Jano is available for hire

Jano Suchal

Verified Expert in Engineering

Software Developer

Bratislava, Bratislava Region, Slovakia

Toptal member since March 24, 2014

Expertise

SQL Ruby on Rails Ruby Agile Development PostgreSQL Elasticsearch Redis Full-stack Interim CTOs MySQL Linux Machine Learning Recommendation Systems

Bio

Jano is a full-stack developer and founder specializing in databases. Using PostgreSQL, he has worked on database services with government data, recommendation engines, and performance optimization projects and has experience with startups, consulting, and leading small teams. Jano has a master's degree (summa cum laude) in software engineering from the Slovak University of Technology in Bratislava.

Portfolio

Slovensko.Digital

Amazon Web Services (AWS), Jira, PostgreSQL, Elasticsearch, Ruby on Rails (RoR)...

minio, s.r.o.

JavaScript, Redis, Elasticsearch, PostgreSQL, Ruby on Rails (RoR), Full-stack...

SearchD/Luigi's Box

SaltStack, PostgreSQL, Redis, Elasticsearch, Ruby on Rails (RoR), Full-stack

Experience

Ruby on Rails (RoR) - 8 years
Ruby - 8 years
Object-oriented Design (OOD) - 7 years
JavaScript - 5 years
PostgreSQL - 5 years
Linux - 4 years
Elasticsearch - 2 years
Redis - 2 years

Availability

Part-time

Preferred Environment

Linux, PostgreSQL, Ruby, Agile Software Development

The most amazing...

...things I've built are apps using public data in Slovakia, making contracts and public registers easier to use for journalists and the general public.

Work Experience

Lead Developer and Project Manager

2015 - PRESENT

Slovensko.Digital

Led a small team of developers and freelancers to build parallel, low-cost e-government services.
Created a platform for downloading/cleaning public open data sets with millions of entries and gigabytes of data.
Built a fast autocomplete search based on Elasticsearch.
Managed multiple servers serving staging/production environments with Docker-based deployment.
Supported various tools needed for business (Trello, Jira, email servers, billing, AWS).

Technologies: Amazon Web Services (AWS), Jira, PostgreSQL, Elasticsearch, Ruby on Rails (RoR), Redis, CTO, Full-stack

Owner

2011 - PRESENT

minio, s.r.o.

Created a platform for scraping various public government registers and databases.
Built a platform for automatic data disambiguation, cleaning, and reconciliation of multiple messy public datasets.
Managed traffic/performance analytics for several projects.
Built a platform for making government contracts transparently available for anyone in Slovakia.
Managed a search engine with 600,000+ documents (TBs of raw data).
Organized a monthly polyglot developer meet-up in Bratislava every month since 2011.
Created a system for fraud detection in European Social Fund project proposals.

Technologies: JavaScript, Redis, Elasticsearch, PostgreSQL, Ruby on Rails (RoR), Full-stack, Polyglot Persistence

Senior Developer

2013 - 2015

SearchD/Luigi's Box

Created a scalable log processing pipeline analyzing millions of events.
Designed advanced metrics and reports for testing and evaluation of real-world search engines.
Contributed to the full stack—from business goals through front-end tuning to back-end development and tuning.
Ensured high code quality by enforcing automatic testing on the build server, code coverage trend reporting, and code reviews.
Proposed and successfully implemented business process changes to optimize signup and onboarding funnels, yielding an increase in goal conversions.

Technologies: SaltStack, PostgreSQL, Redis, Elasticsearch, Ruby on Rails (RoR), Full-stack

Senior Back-end Developer

2011 - 2013

SynopsiTV

Created a recommendation engine for movies and television shows.
Built a logging and quality evaluation platform for a recommendation engine and search-related sub-projects.
Proposed and measured several UX enhancements on user-facing pages.
Created a crawling service scraping data from various online sources.
Implemented various duplicate matching algorithms for cleaning and disambiguating data.

Technologies: PostgreSQL, Redis, Elasticsearch, Ruby on Rails (RoR)

Founder

2010 - 2012

Foaf.sk

Created and sold a project to download, clean, and update data about over 300,000 companies and 500,000 people from the official registers of Slovak companies, public procurement, debts, internet domains, and other public data.
Supported a complex site handling over 500,000 page views a month.
Created a framework for scraping, cleaning, and merging messy datasets.
Built various visualizations and aggregation reports from gathered data.
Fine-tuned autocomplete search for highly relevant instant responses.

Technologies: Sphinx Search Engine, MySQL, Ruby on Rails (RoR), CTO, Full-stack

Researcher | PhD Student

2008 - 2011

Faculty of Informatics and Information Technologies

Built a news recommendation engine for the largest Slovak newspaper peaking at 3,000+ rpm.
Created and led a new course on full-stack web development.
Published multiple articles on recommendation systems and data mining.
Led multiple teams of students on various projects.
Built and supported various faculty websites and apps.

Technologies: SQL, R, Ruby on Rails (RoR), Ruby

Contractor

2001 - 2011

Freelance

Built a "did you mean?" search feature for a major music website in Slovakia.
Built and maintained web applications for various SMEs.
Consulted several clients regarding SQL performance fine-tuning.
Created a popular random text generator for designers.
Handled basic HTML/CSS work for various clients in the eCommerce sector.

Technologies: PostgreSQL, MySQL, JavaScript, Ruby on Rails (RoR), PHP

Experience

SynopsiTV

Movie and TV show recommendation system and social site.

Open Contracts

A crowdsourcing platform for searching and analyzing government contracts. It provides a much more usable interface to work with contracts of Slovak governmental organizations in comparison to the official government site. It downloads and processes over 300k scanned documents (over 1TB of raw data) in various formats from many sources and transforms them into an easily searchable format using full text and advanced faceted search. Contracts are automatically analyzed and assigned a score indicating how problematic the contract is. This analysis is based on the rules managed by portal administrators.

Social Network of Slovak Companies

This site downloads, cleans, and updates data about over 300k companies and 500k people from official registers of Slovak companies, public procurements, debts, internet domains, and other public data. It shows all current and historic data about companies in an aggregated and usable form. It visualizes connections of people and companies as network (graphs) for deeper insights. It is used heavily by the public and private sector and handles traffic of over 500k page views per month.

API for All Slovak Government Data

https://ekosystem.slovensko.digital

An API for retrieving cleaned, reconciled, and merged data scraped from various public datasets and registers.

SearchD/Luigis's Box

https://www.luigisbox.com/

Search analytics platform collecting and evaluating millions of events in real time.

Fraud Detection in European Social Fund Project Proposals

This crawls a legacy internal project management system and collects data about projects. It features enrichment of this data from other external sources: Slovak company register, register of NGOs, and the statistical office of the Slovak Republic. It involves extensive data cleaning, reverse duplication routines, and heuristics to match and distinguish subjects.

It identifies conflicts of interests between various stakeholders of the project by analyzing relationships within data.

Garelic

https://github.com/jsuchal/garelic

A Google Analytics gem for Rails application performance that works by passing request profiling and timing data into Google Analytics. Also, allows performance analysis in Google Analytics and finding bottlenecks.

Education

2007 - 2011

PhD (Unfinished) Degree in Machine learning

Slovak University of Technology - Bratislava

2005 - 2007

Master's (Summa Cum Laude) Degree in Software Engineering

Slovak University of Technology - Bratislava

2001 - 2005

Bachelor's Degree in Informatics

Slovak University of Technology - Bratislava

Skills

Libraries/APIs

X (formerly Twitter) API, Facebook API, jQuery, GitHub API, Sidekiq

Tools

RSpec, SaltStack, Jira, Git, GitHub, RubyMine

Languages

Ruby, SQL, PHP, JavaScript, R, CoffeeScript, HTML5

Frameworks

Ruby on Rails (RoR), Sinatra

Paradigms

Agile Software Development, Test-driven Development (TDD), Object-oriented Design (OOD), Behavior-driven Development (BDD), Dependency Injection

Platforms

Salesforce, Linux, Amazon Web Services (AWS), Docker

Storage

Elasticsearch, Redis, PostgreSQL, MySQL, Sphinx Search Engine, Polyglot Persistence

Other

API Integration, APIs, Machine Learning, Recommendation Systems, Full-stack, Consulting, CTO, Analytics

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