Verifiable Engineering: Architecture, Metrics & Production Code
Zero vanity metrics. Every case study breaks down real operational problems, systems architecture, code-verified data points, and technical lessons learned in production.
Pablo Fesa · Software Architect & Tech Lead
10+ years of software engineering taking full ownership of what the industry demands from a senior backend engineer: robust API design with idempotent contracts, relational and NoSQL data modeling with index profiling, decoupled asynchronous processing (RabbitMQ, Redis), in-memory acceleration (OPcache, Memcached), proactive observability (structured logging, APM, and metrics), security by design (OWASP, SSDLC guidelines, Zero Trust), and automated delivery through continuous test suites and CI/CD pipelines across cloud and bare-metal environments.
Enterprise SAT & Warranty Integration Platform in Benelux
Diario de Subastas: Legaltech Marketplace & Auto-Bidding Engine
High-Performance Rust LLM Gateway
PeritIA: LangGraph Vehicle Appraisal Agent
Automated Linux Server Provisioning & Hardening
MyGarage: Mobile & Self-Hosted Cloud Platform for Vehicle Management
Automated Customs Declarations (DUA) Processing Engine
Accounting & Jackpot Distribution Dashboard for Gaming Venues
Enterprise VoIP Telephony & Digital Relay for Central Government (AGE)
QSnaps: The Zero-Install Digital Disposable Camera
Voice AI English Language Tutor
La Quinta Almena Restaurant: Jamstack Web Platform & Headless CMS
Engineering Notes & Systems Design
Technical trade-offs, performance benchmarks, and real production lessons straight from the codebase.
Laya on CPU, No GPU: What I Measured on Three Machines Before Putting It in Production
38ms was with a GPU. On CPU, 94 to 848ms depending on the machine. Real benchmarks, the thread trap, ONNX vs PyTorch, and how the deployment ended up on a VPS.
Hexagonal Architecture and DDD in Laravel: Decoupling Domain from Eloquent with DTOs and Repositories
How to architect complex enterprise applications in Laravel without letting Eloquent pollute business rules: Ports and Adapters, immutable PHP 8.2 Value Objects, and strict layer boundaries.
PHP at Planetary Scale: Slack, Meta, Strict Typing with PHPStan, and Fibers Concurrency (Part 4)
Why tech giants like Slack, Wikipedia, and Meta continue investing in PHP: the operational economics of stateless workloads in Kubernetes, maximum static analysis, and cooperative concurrency with Fibers.