Carlos González Sacristán
Senior engineer. Backend, platforms and infrastructure.
Senior software engineer with 10+ years of experience designing, building and operating complex systems end to end. Strong background in backend development, platform engineering, DevOps and modern data architectures. I specialise in taking ownership of technically demanding systems, improving delivery speed, reliability and operational clarity. Comfortable working remotely, autonomously, and directly with technical and non-technical stakeholders.
Experience
Building a domain-oriented data platform inside a legacy multi-account AWS environment (ProServe-built, three years underutilized) with OpenTofu, Terragrunt, Databricks, Snowflake, and Confluent Cloud. Designed minimum-privilege network paths across a firewall-inspected environment to integrate new workloads without disrupting existing isolation. Goal: replace ~1,500 fragmented ETL jobs with structured, team-owned pipelines.
SRE on a 4-person team supporting internal CI/CD and application lifecycle management platforms used across the organisation. Maintained and evolved internal APIs and services supporting build, deployment and runtime operations. Took ownership of Python and Go services, ensuring reliability, maintainability and operational consistency under significant inherited technical debt in a highly regulated enterprise environment.
Designed and shipped an internal deployment platform used by 17 projects across 3 environments: 3,000+ releases in six months; deployment time under 5 minutes. Developed custom GitHub Actions and containerised workflows; replaced the legacy Ansible pipeline. Managed and maintained multiple Kubernetes clusters for clients, with health checks and automatic rollback. Technical mentor and bridge between product, platform and operations teams.
Full-stack developer at a 30-person software agency (~15 developers). End-to-end development of data-intensive client platforms: a dynamic form framework driven from the backend and integrated with Vuelidate, secure document-handling and user-onboarding flows, and direct collaboration with client technical teams. Became one of two go-to people for Python, Django, and frontend questions alongside the CTO, progressively accumulating infrastructure and deployment responsibility, leading to a formal transition into an SRE role.
Co-designed and built a data product to aggregate and recommend cultural events by location and interests. Led the backend architecture: APIs with FastAPI, processing with Kafka, search with Elasticsearch. Built ingestion and normalisation pipelines from multiple heterogeneous sources. Fully containerised stack with Docker and Docker Compose.
Automated the full testing and validation workflow for Caravel, an IBM iSeries emulator and legacy software converter. Built Python and shell tools to run reproducible conversion tests from plain-text definitions, replacing hours of manual validation. Contributed to the framework core and refactored decade-old code. Introduced git, Maven and automated builds to modernise team practices.
Software engineer consultant deployed to a large Spanish banking client. Analysed and improved poorly-performing Java services, resolving a critical thread-pool and concurrency issue that had blocked the team for days. Redesigning the main processing loop brought system throughput up dramatically and made full use of available compute for the first time. Contributed to a transaction registry pipeline integrating modern Java services with legacy mainframe systems.