As a Senior iOS SDK Engineer, you'll design, implement, and optimize core SDK features, maintain integrations with ad networks, and improve SDK usability by collaborating with publishers and product teams.
Senior iOS SDK Engineer
About CloudX
About The Team
What you'll do
Who you are
Pay and Benefits
About CloudX
At CloudX we’re building a new supply-side advertising platform for mobile publishers. We’re convinced that an AI-native product will significantly advance the state of the art in mobile advertising; we recently raised a $30M Series A in order to bring this dream to life. We have a long history of innovation in this space — our founding team previously built MoPub (sold to Twitter for $350M) and MAX (acquired by AppLovin). Our new platform combines real technical improvements like verifiably fair auctions with a truly AI-native product experience to give publishers unprecedented control over their ad monetization strategy.
Our Engineering team is distributed and remote — spanning UTC-8 to UTC+6, with core working hours of roughly the US Eastern business day. We have a strong ownership culture and are heavily collaborative, relying primarily on asynchronous, written, communication for coordination. We ship daily and believe that fast CI and good test coverage is the best way to remain productive as we scale. We’re small and high trust; we optimize for rapid iteration and experimentation. Everyone has access to the latest AI tools, but rather than generating vibe-slop we use them pragmatically to build better products. We are lucky to work closely with our talented Product and Business teams to make sure we’re building the right things. It’s a true early-stage startup with lots of important work to go around.
The Mobile team builds the core infrastructure that will power revenue for thousands of mobile apps. At scale, our SDK will run in production apps with hundreds of millions of daily active users, processing billions of ad requests per month. We're a small, high output team committing code daily.
You'll own the critical path. The SDK is the first point of contact between publishers and CloudX's marketplace, so reliability and performance aren't optional. Every line of code you write affects real revenue for real businesses. We move fast, ship often, and measure everything.
As a Senior iOS SDK Engineer, your key responsibilities will be to:
- Collaborate with the product team to design and implement core SDK features
- Build and maintain integrations with third-party ad networks (Meta, Google AdMob, etc.)
- Optimize SDK to be seamless in host apps: minimize startup impact, reduce binary size, manage resources efficiently, and handle errors gracefully without affecting app stability
- Engage directly with publishers to diagnose real-world issues and improve SDK usability, reliability, and integration experience
We encourage you to apply if you meet these requirements:
- Proven experience building and maintaining production iOS apps or SDKs
- Strong proficiency in Objective-C (Swift experience a plus)
- Expert-level understanding of iOS concurrency (GCD, async/await, threading, memory management)
- Deep understanding of iOS internals: runloops, networking, background execution, app lifecycle
- Strong testing and debugging discipline
- A genuine builder: Someone who codes daily, sweats the details, and has shipped complex systems, not just talked about them. You get energy from solving hard engineering problems yourself.
- A clear, concise, communicator: You can take a messy problem and make it legible, explaining trade-offs to engineers, PMs, and execs without hand-waving.
- A startup operator with good instincts: You know when to ship fast, when to slow down, and how to navigate ambiguity without waiting for perfect specs or marching orders.
- An owner, not a passenger: You turn loosely defined problems into real solutions, care deeply about whether the product actually works, and use AI as a force multiplier, not a crutch.
While not required, we’re particularly interested in candidates with:
- Experience building developer-facing SDKs or libraries, including documentation, versioning, and integration support
- Experience distributing SDKs via CocoaPods / Swift Package Manager / binary frameworks
- Cross-platform SDK experience with Flutter, React Native, or Unity development
- Mobile advertising experience: Understanding of ad mediation, waterfalls, etc.
In general, we’re looking for people with grit, passion, and talent. If you’re not sure if this role is an exact fit, we encourage you to apply. Many members of our team have had interesting career paths and we relish the chance to work with extraordinary individuals.
The annual US base salary range for this role, and other engineering roles, is $150,000 – $300,000. This salary range is broad in order to accommodate a wide range of candidates; the interview process will narrow it down based on a number of factors, including your experience, qualifications, and location.
We offer equity compensation and top-tier medical, dental, and vision benefits.
We also have a generous hardware budget for a computer, monitor, and other core equipment necessary to work effectively on a remote team.
We care about the quality of your work more than the specific hours you spend getting it done, and try to minimize the number of synchronous meetings in favor of greater flexibility. There is no in-office requirement.
CloudX San Francisco, California, USA Office
San Francisco, CA, United States
Similar Jobs
Fintech • Mobile • Payments • Software
The Senior iOS SDK Engineer will design, build, and support SDKs for in-app subscriptions, focusing primarily on iOS while also engaging with Android and hybrid SDKs. Responsibilities include shipping high-quality products and collaborating effectively in a remote team.
Top Skills:
iOSJetpack ComposeKotlinPythonSwiftSwift Ui
Cloud • Fintech • Food • Information Technology • Software • Hospitality
As a Staff Software Engineer, you'll lead a team in developing and delivering scalable software solutions for employee management in the restaurant industry, focusing on enhancing customer and employee experiences.
Top Skills:
GraphQLJavaKotlinReactRestTypescript
Artificial Intelligence • Big Data • Cloud • Information Technology • Software • Cybersecurity • Data Privacy
As a Strategic Sales Engineer, you'll provide technical direction, support sales efforts, and develop integrated solutions addressing customer needs to exceed sales quotas.
Top Skills:
Backup And Disaster RecoveryCloud Data ManagementData AnalyticsSan (Storage Area Network) Systems
What you need to know about the San Francisco Tech Scene
San Francisco and the surrounding Bay Area attracts more startup funding than any other region in the world. Home to Stanford University and UC Berkeley, leading VC firms and several of the world’s most valuable companies, the Bay Area is the place to go for anyone looking to make it big in the tech industry. That said, San Francisco has a lot to offer beyond technology thanks to a thriving art and music scene, excellent food and a short drive to several of the country’s most beautiful recreational areas.
Key Facts About San Francisco Tech
- Number of Tech Workers: 365,500; 13.9% of overall workforce (2024 CompTIA survey)
- Major Tech Employers: Google, Apple, Salesforce, Meta
- Key Industries: Artificial intelligence, cloud computing, fintech, consumer technology, software
- Funding Landscape: $50.5 billion in venture capital funding in 2024 (Pitchbook)
- Notable Investors: Sequoia Capital, Andreessen Horowitz, Bessemer Venture Partners, Greylock Partners, Khosla Ventures, Kleiner Perkins
- Research Centers and Universities: Stanford University; University of California, Berkeley; University of San Francisco; Santa Clara University; Ames Research Center; Center for AI Safety; California Institute for Regenerative Medicine
