Mobile SDK Developer - Hybrid - Stockholm

About Sinch

Sinch is pioneering the way the world communicates. More than 150,000 businesses — including Google, Uber, Paypal, Visa, Tinder, and many others — rely on Sinch’s Customer Communications Cloud to power engaging customer experiences through mobile messaging, voice, and email. 

Whether you need to verify users or craft omnichannel campaigns, Sinch makes it easy. Our AI-infused Super Network, APIs, and applications ensure you can connect with your customers reliably and securely, at every step of their journey. 

At Sinch we “Dream Big”, “Win Together”, “Keep it simple”, and “Make it Happen”. These values are our foundation! 

Description

We are a forward-thinking team creating cutting-edge, cloud-based communication solutions. Our mobile client SDKs are key to how our customers integrate their products with our platform. We have clients ranging from small businesses to large enterprises, and their mobile apps are used by millions of people worldwide. By developing our voice and video SDKs together with the team, you will play a pivotal role in powering all those real-time conversations. 

As a Mobile SDK Engineer, you’ll take ownership of developing and maintaining high-performing mobile SDKs while contributing to all stages of the software lifecycle. In this role, you will: 

• Develop SDKs using WebRTC technology to optimize real-time communication features. 

• Work with the team to align SDK APIs and features across multiple platforms, including iOS, Android, and Web/JavaScript. 

• Develop cross-platform solutions using a C++ codebase shared between iOS and Android.  

• Design APIs with simplicity in mind while maintaining modularity, extensibility, and API stability over time. 

• Write clean, testable, and maintainable code, with a focus on system performance and scalability. 

• Enhance automation, streamline CI/CD pipelines, and troubleshoot issues proactively. 

• Influence architectural decisions and actively contribute to enhancing our development and operational practices. 

Requirements 

• Professional expertise in modern C++, especially in mobile applications development. 

• Professional experience developing for the iOS and/or Android platform. 

• Experience with at least one of Kotlin or Objective-C/Swift. 

• Experience working in Linux/macOS development environments and CI pipelines. 

• Strong communication skills and a collaborative mindset. 

• A passion for clean, testable code and modern software practices. 

Good to have 

• Experience with WebRTC protocols and NAT traversal, including ICE, STUN, and TURN, is a significant advantage. 

• Experience developing software libraries and/or SDKs consumed by other developers. 

• In-depth knowledge of network protocols such as IP, TCP, UDP, and DNS. 

• Great debugging and troubleshooting skills. 

Embrace the challenge and join us! You will have the chance to:

• Work with a talented and diverse team in a culture that values innovation and collaboration.
• Take on meaningful challenges and grow with the latest technologies.   
• Enjoy flexibility with hybrid work options and a healthy work-life balance.   
• Benefit from competitive salaries and a comprehensive benefits package, including healthcare insurance, pension contributions, and wellness allowance. 

Our Hiring Process

We are committed to ensuring a recruitment process that is fair, objective, consistent, and inclusive. Our approach includes structured, competency-based interviews designed to evaluate your skills, experience, and qualifications relevant to the role. At times, we may include a data-driven assessment to enhance our hiring success and identify candidates likely to excel.  

We believe in a two-way process and encourage you to ask questions throughout the journey.  If this role isn't what you're looking for, please explore the other opportunities listed on our career page: . No matter who you are, we hope you find an exciting path forward - hopefully with us!