Staff iOS Engineer

About the position

About ThredUp

ThredUp is transforming resale with technology and a mission to inspire the world to think secondhand first. By making it easy to buy and sell secondhand, ThredUp has become one of the world's largest online resale platforms for apparel, shoes and accessories. Sellers love ThredUp because we make it easy to clean out their closets and unlock value for themselves or for the charity of their choice while doing good for the planet. Buyers love shopping value, premium and luxury brands all in one place, at up to 90% off estimated retail price. Our proprietary operating platform is the foundation for our managed marketplace and consists of distributed processing infrastructure, proprietary software and systems and data science expertise. With ThredUp’s Resale-as-a-Service, some of the world's leading brands and retailers are leveraging our platform to deliver customizable, scalable resale experiences to their customers. ThredUp has processed over 172 million unique secondhand items from 55,000 brands across 100 categories. By extending the life cycle of clothing, ThredUp is changing the way consumers shop and ushering in a more sustainable future for the fashion industry.

Recognized on TIME Most Influential Companies of 2023,  Digiday's WorkLife 50 2023, TIME's Best Inventions of 2022, and Lattice's People Success Awards 2022.

How You Will Make an Impact

ThredUp is transforming the way people shop—and think—about secondhand fashion. Our iOS app is the primary way millions of customers discover and purchase secondhand clothing, making it one of the most critical drivers of our business.

As a Staff iOS Engineer, you’ll take a leading role in shaping the future of this app. Reporting to the Senior Engineering Manager on the Merch Engineering team—which powers search, browse, and discovery across a constantly changing catalog of millions of unique SKUs—you’ll also provide platform-wide technical leadership. You’ll guide architectural modernization, raise the technical bar, and influence cross-team strategies that ensure our iOS app remains stable, scalable, and fast for years to come. 

We're seeking a strategic, collaborative, and communicative technical leader who's passionate about mobile platform health and adept at mentoring to raise the team's technical bar. This candidate will proactively tackle ambiguous challenges, delivering pragmatic solutions that skillfully balance immediate needs with long-term scalability.

In This Role You’ll Get To:

• Set technical direction for the iOS app, ensuring long-term stability, scalability, and performance across critical user experiences.
• Ensure robust release pipelines, testing, monitoring, and observability practices are in place across mobile teams.
• Drive architectural modernization and explore strategies to reduce redundancy and accelerate development velocity (e.g., Kotlin Multiplatform), while preserving a native-first iOS experience.
• Collaborate with cross-functional and cross-team partners to align mobile technical strategy with product goals and business priorities.
• Mentor and guide engineers across mobile teams, shaping best practices and raising the technical bar.

What We’re Looking For:

• 8+ years of professional experience building and scaling native iOS applications.
• Recognized expertise in Swift and Objective-C, with strong knowledge of UIKit and SwiftUI.
• Proven track record of leading architectural initiatives or re-architecture efforts at scale.
• Deep experience with concurrency, memory management, performance optimization, and system design for mobile applications.
• Experience driving cross-team technical projects, influencing technical strategy beyond a single product area.
• Proven ability to mentor and grow engineers, shaping engineering practices across teams.
• A product mindset: able to connect technical decisions to user experience and business outcomes.
• Curiosity and excitement about leveraging AI to accelerate mobile development (e.g., code generation, testing, performance optimization).
• Familiarity with Android (Kotlin/Java) and an interest in collaborating with Android engineers to ensure platform parity is a plus.
• Exposure to Kotlin Multiplatform or other shared-code strategies, along with experience in consumer-facing e-commerce, search, or other high-scale user engagement applications is a plus.

At ThredUp, your base pay is one part of your total compensation package. This role pays between $225,000 and $240,000, and your actual base pay will depend on your skills, qualifications, experience, and location.

Many ThredUp employees also have the opportunity to own shares of ThredUp stock, ThredUp employees are eligible for discretionary restricted stock unit awards, as well as a discount when purchasing ThredUp stock if voluntarily participating in ThredUp’s Employee Stock Purchase Plan. Subject to eligibility requirements, you’ll also receive other benefits: Comprehensive medical & dental coverage, vision, 401k, life and disability insurance.
 

This role is not eligible for visa sponsorship.

What We Offer:

• 4-day work week, with Fridays off

• Hybrid work environment: 3 days in the office and 1 day remote each week

• Competitive salary (we leverage market data)

• Many ThredUp employees also have the opportunity to own shares of ThredUp stock and are eligible for discretionary restricted stock unit awards

• Employee stock purchase plan

• Flexible PTO (take the time you need) + 13 company holidays

• Paid Sabbatical after 3 years of full time employment

• Generous paid parental leave for new mothers and fathers

• Medical, dental, vision, 401k, life and disability insurance offered

• We live by our Core Values of Transparency, SpeakingUP, Thinking Big, Infinite Learning, Influencing Outcomes & Seeking the Truth

We believe diversity, inclusion and belonging is key for our team

At ThredUp, our mission has been built on extending the lives of millions of unique clothing items. Much like our inventory, we are proud to have fostered a workplace that is one-of-a-kind. As a company focused on diversity, inclusion and belonging, we are committed to ensuring our employees are comfortable bringing their authentic selves to work every day. A unique perspective is critical to solving complex problems and inspiring a new generation to think secondhand first. Be you.

If you are a candidate with a disability and have a reasonable accommodation request for the job application process, please email disabilitysupport@ThredUp.com the specific details of your disability related accommodation request. This email address is reserved for candidates with disabilities only. General application inquiries will not receive a response.

Place of work