Senior iOS Build System Engineer, Mobile Developer Experience

  • Full-time

Company Description

Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams — People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more — provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.

Job Description

Mobile Developer Experience (MDX) builds all necessary infrastructure and tools to ensure Square's mobile development can continue to be fast and efficient at scale. This is a high force multiplier team aiming to enhance the developer experience for all iOS developers at Square. Our focus is on improving both the local IDE and CI experience when working within our massive and modularized monorepo codebase. We're betting heavily on the future of Bazel. We've already made a 4x improvement on compilation speed and 2x improvement in CI turnaround, but there is still a lot more room for improvement. We do our work in the open, on GitHub, and progress can be seen in the bazel-ios project on GitHub. You'll be part of a team on the cutting edge of iOS build engineering that contributes fixes and improvements to Bazel, maintains Xcode integration, delivers Bazel Remote Execution, and maintains a CDN based remote caching system.

You Will: 

  • Accelerate our delivery of a fast and efficient developer experience with Bazel
  • Amplify the efficiency of our mobile developers to develop, test, and release apps to our merchants
  • Identify and fix performance bottlenecks in the development experience with novel solutions
  • Debug and fix issues in large C++ and Java projects like clang, llvm, swift, lldb and Bazel
  • Help determine the scope and the priorities of the team by identifying opportunities to decrease build times, reduce system complexity, and improve the developer experience
  • Optimize the performance, and usability of our build tooling
  • Oversee the success of our team's projects, and achieve quantifiable results


  • Passionate about accelerating the development velocity of other engineers and improving their developer experience as part of a larger team.
  • Knowledge of build systems (preferably Bazel/Blaze/Buck)
  • Knowledge of the roles that tools such as xcodebuild, clang, swift, ld, actool, ibtool, and codesign play in the process of generating build/test artifacts
  • Experience supporting build and CI systems infrastructure at scale
  • First hand experience building Apple apps in Swift or Objective-C (preferably both)
  • Excellent software engineering knowledge and the ability to provide technical mentorship and guidance
  • Experience with reverse engineering Xcode, macOS, or iOS software

Additional Information

Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate’s starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.

Zone A: USD $202,500 - USD $247,500
Zone B: USD $192,400 - USD $235,200
Zone C: USD $182,300 - USD $222,800
Zone D: USD $172,200 - USD $210,400

To find a location’s zone designation, please refer to this resource. If a location of interest is not listed, please speak with a recruiter for additional information. 

Benefits include the following:

  • Healthcare coverage
  • Retirement Plans including company match 
  • Employee Stock Purchase Program
  • Wellness programs, including access to mental health, 1:1 financial planners, and a monthly wellness allowance 
  • Paid parental and caregiving leave
  • Paid time off
  • Learning and Development resources
  • Paid Life insurance, AD&D. and disability benefits 
  • Perks such as WFH reimbursements and free access to caregiving, legal, and discounted resources 

This role is also eligible to participate in Block's equity plan subject to the terms of the applicable plans and policies, and may be eligible for a sign-on bonus. Sales roles may be eligible to participate in a commission plan subject to the terms of the applicable plans and policies. Pay and benefits are subject to change at any time, consistent with the terms of any applicable compensation or benefit plans.

We’re working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is a proud equal opportunity employer. We work hard to evaluate all employees and job applicants consistently, without regard to race, color, religion, gender, national origin, age, disability, pregnancy, gender expression or identity, sexual orientation, citizenship, or any other legally protected class. 

We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we’re doing to build a workplace that is fair and square? Check out our I+D page

Additionally, we consider qualified applicants with criminal histories for employment on our team, and always assess candidates on an individualized basis.

Block, Inc. (NYSE: SQ) is a global technology company with a focus on financial services. Made up of Square, Cash App, Spiral, TIDAL, and TBD, we build tools to help more people access the economy. Square helps sellers run and grow their businesses with its integrated ecosystem of commerce solutions, business software, and banking services. With Cash App, anyone can easily send, spend, or invest their money in stocks or Bitcoin. Spiral (formerly Square Crypto) builds and funds free, open-source Bitcoin projects. Artists use TIDAL to help them succeed as entrepreneurs and connect more deeply with fans. TBD is building an open developer platform to make it easier to access Bitcoin and other blockchain technologies without having to go through an institution.

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