Staff iOS Engineer, Foundation

blockBay Area, CA, United States of Americagreenhouse
Posted Date:

September 29, 2025

Employment Type:

Not specified

Work Arrangement:

On-site/Hybrid

Skills & Technologies

10527 Engineering - Squarepreferred

Job Description

Since we opened our doors in 2009, the world of commerce has evolved immensely, and so has Square. After enabling anyone to take payments and never miss a sale, we saw sellers stymied by disparate, outmoded products and tools that wouldn't work together.

So we expanded into software and started building integrated, omnichannel solutions – to help sellers sell online, manage inventory, offer buy now, pay later functionality, book appointments, engage loyal buyers, and hire and pay staff. Across it all, we've embedded financial services tools at the point of sale, so merchants can access a business loan and manage their cash flow in one place. Afterpay furthers our goal to provide omnichannel tools that unlock meaningful value and growth, enabling sellers to capture the next generation shopper, increase order sizes, and compete at a larger scale.

Today, we are a partner to sellers of all sizes – large, enterprise-scale businesses with complex operations, sellers just starting, as well as merchants who began selling with Square and have grown larger over time. As our sellers grow, so do our solutions. There is a massive opportunity in front of us. We're building a significant, meaningful, and lasting business, and we are helping sellers worldwide do the same.

The Role

Foundation iOS builds, maintains, and enables platform-level capabilities, architectural foundations, and developer tools that keep Square's iOS apps performant, reliable, observable, and scalable. This includes our flagship product Point of Sale and all of Square's seller-facing iOS applications.

We're the backbone that enables Square's 150+ iOS engineers to build and ship features efficiently and reliably. Our mandate spans the core infrastructure that powers Square's mobile ecosystem: from state management and dependency injection to networking primitives, data persistence, testing frameworks, and the modular architecture that enables distributed development across multiple teams.

Why? Building reliable, performance mobile applications at Square's scale requires robust foundational systems. Foundation iOS ensures that product engineers have the architectural primitives, tools, and frameworks they need to deliver high-quality experiences to Square's sellers without reinventing the wheel.

Our core systems includes:

    • Workflow: Square's state management framework
    • Bazel: Our build system
    • Dependency injection system
    • Testing systems: Unit testing, UI automation, snapshot frameworks Data Persistence
    • Observability: Frameworks and dashboards to monitor our applications' performance & reliability

We work closely with peer teams like UI Systems, Release Engineering, Mobile Developer Experience, and all product engineering teams.

As a staff engineer on Foundation iOS, you'll work closely with Foundation leads and technical leads across Square to set technical direction, drive architectural decisions, and evangelize foundational improvements that benefit the entire iOS organization. You'll be expected to identify system issues that span team boundaries and drive cross-functional solutions to completion.

You Will

    • Build and evolve core architectural frameworks that power Square's iOS applications, including state management, dependency injection, networking primitives, data persistence layers, observability frameworks, and testing systems.
    • Drive technical excellence across Square's iOS codebase by identifying performance bottlenecks, reliability issues, and developer productivity pain points, then building solutions that scale across hundreds of engineers.
    • Lead cross-team initiatives such as iOS version upgrades, application architecture improvements, memory leak remediation, and migration from legacy systems to modern frameworks.
    • Partner with product engineering teams to embed foundational improvements, provide technical guidance, and ensure smooth adoption of new frameworks and tools.
    • Maintain critical infrastructure including our module structure and code generation tools.
    • Drive performance and reliability improvements by building automated testing systems, observability tools, and architectural changes that prevent regressions and improve app quality.
    • Mentor and enable other engineers through documentation, education, technical reviews, and fostering communities of practice around mobile development best practices.

You Have

  • 12+ years iOS devel