Open to opportunities

Oliverio Alonso

@oliverioalonso

Message

Full-Stack Engineering Lead driving scalable platforms and mentoring teams to ship end-to-end.

Spain

Message

What I'm looking for

I’m looking for a product-minded engineering environment where I can own architecture and migrations, stay hands-on, and lead teams through end-to-end delivery—combining platform reliability, great DX, and AI-enabled innovation.

I’m a Full-Stack Engineering Lead with 12+ years building high-performance teams and scalable systems. I lead end-to-end delivery, from architecture and migrations to production readiness and continuous improvement.

In recent roles, I’ve owned cross-team work across frontend, backend, infra, and AI—shipping end-to-end and modernizing platforms through micro-frontend and serverless migrations. I’ve also built and evolved observability, reduced MTTR, and strengthened reliability through pragmatic engineering and testing.

I’m currently founding CrimeMapX.com while maintaining hands-on technical leadership. My focus blends platform engineering with product thinking—architecting microservices, driving AI initiatives (RAG/vector search), and mentoring 20+ engineers toward senior-level impact.

Experience

Work history, roles, and key accomplishments

Current

Staff Software Engineer

Current

UserTesting.com

Jan 2026 - Present (6 months)

Own cross-team end-to-end work across frontend, backend, infra, and AI. Led micro-frontend migrations, modernized serverless deployment pipelines, and drove AI initiatives using OpenSpec, agents/skills, and token-usage optimization.

React Next.js TypeScript NestJS GraphQL gRPC AWS Lambda Aurora MongoDB Bedrock Kafka Terraform Helm Datadog OpenSpec MCP Servers Agent End To End Testing

Founder

CrimeMapX.com

Jun 2025 - May 2026 (11 months)

Built and operated a full-stack crime analytics platform with React/Next.js frontend and a Python/FastAPI backend. Implemented SSR/ISR strategies, processed large-scale records with Supabase, and delivered RAG-based semantic search with vector similarity using pgvector.

Next.js React ISR Python fastAPI Supabase PostgreSQL Pgvector OpenAI Models Vector Similarity Retrieval Augmented Generation (RAG) Systems Deno Edge Functions

Lead Software Engineer

90Poe.io

Nov 2022 - Dec 2025 (3 years 1 month)

Architected and led delivery of microservices using Go and Node.js/NestJS, including event-driven processing with Kafka across 15+ services. Improved system performance, observability, and deployment efficiency, including a monolith-to-microservices migration.

Go Node NestJS Kafka Event Driven Architecture PostgreSQL Connection Pooling Read Replicas Datadog Sentry Microservices Observability Migration

Principal Staff Software Engineer

0XA Tech

Jul 2022 - Nov 2022 (4 months)

Built a full-stack Web3 crypto platform with advanced SSR/hydration SEO optimization on the frontend and Node.js/Express on the backend. Integrated Ethers.js for smart contract interactions and implemented indexing services to sync blockchain events into PostgreSQL.

Next.js React Node Express Web3 Solidity Smart Contracts PostgreSQL Uptime and Transaction Handling

Senior Software Engineer

Casebook PBC

May 2021 - Jul 2022 (1 year 2 months)

Designed and implemented a GraphQL BFF using Node.js/TypeScript/Express with the CQRS pattern to separate read and write operations. Built PostgreSQL schemas with indexing and materialized views, and developed Python/Django REST endpoints for reporting and export.

GraphQL BFF Node.Js Development TypeScript Express CQRS PostgreSQL Indexing Materialized Views Connection Pooling Query Optimization Python Caching

Senior Software Engineer

Feedr

May 2020 - May 2021 (1 year)

Built a Node.js/TypeScript/Express backend with GraphQL, implementing CQRS for an office food ordering platform. Improved throughput by separating read-heavy menu queries from write-heavy order commands and added Redis caching to reduce peak load.

Node TypeScript Express GraphQL CQRS PostgreSQL Redis

Senior JS Engineer

Spotahome

Feb 2019 - Apr 2020 (1 year 2 months)

Architected microservices backend using Node.js/TypeScript with domain-driven design (DDD) and event sourcing, including MongoDB-based event storage for audit and temporal queries. Built a GraphQL BFF consolidating microservices, and led a team of 6 to adopt hexagonal architecture and testing standards.