate closely with product managers, designers, and cross-functional teams to define and implement learning path, exercise, and speaking-practice features
• ▹Maintain and improve the technology stack, build system, and the AI-agent conventions the team relies on
• ▹Share technical documentation for core features and pass on knowledge to colleagues

Requirements

• ▹5+ years of experience building scalable iOS applications using Swift
• ▹An AI-first mindset, with active use of AI coding tools to direct agents through real feature work and critically review their output
• ▹Strong, up-to-date Swift knowledge, including Swift 6 strict concurrency (actors, Sendable, isolation) and structured concurrency
• ▹Deep SwiftUI experience and solid grounding in the Apple ecosystem and Human Interface Guidelines
• ▹Strong opinions on state management and testable architecture, including experience with unidirectional-data-flow architecture
• ▹Testing as a first-class habit: deterministic unit tests with controlled dependencies and snapshot tests
• ▹Experience designing module boundaries

Nice to have

• ▹Experience with Babbel's specific AI-agent stack (not required, but a plus)

Soft skills

About the company

Babbel Labs is an AI-first, independent company within the Babbel group, based in Berlin, building the future of language learning by bringing together AI, R&D, and product.