Antonio Fernandez

- Built the merchant checkout platform (Next.js, React, Tailwind CSS), embedded in 400+ stores; processed over €60M/month with 99.99% uptime and <150ms response times. - Developed consumer onboarding portal (Vue 3, Pinia, Node.js) with async ID upload and status polling - reduced sign-up time from 8 to 4.3 minutes and improved KYC success by 30%. - Engineered real-time fraud scoring microservices (NestJS, Redis Streams, PostgreSQL), analyzing 300K+ transactions/day - lowered manual review workload by 28%. - Built and maintained loan scoring and risk APIs (Node.js, Express, PHP 7, PostgreSQL), supporting dynamic credit rules and historical audit trails across 3 markets. - Created GraphQL API gateway (Apollo, NestJS, Redis) to unify finance, cart, and product services-reduced client-side calls by 40% and improved API observability. - Implemented compliance admin panel (Angular 14, NestJS) for legal teams to manage onboarding rules and disclaimers-used across Sweden, Finland, and Norway. - Contributed to legacy platform modernization (.NET Core → Node.js + PHP + NestJS), migrating 3 services to TypeScript with 85% test coverage and 40ms faster response times. - Delivered features in Agile squads (Jira, GitHub Actions, Docker) with QA, PMs, and designers-shortened cycle time by 35% and improved stakeholder sign-off predictability. - Integrated Strapi CMS to manage marketing pages and legal content dynamically-enabled non-tech teams to update 50+ customer-facing assets without developer support.

- Developed core loan origination logic (Java Spring Boot, PostgreSQL), supporting ID checks, eligibility scoring, and submission flows used by 150K+ customers. - Built backend services for SEPA transfers and balance tracking (PHP 7, REST APIs), enabling same-day bank disbursements with automated reconciliation. - Created account management dashboard (React.js, Redux, SCSS) for end-users to view statements, schedule repayments, and manage support requests. - Integrated real-time alert system (Java, RabbitMQ) for transactional SMS/email messages- scaled to 2M+ monthly notifications with error monitoring. - Implemented secure authentication flow (OAuth2, JWT), reducing session-related support tickets by 40% and meeting GDPR audit standards. - Led backlog grooming and sprint planning (Jira, GitLab CI) for risk-focused APIs-reduced blocker resolution time by 35% and improved release quality.

- Developed core modules for shop management (PHP, MySQL, JavaScript), including product catalogs, inventory tools, and shipping settings. - Built and optimized the checkout engine (PHP, jQuery), improving load speed by 28% and reducing abandoned carts during peak campaigns. - Created responsive storefront templates (SCSS, Bootstrap), delivering 10+ mobile-optimized themes with built-in localization (EN, ES, FR). - Improved payment gateway reliability (REST APIs, PayPal, Stripe), cutting failed transactions by 30% through retry and fallback logic. - Worked in 2-week sprint cycles with QA and product to deliver tested shop features; supported over 40 stable production releases.