<p>Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. <span style="color: rgba(0, 0, 0, 0.9); font-family: -apple-system, system-ui, 'system-ui', 'Segoe UI', Roboto, 'Helvetica Neue', 'Fira Sans', Ubuntu, Oxygen, 'Oxygen Sans', Cantarell, 'Droid Sans', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Lucida Grande', Helvetica, Arial, sans-serif; font-size: 14px; font-style: normal; font-weight: 400; letter-spacing: normal; text-align: start; word-spacing: 0px; white-space: normal; display: inline !important; float: none;">💫</span></p> <p>Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. <span style="color: rgba(0, 0, 0, 0.9); font-family: -apple-system, system-ui, 'system-ui', 'Segoe UI', Roboto, 'Helvetica Neue', 'Fira Sans', Ubuntu, Oxygen, 'Oxygen Sans', Cantarell, 'Droid Sans', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Lucida Grande', Helvetica, Arial, sans-serif; font-size: 14px; font-style: normal; font-weight: 400; letter-spacing: normal; text-align: start; word-spacing: 0px; white-space: normal; display: inline !important; float: none;">🌱 </span>Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.</p> <p> </p> <h3><strong>The Challenge 🧩</strong></h3> <p>You will join the <strong>iOS Platform team</strong>, the team that sets the technical direction for iOS at Wallapop. Our users are primarily other engineers, and our mission is to supercharge their daily productivity while defending the quality and performance of our app. We own the build system, developer tooling, module architecture, testing infrastructure, and observability foundations that everyone else ships on top of.</p> <p> </p> <p>We work on a <strong>10+ year-old codebase used by millions of people</strong> (~115 modules and over 20,000 Swift files), where every second shaved off a build is multiplied across the entire engineering chapter.</p> <p> </p> <p>In this role, <strong>you will own app performance as a product metric</strong>—from launch time and responsiveness to memory footprint and app size. As an iOS Platform Engineer, you will have company-wide scope, acting as an architect, mentoring engineers across the chapter, and tackling our most complex technical challenges.</p> <h3><strong>Our tech stack:</strong></h3> <ul> <li><strong>Build & Infra:</strong> Bazel-based build system with remote caching/execution, paired with <em>Tente</em> (our in-house Go CLI and BSP server to support IDEs like VSCode, Neovim).</li> <li><strong>CI/CD & Testing:</strong> High-scale pipelines on Bitrise, a robust testing pyramid featuring Quick/Nimble, ~9,000 snapshot references, and Maestro E2E flows in the cloud.</li> <li><strong>Architecture & UI:</strong> Simplified, TCA-inspired architecture built on RxSwift, custom dependency injection, UIKit, SwiftUI, and our <em>Conchita</em> design system.</li> <li><strong>Observability & AI:</strong> Deep tracing via Sentry and OpenTelemetry, automated PR quality gates, and AI-assisted workflows (AI code-review bot and repo-native agents).</li> </ul> <p> </p> <h3><strong>What You Will Do 👇</strong></h3> <ul> <li>Keep builds fast, hermetic, and understandable as the codebase and the team grow.</li> <li>Build developer tooling that engineers actually enjoy using, and measure whether it moves the needle on daily productivity.</li> <li>Maintain a healthy, fast, and trustworthy CI/CD and release pipeline, from PR checks to the App Store.</li> <li>Define, measure, and deliver on user-facing performance goals: app launch time, responsiveness, rendering smoothness, memory footprint, and crash-free rate.</li> <li>Profile with Instruments on real devices and optimize at the binary level (main-thread startup work, dyld and static initializers, binary layout, and framework count).</li> <li>Own the observability stack (Sentry/OpenTelemetry) to provide tracing and dashboards that engineers trust, and set up automated guardrails in CI to block regressions.</li> <li>Set the module boundaries and structural design of the app, leading migrations that cross a hundred modules without freezing feature delivery.</li> <li>Design and lead our structural architectural evolution, including the transition from RxSwift toward modern Swift Concurrency (async/await, actors, Sendable).</li> <li>Partner with feature teams as an enabler: unblock them, document the paths, and make "the right thing the easy thing" to do.</li> <li>Drive technical decisions with chapter-wide impact through RFCs and hands-on prototypes, aligning product, design, and backend stakeholders.</li> <li>Mentor iOS engineers across the company, raising the technical ceiling of the entire engineering chapter.</li> </ul> <p> </p> <h3><strong>What We’re Looking For 🔎</strong></h3> <ul> <li>Extensive experience designing, developing, and scaling iOS applications in Swift.</li> <li>A proven track record of working in large, highly modular codebases, and comfort navigating and refactoring code you did not write.</li> <li>A platform mindset: treating other engineers as your users, measuring impact, and demonstrating a passion for developer experience.</li> <li>Deep, hands-on experience with mobile performance profiling (Instruments) and a strong understanding of what makes an app fast and stable.</li> <li>Strong autonomy and pragmatism, with the ability to scope massive technical migrations into safe, incremental, and highly strategic steps.</li> <li>Excellent communication a