Abraham – Swift, Objective C, Android Jetpack

A mobile self-service app for telecom customers that lets users manage plans, pay bills, track usage, and handle account changes through a secure, high-availability experience.

• Architected complete GitLab CI/CD pipeline reducing deployment time from 2 hours to 15 minutes (85% reduction)
• Led migration from monolithic Objective-C to modular Swift architecture, reducing build times by 60% and enabling parallel development for 5 developers
• Designed and implemented secure device validation system (MFA) securing $50M+ monthly transactions with 99.2% success rate
• Migrated networking layer to modern Alamofire with async/await, reducing networking crashes by 35%
• Established comprehensive testing strategy increasing coverage from 20% to 72%, reducing production incidents by 30%
• Mentored 3 junior developers and conducted 100+ code reviews while maintaining 99.9% uptime for production app
• Created 13 independent modules (Foundation + Features) enabling faster feature delivery (2-week vs 4-week sprints).

Consumer sports betting and social casino app with real-time odds and live data, where users place picks and track results in a gamified mobile experience with smooth updates, robust navigation, and secure payment flows.

• Implemented GraphQL data layer with async/await and actors for live odds and scores;
• Built reusable SwiftUI components with built-in and Lottie animations;
• Implemented URL-based routing for deep links, push notifications, and universal links;
• Led integration of credit card payments and improved in-app payment flows;
• Collaborated with backend to design and refine API contracts;
• Monitored performance with Datadog and optimized slow or fragile areas of the app.

A real-time “stock market for players” app where users trade on athlete performance, track positions, and follow live odds and stats with low-latency, highly reliable in-game data.

• Led development of the Game Details experience, increasing user engagement by 14%;
• Raised unit and UI test coverage from 9% to 78%;
• Defined GraphQL API contracts for new betting and stats features;
• Built adaptable UI components shared between UIKit and SwiftUI;
• Debugged and resolved complex issues in real-time data and navigation flows;
• Worked closely with product and design to refine user journeys in core screens.

Large-scale fitness platform offering on-demand and live video classes, structured workout programs, and tracking features for millions of users worldwide through a high-quality iOS streaming app with personalized content and subscriptions.

• Optimized app startup, reducing launch time from 2.8s to 1.1s;
• Improved network performance by 37% for streaming and data loading;
• Migrated CI/CD pipelines to a more cost-effective platform, saving ~$24K/year;
• Tuned HLS/WebRTC video playback and related UI flows for reliability;
• Applied SOLID and modular architecture to keep a large codebase maintainable;
• Organized “Meet & Learn” sessions to share new tools and best practices with the team.

A regional e-commerce and loyalty platform for a major beverage brand, where a native iOS app was designed and optimized to handle high-traffic campaigns, integrate with multiple backends, and deliver fast product search and promotions to 4M+ users across multiple markets.

• Designed and built the native iOS e-commerce app for campaigns reaching 4M+ users;
• Optimized core app modules, reducing reported bugs by about 20% between releases;
• Integrated mobile apps with .NET, NodeJS, Laravel and Magento backends;
• Implemented and tuned product search using Elasticsearch and MongoDB;
• Collaborated with stakeholders to support high-traffic marketing campaigns and promotions.

This project delivered mobile and web experiences that helped end users quickly find local businesses, services, and promotional offers across multiple categories. The work emphasized upgrading an aging codebase, enhancing app stability, and making search more robust and responsive under growing traffic.

• Led migration of the iOS app from Objective-C to Swift, improving performance and reliability by 55%;
• Implemented advanced search features powered by Elasticsearch and MongoDB to improve relevance and speed of results;
• Integrated mobile apps with .NET and NodeJS services to handle listings, advertising content, and related data flows.
• Debugged and resolved production issues impacting search accuracy, navigation flows, and overall user experience;
• Profiled and fixed performance bottlenecks before major releases.