Consultant for -

Spark ecosystem - Core, SQL, Streaming, mlLib, R
Hadoop ecosystem - HDFS, YARN
Messaging - Akka, RabbitMQ, Kafka
Scripting - BASH, Python, Ruby, Groovy 
OS - Debian, Ubuntu, CentOS
Cloud Native - Docker, Kubernetes, Mesos, Istio
CICD - Chef, Ansible, Jenkins
Test frameworks - Cucumber, Expect, Robotframework, Google Test
Languages - C, C++, Rust, Python, Ruby, JRuby, Java, Groovy, Scala, Go (Golang)
Web frameworks - Rails, GWT, Node.js, Express, React, Sinatra, Scalatra, Flask, Django
Cloud Providers - AWS, GCP, Azure
Data science, ML, AI