Alejandro Portillo Guerrero

FIFA+

Nov 2024 – Now

• Reduced crash rates by 80% through deep refactoring of legacy components and adoption of Swift async/await.
• Result: 99.9% app stability during global tournaments with millions of concurrent users.
• Led the integration of Airship push notifications, enabling delivery of personalized, event-driven content to fans worldwide and significantly improving user engagement during major competitions.

Hablalo – Asteroid Technologies

June 2024 – Oct 2024

• Led the complete redesign of the iOS app with SwiftUI, delivering major improvements in performance, accessibility, and UX.
• Replaced Firebase deep linking with Branch, ensuring reliable navigation across 100k+ active sessions.
• Built a modular QR code system enabling business model pivots without reprinting costs, reducing operational overhead by 70%.

• Owned iOS development of a new SaaS platform for enterprise workflow orchestration.
• Implemented a scalable architecture (SwiftUI + MVVM-C + DDD), laying foundations for multi-team development.
• Developed SDKs shared across Inditex teams, increasing velocity of new feature delivery.
• Achieved >90% automated test coverage (unit, snapshot, mutation, and E2E), improving release confidence and reducing regression bugs.

Ola Invierte

Tech Lead

Sept 2021 – May 2023

• Owned the entire iOS lifecycle for a brokerage and crypto investment platform serving Spanish-speaking users across LATAM and the U.S.
• Delivered app from MVP to production with fully integrated KYC (Onfido), Vanguard Robo-Advisor, and real-time portfolio management.
• Designed scalable communication between mobile and backend services, enabling rapid expansion into new business lines (crypto + managed funds).
• Built internal tools including a Figma-to-React KYB generator, streamlining onboarding and cutting design–dev handoff time by 40%.   

• Led development of AI-powered speech coach (iOS & Android), scaling from MVP to 300k+ downloads worldwide.
• Integrated Core ML for real-time speech analysis, enabling on-device feedback without cloud latency.
• Built a macOS widget with AI-driven insights, diversifying product offering.

As Engineering Manager / Product Manager (Nov 2018 - Dec 2020):

• Directed a cross-functional team of 6 engineers, combining analytics, user research, and roadmap prioritization.
• Boosted product revenue by 50% in six months through iterative feature launches and growth experiments.
• Built a Figma plugin that auto-generated SwiftUI & React components, streamlining cross-platform development.
• Designed automated test pipelines for generated UI, improving reliability and reducing manual QA workload.

• Designed and led development of a real-time salon booking platform, integrating location-based services and dynamic scheduling.
• Fully developed iOS app (Swift, MVVM) and its widgets, while also managing backend integration (NodeJS).
• Improved platform adoption by designing highly scalable architecture for mobile + back-office.

• Migrated one of the industry’s leading betting apps to Swift, improving maintainability and performance.
• Built internal SDKs reused across multiple William Hill apps, standardizing functionality and reducing duplicated effort.
• Collaborated with cross-functional web teams, implementing Swift/Web bridging to integrate responsive features into native iOS apps.   

• Led iOS development of BetVictor’s main app, scaling performance and reliability.
• Improved app store rating from 3★ to 4.5★ through UX improvements and stability enhancements.  

• Development of app to prevent occupational hazards for Professional Associations of Labour Relations of Madrid

• Development of their two main apps: Cliqs and Moodcup where we got over 50.000 downloads

• Developed an iOS application to extend the functionality of the Spanish Electronic Health Record (EHR) System, enabling smoother data access and improving overall healthcare provider efficiency.