Liam O'Brien
DevOps Engineer
Profile
Results-driven DevOps Engineer with 4 years of experience specialising in cloud infrastructure automation, container orchestration, and CI/CD pipeline optimisation. Proven track record of managing AWS environments serving 5M+ daily users while achieving 99.97% uptime SLA. Expert in Infrastructure as Code using Terraform, with deep knowledge of Kubernetes, Docker containerisation, and monitoring solutions across high-traffic production environments.
Experience
Lead DevOps engineer responsible for managing critical AWS infrastructure serving over 5 million daily users across multiple betting platforms and gaming products.
- Designed and implemented robust CI/CD pipelines using GitHub Actions, reducing deployment time from 45 minutes to 8 minutes and increasing deployment frequency by 300%
- Achieved 99.97% uptime SLA through comprehensive monitoring with Datadog and automated failover mechanisms using PagerDuty, preventing £2.3M in potential revenue loss
- Managed multi-region AWS infrastructure using Terraform and CloudFormation, optimising costs by 25% through right-sizing and reserved instance planning
- Implemented blue-green deployment strategies across 30+ microservices, eliminating downtime during releases and reducing rollback incidents by 85%
- Led security hardening initiatives including AWS IAM policies, VPC configurations, and automated vulnerability scanning, achieving SOC 2 Type II compliance
- Mentored 2 junior engineers in DevOps best practices, Infrastructure as Code principles, and cloud architecture design patterns
Supported DevOps operations for the UK's largest automotive marketplace platform, handling infrastructure automation and container orchestration for high-availability services.
- Successfully containerised 15+ legacy microservices using Docker, reducing deployment complexity and improving scalability by 200%
- Deployed and managed Kubernetes clusters on AWS EKS, handling 500+ pods across development, staging, and production environments
- Automated infrastructure provisioning using Terraform, reducing manual setup time from 3 days to 2 hours and eliminating configuration drift
- Implemented comprehensive ELK stack (Elasticsearch, Logstash, Kibana) for log aggregation, processing 50GB+ daily logs and reducing MTTR by 60%
- Built custom Grafana dashboards and alerting systems, providing real-time visibility into application performance and infrastructure health
- Collaborated with development teams to implement GitOps workflows, improving code quality through automated testing and deployment gates
Gained hands-on experience in enterprise cloud infrastructure management and automation within the financial software division.
- Assisted in migrating 5 legacy applications to AWS cloud infrastructure, reducing operational costs by 15%
- Contributed to automation scripts in Python and Bash, streamlining routine maintenance tasks and reducing manual effort by 40%
- Participated in incident response procedures, documenting findings and contributing to post-incident reviews
- Supported monitoring system configuration using CloudWatch and helped implement basic alerting mechanisms
- Shadowed senior engineers in infrastructure planning meetings and contributed to technical documentation updates
Skills
- AWS (EC2, EKS, RDS, S3, Lambda)
- Terraform
- Docker
- Kubernetes
- CI/CD Pipelines
- GitHub Actions
- Linux Administration
- Python
- Datadog
- Grafana
- Jenkins
- Ansible
- CloudFormation
- ELK Stack
- Prometheus
- PagerDuty
- Git
- Bash Scripting
- Monitoring & Alerting
- Infrastructure as Code
Education
Certifications
- AWS Certified Solutions Architect - Associate
- Certified Kubernetes Administrator (CKA)
- HashiCorp Certified: Terraform Associate
- AWS Certified DevOps Engineer - Professional (In Progress)