Guillermo Arribas

Senior [Software | Cloud | Reliability] Engineer

Greater Sydney Area

About

Experienced software engineer with a proven track record in designing, building and operating products from inception to production in a variety of industries (e-commerce, classifieds, SaaS). My areas of expertise are cloud infrastructure and observability.

Experience

  • Senior Site Reliability Engineer at Heidi Health
    Aug 2025 - Present · 1 yr

  • Atlassian ()
    • Senior Platform Engineer
      Jan 2024 - Aug 2025 · 1 yr 8 mos

      Design and development of Atlassian’s self-managed PostgreSQL platform, built from scratch to replace Amazon RDS and reduce cloud spend. This Kubernetes-based solution runs on EKS and uses a modified PostgreSQL Kubernetes operator for automated lifecycle management. Key achievements and responsibilities: - Designed and built the initial prototype alongside 3 engineers, securing leadership buy-in and funding for a full team - Subject matter expert (SME) on GitOps deployments, implementing ArgoCD for continuous delivery. - Led AWS infrastructure management, leveraging crossplane operator to provision cloud resources via Kubernetes-native workflows - Contributed to backend API development (Kotlin / Spring Boot) for provisioning PostgreSQL clusters - Forked and modified an existing PostgreSQL Kubernetes operator to tailor it for company needs

    • Senior Systems Engineer
      May 2022 - Dec 2023 · 1 yr 8 mos

      Atlassian's Data Management team builds and operates services that manage 4,000+ Amazon RDS instances, Aurora clusters, and over 6 million PostgreSQL databases. Key responsibilities and achievements as a senior engineer in the team: - built and maintained internal services for provisioning and managing RDS / Aurora / PostgreSQL resources - Tech stack: python, flask, tornado - acted as a subject matter expert (SME) on RDS, Aurora, and PostgreSQL, supporting Atlassian's product teams. - provided on-call support to ensure reliability and performance of critical database infrastructure.

    • Senior Cloud Engineer
      Apr 2020 - May 2022 · 2 yrs 2 mos

      Worked in the Cloud Engineering team, managing Atlassian’s cloud footprint across hundreds of AWS accounts and GCP projects. Key contributions: - developed compliance and remediation automation services for security and governance (VPC flow logs management, S3 logging, tag enforcement, cost savings) - Tech stack: python, django, SQS, PostgresSQL, memcached - managed cloud security policies using AWS Organizations' Service Control Policies (SCPs) and backup policies. - implemented real-time alerting for high-sensitivity operations using CloudTrail and AWS EventBridge - designed a scalable process for managing root credentials across AWS accounts - led the design and development of a self-service AWS account provisioning service - Tech stack: SAM, API Gateway, Lambda, Step Functions, DynamoDB, python

  • EXOS ()
    • DevOps Engineer
      Jan 2017 - Dec 2018 · 2 yrs

      As a remote DevOps engineer, I was responsible for designing, automating, and scaling cloud infrastructure and CI/CD pipelines to support EXOS' engineering teams. Key achievements and responsibilities: - Designed and implemented the development environment, initially used Packer and custom Vagrant Ruby plugins, later migrated to Docker Compose - Developed CI/CD tooling with Jenkins & Groovy pipelines, improving build and deployment automation - Led the migration of micro-services to containers using Docker & Kubernetes, increasing scalability and maintainability. - Built an on-demand test automation infrastructure for QA using AWS & Docker, reducing testing bottlenecks. - Provided troubleshooting and support across development, QA, and production environments.

    • Backend Team Lead
      Jul 2014 - Dec 2016 · 2 yrs 6 mos

      Led a distributed backend team in designing and developing a SaaS product in the wellness vertical. Key Contributions: - Designed and developed backend services using Python, Redis, MySQL, AWS. - Led project teams, coordinating efforts across multiple engineers. - Mentored junior developers, improving team skill levels and onboarding processes. - Reviewed functional specifications & provided estimates, ensuring feasibility and alignment with business goals.

  • Founder at Certalia
    Sep 2011 - Jun 2014 · 2 yrs 10 mos

    Founded Certalia, an edtech startup providing online test preparation for English proficiency exams (IELTS, TOEIC, FCE). Key achievements: - Designed and built the platform using Python, PostgreSQL, and Heroku, delivering an interactive learning experience. - Secured $USD 40,000 in equity-free seed capital from Start-Up Chile, funding product development and growth - Managed a team of contractors for content creation and administrative operations, ensuring high-quality educational materials

  • Partner at RESONATE MP4
    Jan 2010 - Nov 2010 · 11 mos

    Design and implementation of a video transcoding and multimedia processing platform deployed in a cloud computing infrastructure (Java, C++, AWS).