# Enmanuel Leon **Senior Fullstack Engineer | Distributed Systems & Cloud** Valencia, Venezuela (Remote · CET / EST Timezones) | Citizenship: Italian (EU), Venezuelan Email: [contact@enmanuel-leon.com](mailto:contact@enmanuel-leon.com) | LinkedIn: [linkedin.com/in/enmanuel-leon-48b11714b](https://www.linkedin.com/in/enmanuel-leon-48b11714b/) | GitHub: [github.com/enmanuel-leon](https://github.com/enmanuel-leon) | Web: [enmanuel-leon.com](https://enmanuel-leon.com) Languages: Spanish (Native), English (Professional Technical Working / B1) --- ## Professional Summary Computer Engineer with 6+ years of experience in mission-critical software engineering, specializing in distributed architectures, agentic systems, and transactional platforms. Proven track record designing high-availability asynchronous services with **TypeScript, Node.js (Fastify/Express), and Python** deployed across cloud infrastructure (**AWS / GCP**). Expert in architecting high-throughput document processing engines, secure M2M orchestration for isolated VPC environments, and developing payment gateway integrations across heterogeneous API ecosystems (REST, GraphQL, SOAP) backed by relational databases (MySQL, PostgreSQL) and high-concurrency message queues (**Redis, BullMQ, SQS**). --- ## Technical Skills - **Backend & Architecture:** Node.js (Fastify, Express), Python (FastAPI), Prisma, Zod, Microservices, Agentic Architecture (Multi-Agent), REST, GraphQL, SOAP, Event-Driven Architecture (EDA), M2M Communication, Idempotency & Circuit Breakers - **Cloud, Networking & DevOps:** AWS (ECS, Lambda, RDS, S3, SQS, CloudWatch, IAM, CloudFormation), GCP (Cloud Run), Docker, Docker Compose, CI/CD (GitHub Actions), NGINX, Linux, VPC Isolation - **Databases & Messaging:** MySQL, PostgreSQL, MongoDB, Redis, BullMQ, AWS SQS, Row-Level Security (RLS), RabbitMQ - **Applied AI & Automation:** Agentic Architecture (Multi-Agent), Agent-Assisted Engineering (SDLC), LLM Integrations (OpenAI, Anthropic APIs), Asynchronous Artifact Generation, Agent Orchestration, RAG Pipelines & Guardrails, Prompt Engineering, Tool Use & Function Calling - **Frontend & Mobile:** React, Next.js, Vite, React Native (Cross-platform iOS/Android), TypeScript, JavaScript (ES6+), HTML5, Tailwind CSS - **Testing, Quality & Security:** Vitest, Jest, Datadog, Sentry, CloudWatch, OWASP, CORS, TDD --- ## Professional Experience ### Fullstack Developer (AI & Core Systems) | Entropy Systems | Barcelona, Spain (Remote) *April 2024 - Present* - **Significantly reduced processing time** for complex regulatory reports by designing and deploying a distributed asynchronous document and artifact generation engine using Fastify and Python, orchestrated with BullMQ and Redis queues. - **Co-designed the agentic system architecture** and architected the backend layer of the core AI tooling platform (multi-agent orchestration, tool calling, and autonomous execution workflows), delivering high-concurrency multi-instance scaling and low-latency Machine-to-Machine (M2M) communication via decoupled APIs and token-based authentication. - **Designed a periodic asynchronous synchronization engine** using distributed crons and background workers that securely interconnects isolated customer VPC environments with the central core platform, ensuring data consistency without exposing public endpoints. - **Accelerated engineering and development cycles** by integrating agentic architectures and autonomous coding agents into the workflow (SDLC), optimizing deep refactoring, rapid prototyping, and automated test coverage while upholding strict production quality standards. - **Steered engineering standards and architectural decision records** (RFCs/ADRs), cutting technical debt and accelerating cross-service integration across engineering peers. - **Operated distributed microservices across AWS and GCP with high availability**, containerizing services in Docker and implementing CI/CD pipelines for automated continuous deployments backed by real-time observability in Sentry and CloudWatch. ### Software & Mobile Engineer (Independent Consultant / Part-time Contractor) | Fintech Scale-up (Credit & Financial Platform · NDA) *July 2025 - July 2026* - **Engineered the end-to-end cross-platform mobile architecture** (iOS and Android) using React Native and TypeScript for a digital financial and credit origination platform, defining technical specifications and cloud integrations. - **Architected scalable cloud data infrastructure and security controls**, implementing robust authentication flows and fine-grained Row-Level Security (RLS) policies to protect sensitive credit records and financial contracts. - **Optimized mobile application performance and network resilience**, streamlining startup load times and securing reliable offline persistence for credit applications and operations in low-connectivity environments. ### Fullstack Developer | Interfell - ePayco | Remote *June 2021 - April 2024* - **Maintained high availability across critical payment gateway services** for merchants and corporate partners by engineering and maintaining transactional microservices in Node.js (Express) and TypeScript on MySQL, while integrating auxiliary services in PHP (Lumen). - **Engineered resilience and idempotency controls** for critical financial transactions, implementing Circuit Breakers, Rate Limiting, and exponential backoff retries to guarantee zero duplicate charges and isolate external banking failures. - **Led technical payment gateway integrations** for corporate merchants and partners, orchestrating transaction lifecycles between responsive React web applications and backend services connected across REST, GraphQL, and legacy SOAP APIs. - **Significantly reduced transaction processing latency** by optimizing complex MySQL queries, offloading asynchronous background tasks with AWS SQS queues, and refactoring critical API endpoint handlers. - **Accelerated production issue resolution and improved system reliability** by establishing reproducible Docker environments, comprehensive automated testing suites in Jest, and proactive anomaly monitoring via Datadog and Sentry. ### Systems Analyst / Software Developer | Intelix Synergy, C.A. | Valencia, Venezuela *March 2020 - June 2021* - **Boosted business process efficiency** by delivering 3 modular internal management systems in JavaScript, Node.js, and Python used daily across business operations. - **Ensured continuous high availability (zero unplanned downtime)** by administering production Linux servers configured with NGINX reverse proxies, load balancing, and SSL/TLS security policies. - **Decreased developer onboarding time** by authoring comprehensive OpenAPI/Swagger specifications, interactive endpoint documentation, and modular architecture blueprints. --- ## Education ### Bachelor of Science in Computer Engineering (5-year Degree Equivalent / 10 Semesters) **Universidad José Antonio Páez** | Valencia, Venezuela *2017 - 2020* *Accelerated continuous 10-semester curriculum. Core studies in distributed systems, relational databases, software engineering, and computer architecture.* --- ## Additional Information - **Areas of Specialization:** Distributed Systems Architecture, Multi-Cloud (AWS · GCP), Applied AI Automation, Payment Gateways & Fintech Integrations. - **Portfolio & Code:** [enmanuel-leon.com](https://enmanuel-leon.com) | [github.com/enmanuel-leon](https://github.com/enmanuel-leon)