Torsten Bøgh Köster

I support customers facing challenges in their search or operations environment (or both). I build Kubernetes clusters with infrastructure as code and observability in mind both in the cloud and on-premise.

Key customer projects:

• Built a Google Gemini based product discovery chatbot for a large ecommerce client. I focused on the observability aspects using Langfuse to monitor and track LLM interactions.
• Prototyped a search engine and ui for a agricultural publishing house using GenAI techniques. It showcased various approaches including an LLM based clustering of search results and a RAG based question answering system.
• Reduced cloud costs by 50% for an e-commerce search engine using an holisitic approach. This included an overhaul of the system architecture and also implemeting custom Solr plugins to reduce resource consumption for long running queries.
• Bridging the gap between devs and AWS cloud infrastructure in a e-commerce search project. Introduced Prometheus based observability and led a team overhauling the overall system architecture.
• Introduced sharding into a e-commerce Solr search platform. Refactored all internal components and made algorithms sharding ready. Also updated the installation from the Solr 7.x release train to Solr 8.11 and onwards to Solr 9.9.
• Acting as a trusted advisor for a junior search team taking over a aging Solr search infrastructure. Guided them through the overhaul of the autocomplete to get to know their search infrastructure.
• Introduction of Ansible and infrastructure as code in a large on-premise infrastructure. Automated and scalable setup of Kubernetes clusters using Ansible and kubeadm. Log management and monitoring for two data centers using Graylog and Prometheus.
• Seeding the idea of infrastructure as code for both on-premise and cloud infrastructure. Setup of SaltStack for the on-premise environment and Terraform for AWS infrastructure. Automated setup of Kubernetes (EKS) clusters including VPCs and ingress handling.
• Migration from on-premise infrastructure to Google GCP including site-2-site VPN, dialin VPN and scalable Kubernetes clusters.

Technologies used:

• Solr
• Ansible
• Kubernetes
• Terraform
• Logstash, Filebeat & Graylog
• Prometheus & Grafana
• Amazon AWS
• Digital Ocean
• Google GCP
• Traefik
• Keycloak
• Packer

Started midmind.de to support my wife (a midwive) with an AI powered knowledge base using a RAG approiach on proofed literature and guidelines. The platform is currently in private beta and is my testing ground for RAG and LLM observability.

Technologies used:

• Spring AI
• PGVector
• OpenAI
• Langfuse

Founded ping7.io together with Henrik to offer managed exporters for Prometheus. In a first phase we offered global installations of the Blackbox Exporter to supply website uptime metrics to you Prometheus instance. We utilised multiple cloud providers for a efficient but globally distributed setup.

Technologies used:

• Prometheus Blackbox Exporter
• Spring Boot
• Spring Cloud Gateway
• Hetzner Cloud

Accountable for developing and operating the shopping24 product search platform. Together with the engineering team I maintain the api and search backend based on Apache Solr, the product backend systems (Java) and the portal frontends (PHP). I code on a regular basis in both operations and search and assist the teams in system- and software architecture challenges.

Key projects:

• Insourcing of server operations: Development of a centralized configuration management using Ansible. Setup of a hybrid cloud hosting using bare metal, VMWare and KVM hypervisors as well as Amazon AWS. Recently pushing the transition into containerization using Docker, Kubernetes and Ceph as distributed storage.
• Design and implementation of a inner source e-commerce search solution for the Otto Group based on Apache Solr. Onboarding and consulting of several Otto Group companies like otto.de and Limango.
• As a in-house consultant I joined the implementation of the e-commerce search at otto.de and Limango. Implemented technical and relevance search monitoring, extended the CI/CD pipeline to do blue/green deployments.
• Building and eventually spun off a SaaS to manage Google and Bing ads at large scale. Wrote an entity extraction as a Apache Solr plugin in order to categorize ad terms. The software is used by multiple tenants inside the Otto Group.

Technologies used:

• Apache Solr
• Ranklib
• Kubernetes
• Spring Boot
• Java 11
• Docker
• Kubernetes
• Logstash
• Filebeat
• Graylog
• Nginx
• HAProxy
• Traefik
• Varnish
• Prometheus
• Grafana
• Graphite
• Elasticsearch
• Ansible
• KVM
• Ceph

Responsible for restructuring and refactoring the Java API and product management backend.

Key projects:

• Recruitment and training of the Java development team. Insourcing of Java development and application support for the existing Java applications.
• Review of the existing system and software architecture. Refactoring towards an elastic and service oriented architecture. Moved traffic and storage intensive data to Amazon AWS.
• Introduced Scrum as development process. Established a modern Java development infrastructure for Continuous Integration und Continuous Delivery.
• Conceptual design and implementation of a modular REST api for delivering affiliate product data based on Apache Solr.
• Centralizing logging, server, application and business metrics for real time analysis.

Technologies used:

• Apache Maven
• Amazon EC2
• Amazon S3
• Amazon CloudFront
• MongoDb
• Apache Solr
• Apache Hadoop
• Apache Mahout
• Zookeeper
• Jenkins
• Sonar
• Artifactory
• Github
• Redmine
• New Relic
• Graylog2
• Logstash
• StatsD
• Graphite
• Grafana
• Collectd

Developer, architect and in-house consultant for Java based projects focusing on integrating legacy systems into modern web UIs. Technical lead for internet and intranet web applications. Maintainer of the Java development and continuous integration infrastructure.

Key projects:

• Prepared and led advanced in-house Java, Spring Framework, Maven & Eclipse trainings
• Technical team lead for web applications serving customers and insurance brokers.
• Switched the complete Java codebase from building with Ant to Maven, maintained build server for continuous integration and Maven infrastructure components
• Created an Eclipse RCP based distribution platform for remote offline viewing of data warehouse data cubes

Technologies used:

• Java
• Eclipse RCP
• Spring
• Hibernate
• Spring Security
• Central Authentication Service (CAS)
• IBM DB2
• IBM Content Manager
• IBM MQSeries
• Websphere Application Server
• Tomcat
• Lucene
• Hudson
• Sonar
• Artifactory

Acquired and implemented Java and PHP development jobs. Gained knowledge of Linux server administration in high traffic environments as systems administrator for the largest soccer community in Germany.

Technologies used:

• PHP
• MySQL
• Wordpress
• Lighttpd
• Debian Linux

Developed custom tailored applications for german high traffic websites in PHP and Perl.

Technologies used:

• PHP
• Perl
• LAMP stack