iOS Developer - Native Mobile Platforms (Kotlin Multiplatform)

At iO Amsterdam, we build modern, scalable native mobile platforms for demanding clients in sectors including finance, healthcare and utilities. We combine true native quality with the efficiency of shared business logic via Kotlin Multiplatform (KMP). Think multi-label apps for multiple brands and countries, with security, compliance and performance as non-negotiable requirements.

To further develop this approach, we're looking for an experienced iOS developer who thrives on architecture, quality and modern mobile stacks – and who can strengthen our team with real technical depth.

How we work

• Architecture-first: we build on a proven KMP foundation, with a large part of the fundamental mobile architecture already in place (auth, networking, storage, logging, testing);
• Shared where it pays, native where it matters: business logic in Kotlin, platform-specific UX in SwiftUI/Compose;
• Multi-label by design: new brands and variants are added through configuration, design systems and tooling – not copy-paste code;
• Security by design: security & compliance are built into our components and pipelines from the start, not bolted on afterwards;
• AI & automation: we invest in AI-assisted testing and smart tooling to deliver faster, more securely and more consistently;
• As an iOS developer, you'll be one of the key figures putting this approach into practice and helping to refine it further.

What you’ll be doing

As an iOS Developer at iO, you will:

• Build high-quality native iOS apps (Swift/SwiftUI) as part of our mobile platforms;
• Work closely with Android, KMP and backend colleagues to combine a shared core (business logic in Kotlin) with a best-in-class iOS experience;
• Help deliver multi-label solutions: one platform, multiple brands and countries, each with their own look & feel and functionality;
• Contribute to architectural decisions (KMP, modularisation, security, API design) and introduce iOS best practices;
• Help build reusable components and frameworks (e.g. banking and security platforms) so future projects can launch faster and more securely;
• Work on apps where security, privacy and compliance are not afterthoughts, but fundamental requirements (e.g. banking & healthcare apps).

Why you're the perfect iOS Developer

You have

• 5+ years of experience as an iOS developer with Swift & SwiftUI;
• In-depth knowledge of the iOS ecosystem;
• Architecture knowledge such as MVVM, Clean Architecture or equivalent;
• Experience in testing (unit/UI tests), debugging and performance analysis;
• Experience with CI/CD for mobile (e.g. Azure DevOps, GitHub Actions);
• A serious focus on security & privacy: Keychain, secure storage, networking, handling sensitive data;
• Experience in enterprise environments: complex backends, APIs, identity (OAuth/OIDC) and associated stakeholders;
• Strong communication skills; you can explain your decisions to both developers and non-technical stakeholders;
• A proactive, product-oriented mindset: you think in terms of value for the user and the client, not just tickets.

Nice-to-haves

• Experience with or a strong interest in Kotlin Multiplatform (KMP) or other shared-code solutions;
• Experience of knowledge of The Composable Architecture (TCA);
• Experience with Android (Kotlin, Jetpack Compose) or a willingness to understand the KMP side;
• Experience with white-label / multi-brand apps (multiple brands from a single codebase);
• Knowledge of security frameworks (device binding, RASP) or highly regulated domains (banking, insurance, healthcare);
• Experience with automated testing, such as screenshot testing or AI-driven UI tests;
• Experience with AI tooling, such as Claude Code, Cursor or GitHub Copilot.

What we offer

25 vakantiedagen

Op basis van een 40-urige werkweek.

Reiskosten & vakantiegeld

Uiteraard kun je rekenen op 8% vakantiegeld. Daarnaast hebben we verschillende mobiliteitsregelingen, maar afhankelijk van jouw functie en voorkeur een keuze.

Goede pensioenregeling

Jij legt 4% in en iO vult de rest aan tot de volledige premie.

Hybride werken

Een goede werk- en privébalans is superbelangrijk. Samen met jouw team maak je afspraken over wanneer én waar je werkt.

Gezonde snacks & lunch

Op iedere iO campus pak je de hele dag een gezond tussendoortje en kun je tegen een kleine vergoeding gezond én gevarieerd lunchen.

Persoonlijk ontwikkelbudget

Zet jaarlijks € 3.000,- in om jezelf te ontwikkelen, in je vak of als persoon, met trainingen, events of cursussen.

Milestones & celebrations

En bovenal zijn we bij iO ook gewoon een gezellige club mensen, al zeggen we het zelf. Het Fun & Party-team op jouw campus staat op z'n tijd dan ook garant voor de leukste feestjes.