Portfolio

tadej krevh
Name: Tadej Krevh
Postal Address: Pod Gonjami 110, 2391 Prevalje, Slovenia, Europe
Telephone: 00386 41 754 245
Email: tadej@krevh.com
Date of Birth: 6 February 1978
Place of Birth:Slovenj Gradec, Slovenia
Nationality:Slovenian
Sex:Male
Marital Status: Married
Children: 2
Mother Language: Slovenian
Other Active (written&spoken) Languages: English, German, Croatian
Driver’s license: A,B
Criminal offences: None
Health: Excellent
Education: Udacity Front End Web Development Nanodegree 2016, Software Enginnering science at University of Maribor, Information Technologies High School

 

WORK EXPERIENCE

Everyday Magic (2016…), Remote, New York

Title : CTO / Senior Lead Full Stack Engineer

https://forksmealplanner.com

Lead engineer of a distributed small team for a responsive meal planner web application. (Re)architetured/redesigned, optimized and scaled the system from 1300 to 160.000+ users.

Scaleable backend on Heroku/Hirefire:
– Python/Django REST API
– Nginx with Gunicorn
– PostgreSQL
– Redis
– Celery
– Stripe payments
– Paypal mass payouts
– Amazon S3 storage

Frontend:
– AngularJS
– Responsive design
– Foundation
– Karma/Mocha
– Protractor
– Intercom
– Mixpanel
– Fullstory
– Gulp

Other technologies involved:
– Git
– Zeplin
– Countdowntimer
– Candy Referral
– Mixpanel
– JIRA

Achievements:
– increased backend test coverage by 170%

– prepared front end testing framework and initial tests

– introduced continuous integration, opbeat error reporting and
automatic scaling of backend servers for smooth operation during traffic spikes

– seamlessly transitioned backend and frontend to signing up without credit card and architectured the logic to incorporate sample plan and recipes for free users

– made myself available outside working hours/during the night and also over the weekends to ensure success of the company

– fixed the architecture of backend and frontend, so frontend now contains less business logic

– sped up various backend API endpoints by over 1000%

– sped up parts of backend admin interface by means of caching, prefetching and query optimizations

– improved and sped up recipe and ingredients searching by migrating to ElasticSearch instead of using SQL queries

– sped up the meal planner frontend by over 700% via optimizations and refactoring of the code in AngularJS by studying AngularJS in details in my private time

– analyzed and fixed other front end performance problems, like recipes and dashboard image compression

– sped up weekly plan email sending by over 2300%

– got rid of node.js server which, during frontend updates to notify connected clients to reload, spiked the traffic on backend and made the app unresponsive for several minutes

– engineered release versioning system so users are notified when they are using an out of date application version (to replace the node.js brittle solution above)

– engineered dashboard versioning system, so users are notified when they are trying to change stale data

– monitored work done by co-workers and suggested improvements, good coding practices and architecture changes, leading to less bugs and better maintainable code

– suggested ways and ideas how to standardize the product, so it could be used for other diets in the future

– suggested, architectured and developed the subscription discount system

– continously monitored and optimized our backend systems to keep up with increased traffic and to keep users happy and decrease churn

– actively participated in the hiring process of candidates for front end engineer position and on-boarding of our new hire

– continuously seek better solutions, architecture and UX designs to improve the meal planner and help keep the users happy and grow the revenue of the company

– learning new technologies (React + React Native) in my free time, in order to evaluate the possibilites to migrate to a newer, more performant framework

– built a fully fledged affiliate system with click tracking, commisisons calculations, monthly statements, mass payouts via PayPal, connected via webhooks to Stripe, etc…

 

I also wrote an article about the optimizations:
https://www.linkedin.com/pulse/rest-api-backend-optimization-heroku-tadej-krevh

 

JOBUBA International Group GbR (2016…), Remote, Germany

Title : Co-founder CTO / Senior Lead Full Stack Engineer

http://jobuba.com

CTO and full stack development of new social real time job platform, helping those in need and those who need help.

Backend:
– Python/Django
– Rest API
– Elastic Beanstalk, RDS, ElastiCache, EC2, Load balancer
– Celery
– Redis
– Braintree payments
– S3 static asset storage
– FCM push notifications
– FB Graph integration
– Google geolocation API
– Automatic PDF invoice generation

Frontend:
– Angular4 with TypeScript
– RxJS
– JWT
– Webpack
– Bootstrap (Responsive)
– CloudFront

Android app:
– React Native

 

TIK, Tadej Krevh s.p. (2005-2016), Pod Gonjami 110, 2391 Prevalje, Slovenia, Europe

http://www.krevh.com/

Working as freelancer on different projects for company Epilog involving Java, Angular, Python/Django, PHP, J2EE, Oracle, PostgreSQL, MySQL, ….

FJA OdaTeam d.o.o.  (2002-2005), Slovenia, Europe

http://www.fja-odateam.com/

At OdaTeam we were working with Smalltalk and JAVA with strong emphasis on object oriented programming (OOP) and extensive use of design patterns. OdaTeam is developing life/non-life insurance and investment software called SymAss for European insurance companies. I was in charge of developing a sophisticated document definition subsystem, analysis and later implementation of Smalltalk driver for Oracle Call Interface, needed for purposes of using relational database with SymAss product and played a key role in implementation of parallel/distributed migration of data from internal object DB to Oracle and parallel processing of business batch processes.

Company was divided into 3 teams, I was the lead programmer in the Frameworks team where we were developing different kinds of frameworks so that business logic developers did not have to worry about lower layers. It was an Agile working environment, where we were practising extreme (XP) programming on all levels of development and its life-cycle with 2 week sprints, daily standup meeting, task board, etc. It wasn’t called Agile back then yet.

 

HERMES SoftLab d.d. (1998-2002), Slovenia, Europe

http://www.hermes-softlab.com/

now known as

http://www.comtrade.com/

I started my career at Hermes SoftLab as part of the Universitys 2 months mandatory practice. As I didn’t know Java yet at that time, I was given a role of a tester. I didn’t really like to follow scripts and click around the software in search of bugs. So I spent long hours, mostly from 9am to midnight, at the office learning Java and eventually, after 2 weeks (I was already very proficient with Pascal, C/C++ and assembler at that time) I was promoted to software developer. For the first 2 years I was working on Windows and Unix (Solaris and HP-UX) platforms, with first project being HP OpenView VantagePoint Java GUI plug-in project. I was learning ins and outs of professional software development and my tasks included writing new functionality, fixing existing code, writing documentation and testing in a team of about 5-6 people. The project duration was 1 year and was successfully completed. I was mostly programming in Java for the client-side (client/server communication and Java GUI/Swing), and C/C++ on the server side.

My next project was integration of HP OpenView IT Operations (now known as VantagePoint) with Sun Management Center 3.0 which also took about 1 year and was done completely by myself. The project kicked off with my visit to the Hewlett Packard, Germany, where I met with the client and collected all the requirements, and also communicated with Sun USA for additional information, producing all the required pre-development documentation and then code, test, package up and document the whole system, which went successfully into production. On this integration project I was working with Java, including technologies like RMI, JNI and some shell scripts on Solaris platform.

The next 1.5 year I worked with C/C++ on Windows platform and also got promoted to lead engineer in our team on project OpenView for Windows. We were programming WMI dynamic data providers using C/C++ on Windows, involving lots of technical design documentation.

Additionally I also worked on prototype projects using tools and technologies like .NET, C#, ASP.NET (mobile ASP.NET, deploying net agents via WAP through a cell phone); C & OpenGL demo for applixRay and some others.

In year 2000, I also attended WinSummit 2000 conference held in Davos, Switzerland, where .NET was introduced to mass public for the first time. As a consequence I later held two in-company presentations about .NET as it was a complete novelty at that time.

 

MISC SMALL PROJECTS

There are also some other projects I worked on:

– Query optimization and caching to speed up the API Endpoints for a Silicon Valley Startup (Django query optimization, Redis caching). Managed to reduce number of queries and response times by over 300% via optimization and as much as 100x via caching.

– Generation of HTML Ad banners (of various sizes) from XML (PHP, XML, JQuery, Smarty)

Cebelca.biz API integration for Invoice generation for eCommerce website (PHP, Cebelca.biz API)

OpenCart + Datastudio Poslovanje integration via Webservice (PHP, MySQL, SOAP Webservice)

– Python + Django application (published on github), that pulls images under given #hashtag from Twitter every 20min and should be made available through album accessible via browser or via REST API (Python, Django, Twitter API, Facebook API, PyPi)

Flying club logbook  (logbook entry via web and mobile, statistics, reports, reservations, billing,..). (Python, Django, AJAX,PostgreSQL, Nginx, AWS EC2 & S3, South, data migration from legacy system,…)

– Provided all the back end programming for website http://www.condorspot.com (Python, Django, MySQL, Image manipulation, …)

– Developed back end for realtime sailplane tracking system for LXNav (PHP, JSON, MySQL, Javascript, GoogleMaps API, …)

– Working in a team of two on a solution for GPS tracking of vehicles over GPRS (Delphi, MS SQL, …)

– Wrote a couple of communication protocols for flight logger devices for company Naviter (C/C++, …)

– Improved and added some functionality for work time registers for company Ars Informatika (C#, MS SQL, ASP.NET)

– Created a room temperature monitoring application for a Hotel with integrated SMS notifications when some input signal threshold is exceeded. Application also records the data into database and then some interesting reports are made available to the supervisor (ASP.NET, C#, MS SQL), enabling them to cut down on heating costs. Project was completed in a week.

– Wrote an application that was gathering GPS data from a flight simulator, sending it to a remote server which then enabled others to see all the tracked flights in realtime in Google Earth (C#, MySQL, PHP, GoogleEarth, KML/KMZ)

 

ATTENDED SEMINARS:

Technical:  Devoxx, XP2013, WinSummit, TechEd, several Java seminars

Non-technical: Presentation skills, Professional Leadership, ISO 9001, Insights Discovery, Communication skills

SOFTWARE KNOWLEDGE AND EXPERIENCE:

Primary programming languages: JavaScript, TypeScript, JAVA, PHP, Python, KnockoutJS, AngularJS, Angular4, React, React Native, jQuery, C#, C/C++,  PL/SQL, Delphi/Pascal, Smalltalk, Shell scripts, HTML5, CSS3, SASS, LESS, JSP

Operating system platforms: Windows, Linux

Knowledge of software development technologies: Object Oriented Programming, Design patterns, RMI, JNI, SWING, JIDE, .NET, ODBC/JDBC, XML, SOAP, JSON, SQL, PLSQL, Django, Nginx, Apache, JCO SAP IDOC, low level protocols, serial communication, KML, real-time systems, mutithreading, state machines, Agile, Amazon AWS EC2, S3, …

Other software knowledge: IntelliJ Idea, Eclipse, Git, Perforce, Google Earth/Maps, TOAD, Joomla CMS, OpenCart, PrestaShop, Microsoft Office

Database knowledge: Oracle, MySQL and limited experience with some others (MS SQL, Postgres, HQSQL, SQLite, …)

Other relevant knowledge: Since my wife had problems getting a job after our second child, we decided to set up 4 online stores that we are running since mid 2014 and through that I also gained knowledge on e-commerce platforms Prestashop and OpenCart and marketing knowledge using Google Analytics, Google AdWords, Facebook Ads, etc…

Hobbies :-) I love motorsports and soaring. I used to race autocross and was national champion in 2006. I still attend trackdays if time permits it. I also fly with sailplanes since 2002 and paragliders since 1999.  I enjoy flying competitions and try to attend a few races per year.


 

Would you like to hire me for your next project ? 

Please get in touch. You can use the form below:

  • Full Name
  • Email
  • Message

Leave a Reply