Stjepan is available for hire

Stjepan Buljat

Verified Expert in Engineering

GPT Developer

Location

Zadar, Croatia

Toptal Member Since

April 8, 2015

Stjepan has over 10 years of experience in software development and design. He specializes in full-stack reactive Scala applications. As a certified ScrumMaster, he's a Scrum practitioner. He is a passionate Software Developer, communicates extremely well, and has been a part of teams of different sizes.

Java JasperReports Scrum MongoDB Akka Scala SQL Java EE Linux Project Management PostgreSQL Amazon Web Services (AWS)Agile Software Development MySQL Git

Portfolio

Cognism

Amazon Web Services (AWS), AngularJS, Python, Java, Scala

Cognism

Named-entity Recognition (NER), Natural Language Processing (NLP)...

Etna

MongoDB, Akka, Play Framework, JavaScript, Scala

Experience

Java EE - 7 years Scrum - 4 years Project Management - 4 years Scala - 2 years Play Framework - 2 years MongoDB - 2 years Akka - 2 years GPT - 1 year

Availability

Part-time

Preferred Environment

Git, SBT, IntelliJ IDEA, Windows

The most amazing...

...thing I've coded is a service oriented framework for debt enforcement which is used in several large Croatian banks.

Work Experience

CTO

2016 - PRESENT

Cognism

Created a platform for lead prospecting.
Developed a CRM data cleaning service.

Technologies: Amazon Web Services (AWS), AngularJS, Python, Java, Scala

Software Architect

2015 - 2016

Cognism

Created a complex event processing framework.
Designed a complete microservice architecture.
Assisted in project management and development.

Technologies: Named-entity Recognition (NER), GPT, Natural Language Processing (NLP), Generative Pre-trained Transformers (GPT), MongoDB, Play Framework, Akka, Scala

Product Development Manager

2013 - 2016

Etna

Created a web application for processing and visualizing business events coming in from different systems using Scala, Play Framework, Akka, and MongoDB.
Created a system for tracking and managing business processes of emergency medical services using Scala, Play Framework, Akka, and MongoDB.

Technologies: MongoDB, Akka, Play Framework, JavaScript, Scala

Back-end Developer

2015 - 2015

Comcast

Created a back-end API layer for managing various DNS servers like AWS, Route 53, and dnsjava.

Technologies: Amazon Web Services (AWS), dnsjava, spray, Amazon Route 53, Akka, Scala

Software Architect

2013 - 2015

Think You, Inc.

Built a RESTful back-end system used by mobile apps (iOS, Android).

Technologies: MySQL, spray, Scala

Back-end Developer

2013 - 2014

Catchapp

Implemented a cluster system using Akka cluster.
Implemented an autocomplete service using ElasticSearch suggestion feature.
Created a continuous integration system using Jenkins CI.
Migrated an existing database solution to MongoDB.
Integrated the system with Zabbix.

Technologies: Elasticsearch, MongoDB, Akka, Play Framework, Scala

Research and Development Team Leader

2008 - 2013

Etna

Designed and implemented a transactional, modular, and service-oriented framework for a banking application using Java EE and WebSphere AS.

Technologies: IBM Db2, WebSphere Application Server, Java EE

IT Architect

2005 - 2013

Etna

Created a module for printing and sending bank statements to bank customers using Smalltalk and Java.
Created a framework for debt enforcement system within a bank information system using Java EE, WebSphere AS, and DB2.
Created a module for deposits for legal entities within existing bank system using Java EE, WebSphere AS, and DB2.
Created a module for integration to Forex trading system using Java EE, WebSphere AS, and DB2.
Supported a bank payment application using Smalltalk, VAGen, and DB2.

Technologies: IBM Db2, WebSphere Application Server, Java EE, VisualAge Generator (VAGen), Smalltalk

Parallel Programming Technology Researcher

2005 - 2005

University of Zagreb Computing Centre

Research project on parallel programming technologies alternatives.
Created multiple MPI programs showcases which run on the Isabella cluster.
Prepared and held a 3-day course on using MPI on the Isabella cluster.

Technologies: C, MPI

Experience

YouPass

Worked as the Software Architect for this project that developed wearable products that link to your social identity.

Catchapp

Back-end Developer for this service that allows you to follow specific topics on various media outlets.

RapidEMS

Worked as a Project Manager for a project that developed a software system for tracking and managing business processes of the emergency medical services.

Moneta

http://www.etna.hr/portfolio/moneta/

Worked as a Senior Engineer on this project.

Balp

Worked as the Project Manager for this service that focuses on the computerization of banking operations.

Poko

Worked as a Software Architect for this project.

Cognism

http://www.cognism.com

Platform for automated sales leads generation and management

Skills

Languages

Java, Scala, SQL, JavaScript, C, Smalltalk, Python

Frameworks

Akka, Play Framework, AngularJS, Spring

Libraries/APIs

JasperReports, spray, MPI, Twilio API, jQuery, Facebook API, D3.js, LinkedIn API, Twitter API

Paradigms

Scrum, REST, Agile Software Development, Event Sourcing, CQRS, Functional Programming, Functional Reactive Programming

Storage

MongoDB, H2, PostgreSQL, MySQL, Elasticsearch, IBM Db2

Tools

Apple Push Notifications, Eclipse IDE, Git, Sublime Text, Google Cloud Messaging, IntelliJ IDEA, SBT, Named-entity Recognition (NER)

Platforms

Amazon Web Services (AWS), DigitalOcean, Java EE, Linux, Windows, Heroku

Industry Expertise

Project Management

Other

Product Management, Software Architecture, APIs, WebSphere Application Server, VisualAge Generator (VAGen), Amazon Route 53, dnsjava, Natural Language Processing (NLP), GPT, Generative Pre-trained Transformers (GPT)

Education

2007 - 2009

Master's of Business Administration Degree in Business Management

University of Zagreb, Faculty of Economics and Business - Zagreb, Croatia

2000 - 2005

Master's Degree in Computer Science

University of Zagreb, Faculty of Electrical Engineering and Computing - Zagreb, Croatia

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