Senior Staff Prototyping Engineer, iOS

Description About Slack Slack is your Digital HQ — bringing people, apps, customers, and AI agents together in one place. Millions of people use Slack every day to communicate, collaborate, and get work done. As work becomes increasingly distributed and AI-powered, Slack is redefining how teams operate and achieve at scale. In this AI era, Slack’s mission remains making people’s work lives simpler, more pleasant, and more productive.

The Team The Slack Mobile team builds Slack's mobile experiences, from core messaging to AI and everything in between. We operate at the intersection of product innovation, mobile platform excellence, and large-scale engineering. The features and systems we build support millions of daily users and require deep investments in performance, reliability, accessibility, and user experience.

The Role We’re looking for a Senior Staff Engineer to help shape the future of Slack’s mobile product. As a Prototyping Engineer, you’ll embed as a leader on greenfield, zero-to-one initiatives. You’ll influence product and design direction through engineering work that builds and ships the first versions of newly-imagined, fully working product features. You’ll work closely with Product, Design, Backend, and fellow mobile engineers to help innovate some of the biggest new product opportunities for Slack, with experiences that are intuitive, performant, and reliable for millions of users worldwide.

What You'll Do This is a role for a self-directed, creative engineer who can operate with high velocity and strong independent judgment, combining hands-on technical leadership with broad organizational influence. We are looking for someone who can start from an ambiguous problem, no defined path, and competing priorities, and work through that to frame the problem, align stakeholders on what matters most, and move quickly from idea to working prototype to a shipped experience. You will:

• Shape the future of Slack on mobile by leading the engineering development of experiences used by millions of users every day, spanning multiple teams and the broader organization.
• Lead the most complex, ambiguous, cross-functional initiatives from early technical exploration through production rollout and long-term evolution.
• Lead feature prototyping to define the mobile user experience for Slack’s biggest opportunities.
• Partner closely with Product and Design to shape experiences that balance user needs, technical constraints, and long-term maintainability.
• Influence engineering decisions beyond your immediate team through technical leadership, product reviews, and mentorship.
• Set and evangelize best practices for mobile feature development and operational excellence across the broader engineering organization.
• Mentor senior engineers and contribute to the growth of the broader mobile engineering community within Slack.

What We're Looking For

• 10+ years of professional software engineering experience, including significant experience building complex, high-craft iOS applications at scale.

• Proven track record of moving outside of organizational boundaries to start new initiatives, prototype the path to production, and reorient the organization to support the new initiative.

• Experience working in fast-paced environments, whether at a start-up, in an incubator, or on a zero-to-one team inside a larger enterprise.

• Proven track record of leading large, ambiguous, org-spanning technical initiatives with significant business impact.

• Deep expertise in Swift framework and modern iOS development.

• Strong understanding of iOS architecture, application lifecycle, concurrency, networking, and performance optimization.

• Demonstrated ability to influence product and technical direction through expertise and collaboration, driving alignment across executive stakeholders, Engineering/Product/Design leadership, and multiple teams.

• A bias toward ownership, execution, and continuous improvement, with the judgment to prioritize the highest-leverage work across the organization.

Preferred Qualifications

• Experience with Combine, Swift Concurrency (async/await, actors), and dependency injection frameworks (e.g. Needle, Resolver).}
• Experience leading large-scale new products, features, or product transformations spanning multiple teams or the whole org.
• Experience using research, usability testing, data, and experimentation to ground decisions and uncover opportunities.
• Contributions to open source projects or the iOS community, or other external recognition of technical leadership.
• Experience building collaboration, productivity, messaging, AI, or enterprise software products.
• Excellent communication skills.
• Strong product intuition and a passion for creating exceptional user experiences.

Pursuant to the San Francisco Fair Chance Ordinance and the Los Angeles Fair Chance Initiative for Hiring, Salesforce will consider for employment qualified applicants with arrest and conviction records. In the United States, compensation offered will be determined by factors such as location, job level, job-related knowledge, skills, and experience. Certain roles may be eligible for incentive compensation, equity, and benefits. Salesforce offers a variety of benefits to help you live well including: time off programs, medical, dental, vision, mental health support, paid parental leave, life and disability insurance, 401(k), and an employee stock purchasing program. More details about company benefits can be found at the following link: https://www.salesforcebenefits.com.