Junior iOS Developer

Smadex is a cutting-edge ad-tech company: we process more than 4 million ad requests per second, replying in under 100ms. Every day, we generate several TBs of data that need to be processed, analyzed, and aggregated so that our real-time components get smarter everyday. If you’re passionate about building high-performance mobile solutions and thrive in a fast-paced, challenging environment, we want to hear from you!

This is a full-time hybrid position based in Barcelona.

We are looking for a Junior iOS Developer to work under the guidance of our Senior iOS Developer, and contribute to transforming our new advertising SDK from a prototype into a robust, high-performance product. This role is perfect for someone early in their career who wants to gain real-world experience, mentorship, and grow into a strong iOS engineer.

The Opportunity

• Learn and apply best practices in writing clean, maintainable, and well-tested Swift code.
• Work together with the Senior iOS Developer to implement new features and core functionalities.
• Gain hands-on experience identifying, debugging, and resolving issues in a real-world product.
• Participate in code reviews and learn from constructive feedback.
• Work closely with both iOS SDK and backend teams, building a solid foundation in cross-team collaboration.

Requirements and Qualifications

• Hands-on experience with iOS development (personal projects, coursework, or internships).
• Basic knowledge of Swift programming.
• Curiosity about how mobile apps communicate with RESTful APIs.
• A strong desire to learn, proactive attitude, and problem-solving mindset.
• Good communication skills and team spirit.
• Genuine passion for mobile technology and eagerness to grow as an iOS developer.

Bonus Points

• Experience building or maintaining an iOS library/SDK.
• Experience with UIKit.
• Familiarity with multithreading concepts on iOS.
• Experience with performance profiling and debugging using Xcode Instruments.
• Experience with unit testing (XCTest) or UI testing frameworks.
• Personal projects on GitHub or the App Store that you can share with us.
• Familiarity with Android development is a plus.

Please note we do NOT provide VISA sponsorship. Candidates without a legal permit to work in Spain will not be considered.

What’s in it for you

• Integrate a highly motivated and young team.
• Great compensation package.
• Top location in the heart of Barcelona with a rooftop terrace, barbecue, and a fully stocked fridge.
• Great work-life balance: work from home (2 days per week), flexible hours.
• LinkedIn Learning and training opportunities.
• Meal vouchers - Ticket Restaurant monthly allowance.
• Monthly gym allowance to use in up to 30 DIR gyms around the city.
• Monthly TGIF events and regular team-building activities.
• Fun and friendly work environment with talented marketers and engineers from over 40 countries.

If you want to know more about us visit our website Smadex.com, and for a sneak peek of the cool stuff we build, check this video out!