Knot · 20 hours ago
Senior iOS Engineer
New York, NY
Full-time
Hybrid
Senior LevelKnot is a company focused on empowering connected merchant and banking experiences. They are seeking a Senior iOS Engineer to shape the architecture and performance of their SDK, working across its entire lifecycle and collaborating with product and engineering teams.
Developer APIsFinTech
Responsibilities
Lead and contribute to the architecture, design, and optimization of the iOS SDK
Profile, debug, and improve memory usage, CPU consumption, concurrency, and overall runtime efficiency
Design stable, predictable public APIs and produce documentation that supports developers integrating our SDK
Strengthen test coverage with unit tests, UI automation, integration testing, and performance testing
Co-own the mobile CI/CD workflows that ensure safe, reliable, and repeatable releases
Investigate production issues with attention to detail and implement long-term safeguards
Advocate internally and externally for best practices around integration, performance, and reliability
Participate in cross-team technical planning and represent the platform’s needs
Evangelize the SDK and help educate teams on its capabilities and usage
Contribute to building an engineering culture rooted in clarity, ownership, and thoughtful design
Qualification
Required
Strong debugging skills and proficiency with native profiling tools
Deep understanding of memory allocation, leaks, CPU usage, and asynchronous patterns
Experience building asynchronous and multithreaded architectures
Ability to design, validate, and document public SDK APIs
Strong unit testing mindset and experience uncovering failure modes and edge cases
Familiarity with mobile CI/CD pipelines and the desire to improve them
Comfortable executing thorough QA validation prior to releases
Clear and effective communication with cross-functional teams
Experience writing and debugging UI automation tests
Familiarity with feature flagging and controlled rollout strategies
Deep experience with WKWebView including navigation, messaging, resource handling, and hybrid debugging
Proficiency with Swift and Swift Concurrency
Experience with ARC, Instruments, and iOS frameworks
Experience building and maintaining frameworks or Swift Packages
Familiarity with Xcode build tooling and performance optimization
Benefits
100% medical, dental, and vision insurance coverage for you and your dependents (U.S.)
Unlimited PTO
Parental leave
Beautiful NYC office in the heart of Flatiron
Herman Miller Aeron desk chair
Food (snacks, frequent lunches & often dinner for those working late)
Company
Knot
The merchant connectivity platform. Switch cards-on-file in online merchant accounts.
Founded in 2019
11-50 employees
H1B Sponsorship
Knot has a track record of offering H1B sponsorships. Please note that this does not
guarantee sponsorship for this specific role. Below presents additional info for your
reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2022 (2)
Funding
Current Stage
Early StageTotal Funding
$13MKey Investors
Nava VenturesGiant Ventures
2024-09-05Series A
2023-08-03Series A· $10M
2021-02-02Seed· $3M
Leadership Team
Rory O'Reilly
CEO and Co-Founder
Recent News
2025-12-13
2025-12-11
Tech in Asia
2025-12-10
Company data provided by crunchbase