Tom is available for hire

Tom Feron

Verified Expert in Engineering

Full-stack Developer

Location

Tallinn, Estonia

Toptal Member Since

July 20, 2020

Tom is a senior developer with several years of experience building web applications in their entirety—from the user interface to the servers—at large companies such as Nature and startups like Habito or Scrive. Tom joined Toptal because he was interested in freelancing and wanted additional opportunities to learn more. Tom specializes in back-end development, especially using Haskell and DevOps on cloud platforms, but is keen on working with whatever tools best fit the job.

Linux Haskell PostgreSQL Microservices Kubernetes Vuex CQRS Terraform Python OCaml Docker TypeScript Vue Unix Ruby NixOS Spock

Portfolio

Habito

Amazon Web Services (AWS), Servant, Unix, Terraform, Kubernetes, Event Sourcing...

Scrive

Amazon Web Services (AWS), React, Unix, PostgreSQL, Haskell

Optinomic

Angular, Servant, Spock, HL7, Docker, Linux, PostgreSQL, Haskell

Experience

Linux - 8 years PostgreSQL - 6 years Haskell - 6 years Servant - 4 years Kubernetes - 2 years Vuex - 2 years Vue 2 - 2 years NixOS - 2 years

Availability

Part-time

Preferred Environment

Microservices, Terraform, Event Sourcing, Unix, Vue, JavaScript, TypeScript, Docker, Kubernetes, PostgreSQL, Linux, Haskell

The most amazing...

...app I've developed was an innovative healthcare platform used by psychiatrists to keep track of a patient's progress by compiling data into graphs and reports.

Work Experience

Senior Software Engineer

2019 - 2019

Habito

Helped to break the monolith into independent microservices running on Kubernetes.
Improved the CQRS and event-sourcing implementation to make it more efficient.
Added Prometheus instrumentation to microservices and created Grafana dashboards to monitor production.

Technologies: Amazon Web Services (AWS), Servant, Unix, Terraform, Kubernetes, Event Sourcing, CQRS, PostgreSQL, Haskell

Back-end Developer

2018 - 2019

Scrive

Added features to the core product in Haskell and to the front end with React.
Created a Nix development environment so that new developers would only have one dependency to install and everybody runs the same versions of all dependencies.
Abstracted the S3 integration to add an LRU cache and make tests run the same code without actually reaching the network.

Technologies: Amazon Web Services (AWS), React, Unix, PostgreSQL, Haskell

Developer (Consultant)

2014 - 2018

Optinomic

Implemented a way for users to extend the platform by writing their own apps.
Rewrote the whole platform after it became clear that the initial requirements were wrong while gradually migrating all the data to the new version without impacting production.
Integrated with other management systems using the HL7 messaging standard for medical data.

Technologies: Angular, Servant, Spock, HL7, Docker, Linux, PostgreSQL, Haskell

Developer

2012 - 2014

Nature Publishing Group

Added new features and integrated other applications with Nature Publishing Group's science-focused job platform.
Developed an experimental recommendation engine to find the most relevant reviewers for new research papers—drastically reducing the amount of time needed to organize peer reviews.
Helped improve security by searching for and fixing security vulnerabilities in various systems developed by the company.
Developed a prototype of a web application to explore the contents by traversing the graph of relations between entities using semantic web technologies like RDF, SPARQL, and Triplestores.

Technologies: Elasticsearch, Microsoft SQL Server, Puppet, Haskell, Ruby on Rails (RoR), Ruby

Experience

Optinomic

https://www.optinomic.com

A healthcare platform for mental health practitioners at hospitals to manage patients, collect data through surveys, and display graphs and other reports to visualize a patient's progress. The platform is extendable through apps that users can write.

Skills

Libraries/APIs

Vue 2, Vuex, Vue, React

Tools

Terraform, Puppet

Platforms

Linux, Kubernetes, Docker, Unix, Amazon Web Services (AWS)

Languages

Haskell, Python, OCaml, TypeScript, JavaScript, Ruby

Storage

PostgreSQL, Microsoft SQL Server, Elasticsearch

Paradigms

Microservices, CQRS, Event Sourcing

Frameworks

Ruby on Rails (RoR), Spock, Angular

Other

NixOS, Servant, HL7

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