Lucas D.

Solutions Architect | Java/Spring · AWS · Kubernetes · Fintech Overview I design and build backend platforms for fintech, and keep them running in production. 20+ years with Java, the last few in fintech. I'm currently Solutions Architect & Tech Lead at Unnotech, a Brazilian credit fintech, where I created the lending platform and lead it end to end: domain and API design, backend services, AWS infrastructure, CI/CD and observability. Before that I was a Senior Software Engineer on Bitso's Identity & Access Management team (a Latin American crypto exchange), working on authentication and authorization with Keycloak. What I can do for you: • Backend architecture & development: modern Java (21–25) and Spring Boot microservices, event-driven systems (SQS/SNS, Redis Streams, outbox), partner-facing REST APIs, PostgreSQL. • Integrations: 15+ bank and fintech APIs integrated in production, with async flows, webhooks, idempotency, rate limiting and retries. • Identity & access: Keycloak (custom authentication flows, running on Kubernetes), OAuth2 / OpenID Connect, Spring Security. • Cloud & DevOps: AWS (EKS, RDS, ElastiCache, SQS/SNS, Lambda, API Gateway) with Terraform, Kubernetes + Helm + ArgoCD (GitOps), blue/green deployments, GitHub Actions. • Observability: OpenTelemetry, Prometheus, Grafana, Loki, Tempo, alerting. • AI in practice: LLM features and engineering automation with Claude on AWS Bedrock. Recent work: • A multi-bank lending API: partners integrate once, and the platform quotes several banks in parallel and returns multiple offers. • A cost-aware credit rules engine that runs cheap checks before paid credit-bureau queries. • A do-not-contact compliance service answering lookups in ~1 ms on DuckDB. • A complete AWS platform as code: EKS, Karpenter, Istio, GitOps, production and staging environments. How I work: I start from the business problem, write a short design doc, deliver in small increments you can see working, and leave code, infrastructure and documentation your team can own. Comfortable leading a team or working as a hands-on individual contributor. Based in Curitiba, Brazil (UTC−3), with good overlap with US time zones. I work in English and Portuguese. ## Skills (Upwork tags) Java · Spring Boot · Microservices · API Development · AWS · Kubernetes · Terraform · Keycloak · OAuth · PostgreSQL · DevOps · Fintech