Senior iOS Engineer – Learning Experience
in This Role Babbel is looking for a Senior iOS Engineer to help change the future of language learning within our Learning Experience teams. This is an Individual Contributor role with team-level scope. You will work closely with product and engineering managers, designers, subject matter experts, and cross-platform engineers to build Babbel's core learning experiences --- from the learning path and exercise player to real-time speaking and conversation practice. You own the experience end to end: it ships as a distributable Swift package consumed by Babbel's main iOS app, and you follow it there --- integration points, A/B experiments, rollout. And you'll do this the Labs way: AI coding agents are a first-class part of how we design, build, test, and review. How You'll Make an Impact - Take part in all product development phases: discovery, prototyping, proposing solutions, implementing, reviewing, testing, and deploying learning experiences.
- Own the engineering side of our feature workflow: shape the PRD together with product, then pick it up --- 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 --- the learnings feed the product, even when the code doesn't.
- Design and evolve the public API of our Swift package with deliberate versioning and breaking-change discipline --- and land it in the main app: integration points, A/B experiments, rollout.
- Collaborate closely with product managers, designers, and other cross-functional teams to define and implement features that enhance how learners progress through their learning path, exercises, and speaking practice.
- Maintain and proactively improve the technology stack, build system, and the AI-agent conventions (skills, project rules, documentation) the whole team relies on.
- Share what you learn: technical documentation for core features, and knowledge actively passed on to colleagues. Your Skills and Qualifications - 5+ years of experience building scalable iOS applications using Swift.
- An AI-first mindset --- a strong must for us. You have actively embraced AI coding tools in your own work --- not just autocomplete, but directing agents through real feature work and critically reviewing what they produce --- and you treat prompts, skills, and project conventions as engineering artifacts maintained like code. Deep experience with our specific agent stack isn't required --- demonstrated adoption and genuine enthusiasm are.
- Strong, up to date Swift --- including Swift 6 strict concurrency (actors, Sendable, isolation) and structured concurrency.
- Deep SwiftUI experience and a solid grounding in the Apple ecosystem and Human Interface Guidelines; you think in state-driven UI and know where the framework's sharp edges are.
- Strong opinions on state management and testable architecture --- experience unidirectional-data-flow architecture, and willingness to go deep on ours.
- Testing as a first-class habit: deterministic, exhaustive unit tests with controlled dependencies, snapshot tests where the UI is the contract --- not coverage theater --- and the CI/CD discipline to keep them green.
- Experience designing module boundaries, frameworks, or SDKs that other teams consume --- ideally as distributable Swift packages --- and the API-stability discipline that comes with it.
- Experience designing or consuming evolving JSON APIs and collaborating with contract-first backend teams.
- An eye for good architectural decisions based on feature requirements, and knowledge of how to balance technical debt against delivery speed.
- Comfort with ambiguity and fast iteration: directions evolve as we learn, and prototypes are a tool, not a deliverable.
- Clear, concise communication, an open mindset for feedback, and enjoyment in working closely with design and product in a lean environment.
- Fluency in written and spoken English. Nice to Have - Hands-on experience with The Composable Architecture and the Point-Free ecosystem (swift-dependencies, swift-sharing).
- Hands-on experience with agentic coding setups (e.g. Claude Code): agent skills, MCP servers, CLAUDE.md-style project conventions.
- Experience with Tuist or other project-as-code tooling at scale (modular workspaces, binary caching).
- Experience with Swift Testing (the modern successor to XCTest).
- Experience with real-time client features --- live audio capture, streaming over WebSocket/WebRTC, low-latency interactions.
- Comfort navigating a legacy RxSwift/MVVM-C codebase --- you'll help integrate our package into Babbel's main iOS app while it migrates to the new stack.