Resume
Juan Diego Sierra Fernández
Platform Engineering Lead | SRE / DevOps | Cloud Architect | AI Enablement
Summary
Infrastructure, platform, and site reliability engineer with 10+ years of experience building and operating scalable systems, and a track record of leading engineering teams.
I have put AI tooling into production to improve how teams build and ship software, worked at early-stage startups where I standardized processes from scratch, and at large corporate environments with strict procedures and compliance requirements.
Having worked as both a software developer and an infrastructure engineer, I have a thorough understanding of the entire software delivery lifecycle.
Interested in leadership positions such as Staff Engineer, Principal Engineer, or Head of Platform.
I encourage you to read my manifesto to see if my engineering mindset aligns with your company's values.
Open Source
Contributions
claude-code-templates +23K ★
Claude Code community templates and reference configurations.
helm-unittest +1.2K ★
BDD-style unit test framework for Kubernetes Helm charts.
opentelemetry-helm-charts +500 ★
Official OpenTelemetry Helm charts for Kubernetes.
openfga/helm-charts +40 ★
Official Helm charts for OpenFGA authorization service.
My Projects
contributor-report +60 ★
GitHub Action that evaluates contributor quality and helps teams catch spammy AI-generated PRs with objective signals.
enterprise-agent-plugins
Extensible plugin system for enterprise AI agent pipelines and workflows.
enterprise-agent-operator
Kubernetes operator for deploying and managing enterprise AI agents at scale.
observability-cli
CLI tool for querying and analyzing observability data across Grafana, Loki, and Mimir.
Experience
Platform Engineering Lead
Maisa AI
- Lead a team of 6 infrastructure engineers and report directly to the CTO.
- Drive AI adoption across the SDLC, improving engineering speed, developer productivity, and delivery quality.
- Build production-grade AI workflows, agents, skills, and plugins for internal engineering use cases.
- Operate the platform on AWS, supporting both Maisa's own SaaS product and customer-deployed Helm chart installations.
- Drive FinOps and cloud cost optimization: keeping spend visible, cutting waste, and making sure infrastructure costs actually make sense.
- Administer Jira across the organization, including project configuration, workflows, automations, and board management.
- Implement security and compliance standards including SOC 2 and ISO 27001.
- Collaborate with developers to design and operate the full CI/CD lifecycle with GitHub Actions.
- Release and maintain a public Helm chart, manage production Kubernetes and OpenShift workloads with Karpenter, and operate ArgoCD for continuous delivery.
- Provision infrastructure with Terraform, Terragrunt, Pulumi, and Crossplane using a GitOps approach.
- Build and operate monitoring and observability with Grafana, Mimir, Loki, Tempo, and OpenTelemetry.
Site Reliability Engineer
The Workshop
- Standardized CI/CD processes across 7 product verticals, improving consistency and deployment quality.
- Managed and maintained 50+ Kubernetes clusters supporting large-scale production workloads.
- Created and maintained Docker images, Helm charts, GitLab pipelines, and Ansible playbooks for scalable platform operations.
Site Reliability Engineer
Mindcurv
- Improved the cloud infrastructure powering auxmoney.com, increasing reliability, scalability, and performance.
- Managed 30+ AWS accounts, ensuring governance, security, and automation standards.
- Improved and maintained Ansible playbooks used to provision and manage server infrastructure.
Platform Engineering Lead
Bdeo
- Responsible for all cloud infrastructure and CI/CD pipelines, reporting directly to the CTO.
- Designed and maintained cloud-native and serverless architectures on AWS.
- Managed the entire company AWS estate, including CloudFormation, API Gateway, Lambda, CloudFront, Route 53, EC2, DynamoDB, RDS, and Fargate.
- Drove DevOps culture adoption across teams, improving CI/CD workflows with GitLab pipelines and internal tooling.
- Designed and developed horizontal platform services to accelerate product development.
- Worked closely with support and engineering teams to diagnose incidents and unblock delivery.
Senior Software Developer
Bdeo
- Worked as a senior developer in the product team, performing reviews, designing services, and improving legacy code.
- Refactored AWS Lambda functions to TypeScript, improving code quality, type safety, and maintainability.
- Created best practice guides and coding standards to align developers and raise the quality bar across teams.
- Designed, deployed, and maintained AWS infrastructure supporting core product services.
Senior Blockchain Developer
Airbus Defence & Space
- Led international blockchain projects with teams across Germany, Italy, Spain, and France.
- Designed and implemented a custom blockchain from scratch using Python and LevelDB.
- Designed blockchain solutions using private networks with Hyperledger Fabric and public networks with Ethereum.
Embedded Software Developer (Intern)
Altair
- Developed a customized fork of Node-RED using Node.js.
- Built software for IoT devices in C/C++.
- Worked with Bluetooth, RabbitMQ, ThingWorx, Sigfox, LoRa, RFID, and WiFi protocols and technologies.