Jozsef Keresztes
Principal Production Engineer
Brentwood,CA
Summary
Principal Production Engineer with 10+ years of experience in DevOps, designing, operating, and scaling high-availability, globally distributed production systems in Big Tech environments. Expert in Linux, cloud infrastructure (AWS & GCP), Kubernetes, automation, and reliability engineering. Proven leader in driving operational excellence, improving system resilience, and supporting mission-critical platforms at massive scale. Strong command of containerization and orchestration.
Overview
19
19
years of professional experience
Work History
Principal Production Engineer
Yahoo Inc.
Brentwood, CA
02.2015 - 12.2025
- Lead production engineering efforts for Reporting and Analytics, Audience Data internal systems of users
- Own reliability, performance, and operational health across distributed Linux and cloud-based systems
- Design and automate infrastructure lifecycle using Chef, Ansible and Terraform, improving consistency and reducing operational risk
- Drive incident response, troubleshooting, and root cause analysis across OS, networking, application, and cloud layers
- Partner with engineering teams to improve system architecture, observability, and deployment strategies
- Maintain and optimize hybrid environments spanning on-prem infrastructure and AWS / GCP, ensuring stability
- Maximized productivity by 30% by developing and implementing innovative production processes for new and existing products.
- Oversaw production workflows, ensuring adherence to quality standards and operational efficiency.
- Performed root cause analysis and implemented corrective actions.
Service Engineer
Yahoo Inc.
Budapest, Hungary
10.2011 - 02.2015
- Administered and supported 1,500+ production RHEL servers in a high-traffic analytics environment
- Managed infrastructure for Yahoo Web Analytics, ensuring reliability and performance at scale
- Collaborated with globally distributed engineering teams to maintain uptime and service quality
- Improved operational tooling, monitoring coverage, and deployment reliability
- Contributed to metrics monitoring solutions, enhancing observability
- Collaborated with cross-functional teams to implement system upgrades and enhancements.
- Developed comprehensive documentation for system configurations and procedures to enhance team efficiency.
System Administrator
iSafe (Hungary)
Budapest, Hungary
08.2009 - 10.2011
- Supported home banking and internet banking platforms in regulated financial environments
- Managed Xen-based virtualization on Debian Linux hosts
- Administered VPN, proxy, and secure network services for Savings Cooperatives
- Handled monitoring, backups, and datacenter operations
- Developed a shell script to transform data between internet banking and home banking systems
- Managed system updates and patches to ensure optimal performance and security compliance.
- Automated routine tasks using scripting languages to enhance operational efficiency.
- Monitored server performance, identifying and resolving issues proactively to minimize downtime.
- Developed backup procedures, securing critical data against loss or corruption.
Progress OpenEdge Database Administrator
Takinfo Ltd. (Hungary)
Budapest, Hungary
07.2007 - 08.2009
- Administered databases for 60+ financial institutions, including the Bank of Hungarian Savings Cooperatives
- Developed shell scripts to automate database maintenance and operational tasks
- Provided Linux/Unix administration and production support
- Streamlined administrative processes to enhance operational efficiency and improve service delivery.
- Administered databases to ensure optimal performance and data integrity.
- Collaborated with development teams to design efficient database schemas and structures.
- Implemented backup and recovery strategies to ensure data integrity and availability.
- Facilitated seamless migrations and upgrades, meticulously planning and executing database changes with minimal impact on users.
Resource Manager
Takinfo Ltd. (Hungary)
Budapest, Hungary
12.2006 - 07.2007
- Designed and implemented company-wide Nagios monitoring for servers and network devices
- Integrated HP EVA storage performance metrics into monitoring systems
- Built centralized logging using syslog-ng and performed log analysis with SEC
Education
Some College (No Degree) - Information Technology Studies
Denis Gábor College
HungarySome College (No Degree) - Program Developer
Eötvös Loránd University (ELTE), Faculty of Informatics
HungaryHigh School Diploma - undefined
Váci Madách Imre Gimnázium
Skills
- Production an Site Reliability engineering
- Infrastructure automation (Terraform, Ansible, Chef)
- CI/CD pipeline management
- Incident Management & Disaster Recovery
- Cloud infrastructure management
- Performance Optimization & Capacity Planning
- Experience with monitoring tools and metrics analysis
- Experienced in Python programming
- Bash scripting
- Docker / Kubernetes orchestration skills
- AWS infrastructure management
- Experience with GCP infrastructure
- Linux system administration
- Networking Administration (Routing, Firewalls)
- Cost reduction strategies
- Critical thinking
- Teamwork and collaboration
- Problem-solving abilities
- Multitasking Abilities
Timeline
Principal Production Engineer
Yahoo Inc.
02.2015 - 12.2025
Service Engineer
Yahoo Inc.
10.2011 - 02.2015
System Administrator
iSafe (Hungary)
08.2009 - 10.2011
Progress OpenEdge Database Administrator
Takinfo Ltd. (Hungary)
07.2007 - 08.2009
Resource Manager
Takinfo Ltd. (Hungary)
12.2006 - 07.2007
High School Diploma - undefined
Váci Madách Imre Gimnázium
Some College (No Degree) - Information Technology Studies
Denis Gábor College
Some College (No Degree) - Program Developer
Eötvös Loránd University (ELTE), Faculty of Informatics