CV: Ernestas Poškus

Last modified: 2019-10-10

Pragmatic & Ambitious

Keen interest in service oriented architecture, massive scalability, distributed systems, Search Engines.

Blog: http://out13.com
Goodreads: 42270834-ernestas-poskus
GitHub: ernestas-poskus
Twitter: @ernestas_poskus

Open Source

https://github.com/AnsibleShipyard release manager/contributor of major Ansible playbooks (Zookeeper, Mesos, Marathon, etc.)
https://github.com/linkosmos author of 10+ Golang packages
https://github.com/ernestas-poskus/ansible-prometheus Ansible playbook for installing Prometheus monitoring system
https://github.com/vinted/chef-proxysql Chef cookbook for installing ProxySQL with automatic propagation of on disk configuration
https://github.com/pagescrape author of Rust crates
https://github.com/vinted/chef-vitess Chef cookbook configures Vitess clustering system through custom Chef resources.
https://github.com/vinted/chef-clickhouse Chef cookbook configures ClickHouse distributed column-oriented DBMS

Technologies

Rust (Tokio, Futures, Iron, Rocket, Gotham, Actix), Golang (Revel, Gorilla, Beego), Ruby (Ruby on Rails, Grape, Sinatra), PHP (Laravel, Symfony, Wordpress)
Web: JavaScript (Vue, Nuxt), TypeScript, LESS, SCSS, SASS, HTML5
Infrastructure as a Code: Chef, Ansible, Puppet
Cloud services, AppEngine, AWS, Alibaba Cloud, DigitalOcean
Relational databases: MySQL, PostgreSQL, ClickHouse
Non relational databases: Elasticsearch, Memcached, Mcrouter, Redis, Cassandra, ScyllaDB, MongoDB, ArangoDB, RocksDB, OrientDB
Monitoring: Prometheus, Sensu, NewRelic, DatadogHQ
Streaming: Kafka, ZMQ, NSQ
Orchestration: Apache Mesos, Apache Marathon, Kubernetes
Other: Linux, gRPC, GraphQL, ProxySQL, Apache Mesos, Apache Marathon, Nginx, Zookeeper

Engineering Posts

http://engineering.vinted.com/2018/04/09/visualizing-physical-hardware-costs/ Visualizing physical hardware costs
http://engineering.vinted.com/2017/09/18/elasticsearch-more-nodes-with-fewer-servers/ Running 4x instances of Elasticsearch using NUMA
http://engineering.vinted.com/2017/06/05/sharding-out-elasticsearch/ scaling Elasticsearch by sharding out using metrics as guidelines
http://out13.com technical blog

Experience

Staff Engineer @ Vinted

Peer-to-peer marketplace for women and men to sell, buy and swap clothes.

April 2019 – present

Led numerous technical projects
Coordinated teams by distributed technical tasks
Coached junior and midule level peers
Contributed to technical designs of various technical projects

SRE @ Vinted

Peer-to-peer marketplace for women and men to sell, buy and swap clothes.

June 2016 – present

Introduced technologies: Consul, YouTube Vitess MySQL database clustering, ClickHouse, ProxySQL, Cumulus Linux
ProxySQL: automatic query rules service and dynamic weights for follower replica reads
Elasticsearch segments automatic optimization with merging and expunging
Junior peers training
Chef, Ansible infrastructure as a code
Improved continuous deployment speed
Adopted Systemd in all company custom services
Elasticsearch cluster management, breaking changes upgrading: 2.x, 5.x, 6.x
Cache layer supervision, high availability Memcached cluster using Facebook mcrouter
Created automatic registration service for all basic server resources to asset management system for data center
Scaled Elasticsearch cluster to 540 nodes from 135 physical servers

CTO / Full stack engineer @ Linkosmos

Web auditing platform providing automatic SEO improvement recommendations

September 2015 – April 2016 (8 months)

Created distributed system that ran on bare metal servers using Apache Mesos.
Used Apache Marathon on top of Mesos for docker containers orchestration.
Crawled over billion websites using custom Golang web crawler.

Open sourced over 10+ Golang packages: https://github.com/linkosmos

Backend developer @ Vinted

Peer-to-peer marketplace for women and men to sell, buy and swap clothes.

October 2015 – June 2016 (9 months)

Elasticsearch: researched Lucene internals and development more efficient queries
Content balancing: ranking of docuemnts, scoring functions, monitoring of results
Merchandising tools development & integrations with API's

Software developer @ Vinted

Peer-to-peer marketplace for women and men to sell, buy and swap clothes.

April 2014 – October 2015 (1 year 7 months)

Collaborated with frontend teams
Optimized website SEO and did various organic traffic optimizations
Created instant buy functionality (anonymous buying)
Developed SERP ranking algorithm
Wrote first standalone service in company using Ruby Sinatra framework
Item Score - onsite scoring items on numerous facts and offsite social data retrieval from API’s

Software developer @ OXID eSales AG

Large Scale Web E-shops Development for Germany & neighbor countries.

June 2013 – April 2014 (11 months)

Was outsourced for German company OXID eSales AG, worked at OXID Professional Services team.
During the time developed several cross-shop modules like: custom sorting by categories (with possibility to save state), payment modules, caching module for expensive SQL queries,
deployment scripts to staging/live systems and more project specific modules.
Made Web Deployment UI with AJAX, Drag & Drop based on: Git Log and Git Diff for package deployment system.

Learned a lot about Scrum and Agile software development, project management and estimation.

Expanded knowledge about server-architectures, complex SQL queries, server monitoring, deployment strategies, caching methods and scaling.

Education

2011 - 2015

International Business School at Vilnius University

Bachelor of International Business, International Business

Micro/Macroeconomics
Business Mathematics
Business Psychology
Civil & Commercial Law
Management History and Theory
International Protocol
Financial Accounting
Organizational Structures
Business Statistics
Project Management
Financial Markets and Investments
International Economics and Euro-Integration
Quantitative Analysis of Economics
Financial Management
Quality Management
Communication Management of Organizations
Knowledge Management and Innovations
Fundamental of International Negotiations

2010 - 2012

Vilnius Gediminas Technical University

Bachelor of Engineering Informatics, Information Technology

Programming: C, C++
Integral & Differential Calculus
Discrete Mathematics
Computer Graphics
Algorithms and Data Structures
Operating Systems

Online Education

2015

University of Illinois at Urbana-Champaign

Cloud Networking, 80.0%
Cloud Computing Concepts part 2, 94.3%
Cloud Computing Concepts, 85.4%
Cloud Computing Applications, 93.3%

2014

University of Washington

Programming Languages, Software Engineering, 85.9%
SML, Racket and Ruby

Languages

English (Native or bilingual proficiency)
Lithuanian (Native or bilingual proficiency)
Russian (Native or bilingual proficiency)