About

Work Experience

• Engineering Team Lead, Sammelkartenmarkt GmbH

  Feb, 2025 - Present

• Staff Engineer, Sammelkartenmarkt GmbH

  Mar, 2024 - Feb, 202511 months

  System design, integrations, architecture decisions, alignment with business goals.

  • Pioneered the adoption of Go (Golang)

  • Piloted a project adopting a modern microservices stack: ARMv8, Go (Golang) 1.23, Echo Framework, DDD, Kubernetes (K8s) on AWS EKS, Kind, Terraform, Helm, Flux CD and OpenAPI 3.1

  • Drove the successful launch of the company's first Go (Golang) microservice from conception to deployment, handling planning, architectural design, documentation, and hands-on implementation

  • Integrated New Relic's for APM and Metrics, Events, Logs, Traces, Distributed Tracing improving Observability

  • Improved code quality with new GitLab CI for static analysis and linting, to maintain high software standards

  • Designed and implemented a new SDK, packaged and deployed via own GitLab repository, to decouple search feature component

  • Orchestrated organizational shift from monolithic to domain-focused team structure

  • Creation and leadership of engineering squad: self-organizing team focused on delivering features with end-to-end ownership

• Senior Software Engineer, MessageBird B.V.

  Jun, 2022 - Dec, 20231 year 7 months

  Building scalable foundation services: Golang, K8s, AWS, GCP, PHP for accounts, accounting, billing, payments.

  • REST APIs, OpenAPI v3, Google GRPC & protobuf APIs both in PHP8 and Golang 1.20

  • Developed microservices in platform system, product services, api-first, domain-driven design

  • Developed Customer WEB/UI self-service portal

  • Designed and implemented SLO/SLI metrics and alerting with Grafana & Prometheus for K8s apps

  • Optimized Billing cluster runtime >5000 RPS ledger OLTP workers: 60% cost reduction

  • Implemented runtime metrics with NewRelic, DataDog, OpenCensus, Lightstep, Jaeger

  • Improved speed of Gitlab CI/CD pipelines for K8s Helm deployments

  • Golang services in for billing, accounting, invoicing, pricing, quoting in distributed multi-region system: golang/echo.v4, dynamodb/single-table

  • Improved security by implementing features like 2FA/MFA, SSO, reCaptcha, rate-limiting ...

  • Contributed to complex CPQ Quoting and Pricing project: enterprise B2B pricing modeling

• Head of Engineering www.tandem.net, Tripod Technology GmbH

  Jun, 2016 - Feb, 20225 years 8 months

  Leadership and hands-on role, 1M DAU, 12+ Engineers, 50+ employees, education domain. Microservices applications, grow & manage team, analytics, business continuity. Building and running software at scale.

  • Coordinated project delivery with Product, Marketing, Community departments

  • Evaluated projects and features requirements, checked designs and architecture of the software product

  • Coordinated projects for cross-functional engineering team

  • Evaluated engineers performance, coached and mentored engineers in technologies and career development

  • Scaled backend infrastructure from 1000 RPM to 80000 RPM, from 100kDAU to >1mDAU and <50ms API response time

  • Scaled backend capacity from 1000DAU to >15M users

  • Applied cost savings plans and utilized AWS Spot instances to reduce costs by 32%

  • Hired multiple Frontend, AI/ML, Data, Backend and devOPS engineers.

  • Migrated monolithic backend application into 15 independent services

  • Introduced Golang & AWS Keyspace/Cassandra, DynamoDB for high-load group chat application storage

  • Promoted AWS Best Practices, executed AWS Well-Architected framework together with AWS solution architects

  • Maintained all business infrastructure of >40 EC2 servers across 3 AWS regions, migrated from AWS EC2 Classic to AWS VPC

  • Updated codebase from PHP5 to PHP 7.4, Go 1.14 Docker 19, PHPUnit 9

  • Supervised development of serverless microservices in Golang & DynamoDB

  • Split mono-repository into >30 separate repositories with separate CI/CD

  • Executed multiple refactoring projects in code, infrastructure, raw storage and databases

  • Maintained backend roadmap and technology radar tech-radar.opensource.tandem.net based on ThoughtWorks

  • Improved user retention analytics, subscriptions and overall revenue tracking

  • Updated real-time messaging server RabbitMQ, secured authorization, added 3rd websocket/MQTT browser client

  • Added support for in-app purchase gifting, subscription hold, grace periods, geo-search.

  • Increased application infrastructure and performance/APM monitoring automation and alerting via NewRelic

  • Built full CI/CD pipeline on AWS Pipeline inc. Blue/Green deployments and AWS ASG/AutoScaling

  • Improved China & SEA connectivity via transparent HAProxy, ICP/Hosting issues resolved

  • Built internal business KPI, retention, engagement and revenue tracking systems

  • Enforced PHPUnit & integration testing, code reviews & code style policies

  • Migrated application services into containers (Docker)

• Senior Software Developer www.tandem.net, Tripod Technology GmbH

  Jun, 2013 - Jun, 20163 years

  Mature backend solutions for audio/video (tele)communications software. Developed public API for mobile clients.

  • Implemented public API for native mobile clients

  • Refactored old MVP prototype codebase

  • Launched first production release 1.0

  • Celebrated first 50 users sign-up on GA and first promotions on iTunes

  • Deprecated legacy on-premise hosting and migrated into AWS EC2-Classic

  • Celebrated '2015 Most innovative app of the year' award (Apple iTunes)

  • Implemented PHP framework with open-source components

  • Reduced API response times from >=2000ms to ~100ms

  • Implemented critical app functionality: in-app messenger, real-time chat, community live feed, email-reminders, user search and more

• Lead Software Developer meetville.com, Yangutu LLC

  Nov, 2011 - Nov, 20121 year

  Working on web based social network.

  • Added API for supporting external 3rd party Game-platform add-on's

  • Added AMF Flex/ActionScript API Server for import/export of data to mobile platform

  • Added Facebook, Instagram, VK and other social networks integrations

  • Extended user data import and export API's

• Software Engineer www.eharmony.com, eHarmony, Inc

  Aug, 2008 - Sep, 20113 years 1 month

  eHarmony Reporting and Management Tools for Risk Management team.

  • Developed CMS/RMS Internal service from specification to manage and automate risks and fraud detection

  • Working with sensitive client payment information

  • Extended CMS/RMS service with flexible and configurable multi-role authentication system for different regions

  • Added support for localization and translation of CMS/RMS

  • Added analytics and audit tools for tracking and optimizing team (users or the CMS/RMS) performance

• Software Engineer at IponWeb www.iponweb.com, IponWeb

  Aug, 2007 - Sep, 20114 years 1 month

  SOAP/Rest API for real-time AD Exchange platform - RightMedia

  • Developed on SOAP-API for high-load real-time Ad platform at big scale

  • Heavily extended and rewrote existing functional test coverage, integrational e2e testing

  • Covered new edge cases in tests which lead to fixes in critical API parts

• Software Engineer at Yahoo! yahoo.com, Yahoo!

  May, 2008 - Mar, 200910 months

  AD Exchange API - RightMedia

  • Refactoring tests, code and documentation, working with remote Yahoo developers team. SOAP API. Perl. PHP5

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