Jano is available for hire
Hire JanoJano Suchal
Verified Expert in Engineering
Ruby on Rails (RoR) Developer
Bratislava, Bratislava Region, Slovakia
Toptal member since March 24, 2014
Bio
Jano is a tech lead, full-stack developer, and founder specializing in web development. He has worked on terabyte-scale database services with government data, recommendation engines, and performance optimization projects. Jano has worked with startups, consulting firms, and led small teams. He has successfully led the development of multiple products and services. Jano holds 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
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).
- Created complete product portfolio and product strategy for company.
Technologies: Amazon Web Services (AWS), Jira, PostgreSQL, Elasticsearch, Ruby on Rails (RoR), Redis, CTO, Full-stack, Web Development, Business Intelligence (BI), Technical Leadership, Technical Writing, Data Analysis, Software Architecture
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. Responsible for development of movie recommendation engine, search engine and search engine analytics subsystems development. Created a spin-off product for search analytics.
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 300,000 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
http://www.foaf.skThis site downloads, cleans, and updates data about over 300,000 companies and 500,000 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 a network (graphs) for deeper insights. It is used heavily by the public and private sectors and handles traffic of over 500,000 page views per month.
API for Slovak Government Data
https://ekosystem.slovensko.digitalAn API for retrieving cleaned, reconciled, and merged data scraped from various public datasets and registers containing millions of records. Created a complete product from scratch and sold to external consumers.
SearchD/Luigis's Box
https://www.luigisbox.com/Search analytics platform collecting and evaluating millions of events in real time. Created a spin-off product for search analytics integrated into major e-shops in Slovakia. Scaled to millions of requests per month.
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.
It identifies conflicts of interests between various stakeholders of the project by analyzing relationships within data.
Garelic
https://github.com/jsuchal/garelicA 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
Coursework Toward a PhD 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, Business Intelligence (BI)
Platforms
Salesforce, Linux, Amazon Web Services (AWS), Docker
Storage
Elasticsearch, Redis, PostgreSQL, MySQL, Sphinx Search Engine, Polyglot Persistence, Database Architecture
Other
API Integration, APIs, Machine Learning, Recommendation Systems, Full-stack, Consulting, CTO, Analytics, University Teaching, Technical Writing, Course Development, Web Development, Technical Leadership, Data Analysis, Software Architecture, Artificial Intelligence (AI), Data Governance, Data Quality, Database Optimization, Web Crawlers, Large-scale Web Crawlers, Product Development, Data Analytics, Search Engines
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