Omer Sen
Verified Expert in Engineering
DevOps Engineer and Software Developer
London, United Kingdom
Toptal member since January 22, 2020
Omer is a highly accomplished DevOps, DevSecOps, and MLOps developer who has been incorporating experience in these fields since 1999. He started as a Unix, Linux, and Windows administrator and then transitioned to security before his current consultancy role. He has expertise in Kubernetes, CI/CD, Ansible, Packer, and IaC. Omer's favorite cloud providers are AWS, Azure, and Google Cloud, which he uses on various projects for startups and different-size companies in multiple industries.
Portfolio
Experience
- Linux - 20 years
- DevOps - 20 years
- Terraform - 10 years
- DevSecOps - 10 years
- Amazon Web Services (AWS) - 10 years
- Kubernetes - 9 years
- Azure - 6 years
- Google Cloud Platform (GCP) - 6 years
Preferred Environment
Ansible, Docker, Kubernetes, Linux, Amazon Web Services (AWS), Azure, GitHub, Terraform, Machine Learning Operations (MLOps), DevSecOps
The most amazing...
...system I've developed and maintained using open-source components is a telecom tool handling five million subscribers.
Work Experience
Senior DevOps
Freelance Clients
- Developed CI/CD pipelines using Azure DevOps, Argo CD, Jenkins, GitHub workflow, and GitLab CI/CD for the back end, front end, and mobile applications.
- Installed Azure AKS, AWS EKS, Google GKE clusters, and Helm charts via Terraform and created pipelines for Docker image and automation for dev, staging, and prod environments.
- Created Azure VM and AWS AMI images via Packer and Ansible.
- Created two MLOps environments from scratch for pharmaceutical companies. Installed, designed, and maintained them on Azure and AWS using SageMaker and Kubeflow. Handled the inferencing part and created a GitOps-compliant MLOps environment.
- Designed and implemented OCI solutions for three enterprise-level clients. Migrated AWS resources to OCI. Created and maintained Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE). Designed pipelines for OCI and OKE.
- Installed Elastic (ELK and Elastic Cloud) and Splunk for the customer's needs. Integrated with SOAR or with vulnerability scanning tools such as Rapid7.
- Installed and provisioned 5120 B200 GPU systems with HP Servers. Automated installation with Foreman.
- Installed on-prem and cloud Kubernetes (using Rancher/RKE2) cluster with GPU using GPU Operator on A100 and B100/200 GPU.
- Automated single-node/server GPU-based K8S/Kubernetes environments for developers using K3S.
- Baked GPU-based Qcow2 nodes using Packer and Ansible roles.
Senior DevOps | DevSecOps Consultant
Serra Consultancy Services Ltd
- Created and maintained a big data infrastructure that handles over ten billion records daily while running on AWS. The tech stack includes AWS S3, IAM, EMR, EKS, Lambda, and CloudTrail; Amazon VPC, EC2, CloudWatch; Apache Airflow; and JupyterHub.
- Migrated a monolithic application to AWS EKS, GKE, and bare-bone Kubernetes. I also designed a pipeline with security and flexibility in mind and created a Jenkins pipeline for Docker image and AMI creation using Packer and Ansible.
- Led the firewall migration from Check Point to Palo Alto PA-5220 using the expedition tool.
- Migrated two startups from on-prem to AWS and one company from Google Cloud to Azure. Also worked heavily on Cloud Native projects.
- Developed and upgraded several Terraform modules for AWS, Azure, and VMware vSphere; also wrote pipelines using Jenkins, GitLab CI/CD, Argo CD, Azure DevOps, and GitHub Actions.
- Installed a custom-built machine learning operations (MLOps) pipeline using Seldon, Argo CD, Argo Workflows, Azure DevOps, and Kubeflow.
- Conducted the migration of clients from Google Cloud Platform (GCP) to Azure and from on-premises systems to AWS, Azure, and GCP.
- Installed and designed Azure and Azure AKS cloud environment with Azure DevOps automation. Used packer to build Azure VMs with Ansible. Automated with Terraform IaC tool. Integrated Azure with Github. Migrated the client from GoogleCloud to Azure.
- Implemented and used Jenkins, GitHub, GitLab, Argo CD, and Azure DevOps as CI/CD tools and integrated security, functional, and UA tests to CI/CD pipelines.
- Created an on-premises Kubernetes cluster using VMware, KVM, GPU, and Graphcore.
Linux Consultant
SUSE
- Drove revenue while working with sales colleagues and owned the technical sales cycle.
- Worked with partners, consultants, support, and the education team on new opportunities within our customers and prospects.
- Initiated and/or assisted in proposal creation and proposed, prepared, and delivered proofs of concept.
- Delivered valuable market and customer feedback to our product management organization.
- Provided sales, enablement, and training assistance in partner opportunities.
- Contributed to marketing events including trade shows, seminars and conferences as a subject matter expert.
Senior Consultant
Serra Bilisim
- Consulted on Linux and SecOps as well as on Oracle (Oracle Linux), Red Hat, and Solaris 10 operating systems.
- Worked as a half-time instructor for Red Hat (RHEL7), Solaris 10, Snort, and SIEM products.
- Ensured the cybersecurity compliance for different companies for PCI, SOX, ISO27001 compliance using different products such as Rapid7, Tenable (Nessus), Tripwire, and Centrify.
- Worked with customers to gain value and acted as a trusted advisor on different projects.
Chief Architect
Endersys
- Acted as a system administrator for six years at Endersys—installing and managing Linux (RHEL, Red Hat, Centos, SLES, OEL, and Oracle) and Solaris (SPARC) operating system.
- Oversaw and was technically responsible for Endersys' other security products including Rapid7, Tenable, Tripwire, Centrify, and FireEye; and also created the PoCs and provided support.
- Learned the technical ins and out of different products to enable and manage technical teams to adapt and learn products fast.
- Managed and designed million user web servers (Apache), FreeRADIUS, clusters, mail servers (Gmail, Postfix), middleware (JBoss, Tomcat) also used monitoring solutions such as Nagios, Cacti, and Solarwinds.
Senior TAC Engineer
Alcatel
- Provided support for Alcatel’s DSLAM (DSL Access Multiplexer) software that was running on Solaris 10.
- Updated customers' (telcos around the EMEA, Africa, and Asia) software on-site that handled more than 1 million DSL subscribers.
- Oversaw and was responsible for their Solaris Lab containing different versions of Solaris and SPARC hardware.
- Designed the JumpStart environment and worked as the oncall support engineer for their DSLAM management software on Solaris 10.
System and Security Researcher
Tubitak
- Managed the webserver (LAMP), DNS server (DJBDNS), firewall (PF, IPF), backup solutions (Bacula) and maintained various servers based on RHEL, OpenBSD, FreeBSD, and Suse Enterprise Linux. Also migrated OpenBSD firewalls and designed new networks on need.
- Consulted with various software teams on designing solutions (firewall, VPN, and IPSEC) including making from scratch a FreeBSD-based firewall process appliance and designed the software release build.
- Wrote OS auditing guidelines for Tru64 Uni, Linux, Solaris, IBM AIX, and HP-UX.
- Audited various customers including military and private companies.
- Built various security checking tools using shell scripts.
- Acted as an instructor for Linux/Unix OS security for different customers.
- Provided training for open-source security products.
- Installed Snort on Linux for government/finance organizations.
Experience
Cybersecurity Training and Product Demo Portal
Education
Bachelor of Science Degree in Electronical and Communication Engineering
Yildiz Technical University - Istanbul, Turkey
Certifications
Rapid7 InsightIDR Certified Specialist
Rapid7
Rapid7 AppSpider Certified Specialist
Rapid7
Rapid7 InsightVM, Nexpose Certified Administrator
Rapid7
SLES System Administrator
SUSE
Tripwire Enterprise Product Technical Certificate
Tripwire
Citrix Certified Professional — Networking (CCP-N)
Citrix
Red Hat Certified System Administrator (RHCSA)
Red Hat
Red Hat Certified Engineer (RHCE)
Red Hat
Skills
Libraries/APIs
Node.js, Back-end APIs, vLLM, Terragrunt, REST APIs, Google Apps, OpenLDAP
Tools
Jenkins, Ansible, Nexpose, Google Kubernetes Engine (GKE), Terraform, GitHub, GitLab, pfSense, Prisma, Grafana, Helm, Amazon EKS, Istio, Amazon Virtual Private Cloud (VPC), ELK (Elastic Stack), HashiCorp, Git, Subversion (SVN), Cron, Nagios, VMware, Kibana, Vault, SonarQube, Azure Kubernetes Service (AKS), Ansible Tower, Apache, Splunk, Squid Proxy Server, NGINX, Chef, Puppet, SolarWinds, Amazon CloudWatch, Logstash, VMware vSphere, Elastic, Amazon Elastic Container Service (ECS), Keycloak, AWS CloudFormation, MongoDB Atlas, Splunk SOAR, OpenVPN, Dynatrace, PgBouncer, Amazon SageMaker, Azure Key Vault, Bitbucket, Artifactory, AWS Key Management Service (KMS), AWS IAM, Google Workspace, Azure DevOps Services, Azure Monitor, Jira, Zabbix, Docker Swarm, Confluence, Observability Tools, HashiCorp Vault, VPN, Azure Application Gateway, Docker Compose, Google Compute Engine (GCE), RabbitMQ, Kustomize, Hyper-V, Amazon Elastic MapReduce (EMR), Packer, Apache Airflow, Red Hat Satellite, Twistlock, GitLab CI/CD, Microsoft Teams, Microsoft AI, ChatGPT, Cloud66, Apache Tomcat, Digital Subscriber Line Access Multiplexer (DSLAM), Kafka Streams, Red Hat Enterprise Virtualization (RHEV), CircleCI
Languages
Bash, Bash Script, SQL, Python, SAML, JavaScript, YAML, PHP, Snowflake, Ruby, Domain-specific Languages (DSLs), Java
Frameworks
Django, .NET, Apache Spark, Flux, SPF, Crossplane, Next.js, Windows PowerShell, Hadoop
Paradigms
DevOps, DevSecOps, Deep Packet Inspection (DPI), Continuous Integration (CI), Automation, Enterprise Application Architecture, Azure DevOps, Penetration Testing, Microservices Architecture, ETL, Serverless Architecture, Hosting, Software-defined Networking (SDN), Role-based Access Control (RBAC), Agile Project Management, HIPAA Compliance, Microservices, Load Testing, Continuous Delivery (CD)
Platforms
Linux, Unix, Kubeflow, Kubernetes, Docker, Red Hat Linux, Azure, Amazon Web Services (AWS), OpenStack, Windows, Google Cloud Platform (GCP), Windows Server, Ubuntu, Apache Kafka, OpenShift, Amazon EC2, DigitalOcean, Mobile, JBoss, NVIDIA CUDA, CentOS, Debian, AWS Lambda, Oracle, Oracle Cloud Infrastructure (OCI), LAMP, Azure Marketplace, Debian Linux, AWS Cloud Computing Services, Red Hat OpenShift, Rancher, Vanta, Rackspace Cloud, Solaris, OpenBSD, FreeBSD, Seldon, Polyaxon, RouterOS
Industry Expertise
Cybersecurity, Telecommunications, Healthcare
Storage
Azure Active Directory, MySQL, Elasticsearch, MongoDB, Azure Blobs, Storage Area Networks (SAN), PostgreSQL, Redis, Databases, Ceph, Azure Cloud Services, Memcached, Google Cloud, Database Architecture, NoSQL, JSON, NetApp, Data Centers, MariaDB, Nextcloud, On-premise, Amazon S3 (AWS S3), Google Cloud SQL, OVH, Auto-scaling Cloud Infrastructure, Google Bucket, WP Engine, Datadog, SQL Server Integration Services (SSIS), SUSE, Microsoft SQL Server
Other
Machine Learning Operations (MLOps), Argo CD, Monitoring, Hypervisors, Firewalls, Palo Alto Networks, CI/CD Pipelines, Site Reliability Engineering (SRE), Shell Scripting, DevOps Engineer, Prometheus, System Administration, Load Balancers, Enterprise Architecture, Infrastructure as Code (IaC), DNS Debugging, Service Meshes, SFTP, Architecture, AWS Cloud Architecture, Networks, Networking, Security, Cloud Security, Containerization, Virtualization, Network Engineering, NVIDIA A100 Tensor Core GPU, Mellanox Technologies, Back-end, Cloud Services, HAProxy, Big Data Architecture, AWS Certified Solution Architect, Cloud Architecture, Big Data, Microsoft Azure, Azure Virtual Machines, API Gateways, System Architecture, Linux Administration, User Permissions, Clustering, Access Control, Distributed Systems, Amazon RDS, Cloudflare, DNS, System Migration, Configuration Management, DNS Configuration, Network Security, Proxy Servers, Argo Workflow, Servers, Web Servers, Vulnerability Assessment, Cloud, APIs, Agile DevOps, Cloud Engineering, Identity & Access Management (IAM), Splunk Enterprise Security, Zero Trust, SAML-auth, IP Routing, Border Gateway Protocol (BGP), Fortinet Firewall Configuration, TCP/IP, AWS DevOps, Kubernetes Operations (kOps), Scripting, Cloud Infrastructure, VMware ESXi, Network Automation, IT Security, Security Policies & Procedures, Deployment, SSL Certificates, SSL Configurations, Virtual Machines, Network Architecture, GPU Computing, Web Application Firewall (WAF), Technical Documentation, Dashboard Development, Infrastructure, Integration, SecOps, Data Center Infrastructure, Veeam, Backup & Recovery, GitOps, Performance Analysis, ECS, GitHub Actions, Containers, Machine Learning, Data Versioning, Infrastructure as a Service (IaaS), Orchestration, Scalability, Slurm Workload Manager, Windows System Administration, Transport Layer Security (TLS), Mail Servers, Amazon EventBridge, Email Delivery, Reputation Management, DMARC, DomainKeys Identified Mail (DKIM), Software-defined Data Centers (SDDC), Scripting Languages, NFS, High Availability Disaster Recovery (HADR), Compliance, Azure Cloud Security, PKI, DataOps, Systems Engineering, Pulumi, Email, Business Services, Migration, Cloud Migration, General Data Protection Regulation (GDPR), ISO 27001, IT Infrastructure, IT Administration, Zoho Mail, Email Migration, Virtual Desktop Infrastructure (VDI), SSH, Redmail, Unix/Linux Virtualization, Azure CLI, Application Monitoring, Artificial Intelligence (AI), IT Networking, Data Migration, Email Systems, Reliability Engineering, HashiCorp Cloud, Reliability, Disaster Recovery Consulting, Uptime Monitoring, eCommerce, DNS Servers, VLANs, Solution Architecture, Azure Resource Manager (ARM), Bare-metal Environment, OpenTelemetry, Terraform Cloud, Virtual Private Cloud (VPC), Azure Administrator, Azure Repos, Linux System Administration, Infrastructure Testing, Rancher Kubernetes Engine (RKE), Longhorn, Open-source LLMs, AI Agents, Open-source Intelligence (OSINT), AWS GovCloud, GCP DevOps, Documentation, IT Infrastructure Management (ITIM), NAT, Podman, AI Architecture, Checkpoints, Telemetry, AWS Transit Gateway, InfiniBand, Office 365, IIS, Cisco Routers, Apache Cassandra, SS7, 5G, Data Visualization, Kerberos, Cisco, Okta, Large Language Models (LLMs), Training, Open Source, Qmail, MLflow, Jaeger, Training & Training Content Development, Electronics, Communication, GSM, GitHub Workflows, 4G, DHCP, Splunk ITSI, Graphics Processing Unit (GPU)
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