A non-exhaustive list of realisations
DevOps
Containerisation of application using Docker
Set up Mesos (similar to Kubernetes) datacenter-as-a-service
Complete automation of (virtual) machines deployment using Foreman (similar to Terraform) infrastructure-as-code
Set up continuous deployment pipelines with Jenkins, from GIT to production
Developement
REST API with Flask, Django or AioHttp (asynchronous)
Low-level industrial software, implementation of communication protocol
Application level proxy, to plug a new componement in an exisiting workflow or add an authentication layer
Automate any kind of task: monitoring script, third-party supplier data import, “homemade” ETL pipeline
Treatement of your data like timeseries resampling or model fitting (datascience with pandas/scipy)
Infrastructure
Migration of Linux servers RedHat/CentOS or Debian/Ubuntu
Keep machines in nominal state using and deploy them new roles using Puppet (similar to Ansible, Chef) infrastructure-as-code
Installation and set-up of any kind of services (NGINX reverse proxy, router, application server, database, syslog, backup)
Set-up ElasticSearch, MongoDB or HDFS clusters
Application packaging using DEB or RPM, or Windows NSIS
Machine learning stack packaging to deploy it (TensorFlow, PyTorch, CUDA support)