Lázaro O'Farrill
Senior Backend & Systems Engineer Wrocław, Poland
[email protected] | [email protected] | lazaroofarrill.com | github.com/lazaroofarrill
Status: Based in Wrocław, Poland (Eligible for EU Blue Card Transfer / Local Employment Contract)
Professional Summary
Senior Backend and Systems Engineer with 6+ years of experience building, scaling, and optimizing high-concurrency distributed systems, real-time data streaming architectures, and low-level integrations. Proven track record of eliminating architectural bloat, cutting system latency by up to 600ms, scaling rendering throughput by 10x, and reducing cloud infrastructure spend by 50%. Deep technical expertise spanning from event-driven microservices (Go, Kafka, Redis) to bare-metal embedded firmware (C/C++, Modbus, RTOS).
Core Technical Skills
- Languages: Go, TypeScript, JavaScript, Kotlin, Java, Rust, C/C++, Python, SQL
- Data & Streaming: Kafka, Redis, Elasticsearch, PostgreSQL, DuckDB, MySQL, SQLite, Change Data Capture (CDC), OLAP
- Backend & Distributed Systems: Node.js, NestJS, AWS (Lambda, ECS, S3), Docker, Terraform, Event-Driven Architecture, Microservices
- Low-Level & Infrastructure: WebHID, Modbus RTU, I2C/SPI/UART, Zephyr RTOS, ROS, Linux/POSIX
- Observability & Tooling: Grafana, Prometheus, Loki, ELK Stack, Compose Multiplatform
- Enterprise Integrations: Odoo, Salesforce, Stripe
Professional Experience
Senior Software Engineer / Backend Lead | DSpot (Poland)
May 2022 – Present
- Real-Time Data Streaming: Built a high-throughput sports data ingestion pipeline using Go and Redis, applying on-the-fly transformations, CDC reactive updates, and real-time OLAP workloads for live game scoring under strict latency constraints.
- Event-Driven Integration Pipeline: Architected an asynchronous event-streaming pipeline integrating Salesforce, Kafka, AWS Lambda, and Elasticsearch, optimizing API rate limits and network bandwidth for materialized downstream search.
- Performance & Scale Optimization: Redesigned high-concurrency, auto-scalable rendering pipelines using Node.js, Redis, and Docker, increasing throughput by 10x (10 to 100 renders/hour) and slashing unrecoverable errors from 10% to 0.01%.
- Distributed System Reliability: Resolved worker failure cascades and dropped tasks across distributed compute nodes, implementing fair job distribution and backpressure recovery mechanisms.
- Hardware & Driver Integration: Implemented low-level WebHID device drivers in TypeScript / C++ for specialized bi-directional hardware communication.
- Developer Tooling & Agentic AI: Developed custom JetBrains IDE plugins in Kotlin using Compose Multiplatform, embedding internal developer workflows and agentic capabilities directly into developer environments.
Backend Software Engineer | Guajiritos SRL (Havana, Cuba)
July 2021 – May 2022
- Latency & Cost Optimization: Refactored a distributed microservices network into an optimized core architecture, cutting average system latency by 600ms and reducing server operating costs by 50%.
- Transactional Scalability: Scaled high-concurrency transactional database layers (PostgreSQL, Redis, Node.js) for global distribution systems (GDS) and e-commerce platforms handling high-volume booking traffic.
- Edge & Offline Resilience: Designed resilient, offline-first backend synchronization protocols for distributed point-of-sale (POS) and inventory management terminals.
Co-Founder & Lead Systems Engineer | Espoleta Technologies (Havana, Cuba)
January 2021 – Present
- Low-Power Distributed Edge Architecture: Architected firmware and backend telemetry pipelines for VORTICE (autonomous environmental monitoring stations), optimizing power consumption to run year-round on a single solar panel.
- Industrial Communication Protocols: Built robust serial and network transmission layers using C/C++, Modbus RTU, UART, I2C, SPI, and HTTP/REST for automated edge-to-cloud data synchronization.
Prior Engineering Experience
- Embedded & Full-Stack Developer | Espiral Soluciones (Sep 2020 – Jan 2021) — Developed full-stack web platforms and embedded robotics modules for educational systems.
- Robotics Software Intern | GELECT (Jan 2020 – Jan 2022) — Engineered autonomous pathing and hardware control for UV room-disinfection robots using ROS, Python and C++.
Education
BSc in Biomedical Engineering | CUJAE (Havana, Cuba)
Languages
- Spanish: Native
- English: Fluent (C2)
- Polish: Working Proficiency (A2)