Dejan Peshevski, Developer in Skopje, Macedonia

Dejan Peshevski

Software Developer

Location
Skopje, Macedonia
Toptal Member Since
June 18, 2020

Dejan is a database architect trusted by numerous corporations worldwide. For over a decade, he did the heavy lifting at the largest banks in Southeastern Europe and then moved on to managing a startup serving clients from the Fortune 500 companies. Dejan specializes in data modeling, data analysis and geospatial but has worked the whole stack of software development, front to back.

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Portfolio

BCG - Gamma
Data Engineering, Amazon Web Services (AWS), Python, Amazon EC2, Redshift...
(LG) GIIR America (HS Ad)
Data Engineering, ETL, Data Pipelines, SQL, JavaScript...
MI-C3
GeoServer, OpenLayers, PostGIS, Node.js, D3.js, JasperReports, TIBCO, AngularJS...

Location

Skopje, Macedonia

Availability

Part-time

Preferred Environment

PostgreSQL

The most amazing...

...piece of work I've done was building a privately hosted collaboration platform aiming to simplify interactions between organizations.

Work Experience

2020 - PRESENT

Lead Data Engineer

BCG - Gamma
  • Implemented the back-end for an AI-driven marketing product, DEEP.AI, by BCG.
  • Deployed the product for RingCentral. Implemented custom modules to support all types of marketing activities.
  • Led the back-end development, database design, API, and ETL.
Technologies: Data Engineering, Amazon Web Services (AWS), Python, Amazon EC2, Redshift, Data Quality, Snowflake, Azure, Python API, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, SQL, Visual Basic for Applications (VBA), PL/pgSQL, PostgreSQL, Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Architecture, Apache Airflow, Database Modeling, Data Architecture, Data-driven Design, NoSQL, Data Analysis, Data Analytics, Excel Macros, Pandas, Data Visualization, Tableau, Amazon S3 (AWS S3), Database Administration (DBA), Scalability, APIs, Relational Database Services (RDS), Data Management, IT Automation, Amazon RDS, API Integration, Dashboards, Unix Shell Scripting, Excel 365, Data Science, Django, CI/CD Pipelines, Big Data, Data Integration, BI Reporting
2020 - 2021

Data Engineer

(LG) GIIR America (HS Ad)
  • Implemented an ML service for tracking marketing offerings from different vendors to give an insight into how effective the vendor campaigns were.
  • Enabled the service to parse the text content of these offerings to identify the key elements like the type of offer, discount, gift, merchandise, and conditions that apply.
  • Made an estimate of the cost of the campaign, which was then compared to the estimated sales and thus gave an insight into how the effectiveness of the campaign.
Technologies: Data Engineering, ETL, Data Pipelines, SQL, JavaScript, Visual Basic for Applications (VBA), PL/pgSQL, PostgreSQL, Node.js, JasperReports, BigQuery, Amazon Aurora, Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Architecture, Database Modeling, Data Architecture, Data-driven Design, NoSQL, Data Analysis, Data Analytics, Excel Macros, Data Visualization, Amazon S3 (AWS S3), Database Administration (DBA), Scalability, APIs, Relational Database Services (RDS), Data Management, IT Automation, Amazon RDS, API Integration, Dashboards, Unix Shell Scripting, Excel 365, Data Build Tool (dbt), Data Science, Google BigQuery, Data Integration, BI Reporting
2011 - 2017

Head of Software Development | Software Architect | Senior Software Engineer

MI-C3
  • Managed cross-functional teams of 30+ software engineers in Malta, Macedonia, and Nigeria offices.
  • Created an environment where everyone could complete their assignments accurately and on time by clearly communicating the task purpose and providing continuous code reviews, training, and assistance.
  • Found, hired, and retained most of the team members by ensuring everyone enjoyed their time with the team. Used every opportunity to inspire everyone to dream big about what they do.
  • Architected and led the early development of a privately hosted collaboration platform, Affectli. Deployed at clients like Chevron and Newmont, and IHS Towers.
  • Built the architecture and led the development of a fleet and shipping management system for Petro Kazakhstan, a CPNC: China National Petroleum Company.
  • Created the system architecture and developed the database of TagNGo (Tagngo.com), a vehicle tracking and onboard diagnostics (OBD) service.
  • Designed and built a back-end infrastructure for simpler and cost-effective microservice development. It is an integral part of all the products developed at MI-C3.
Technologies: GeoServer, OpenLayers, PostGIS, Node.js, D3.js, JasperReports, TIBCO, AngularJS, Activiti BPM, Java EE, PostgreSQL, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, SQL, JavaScript, Visual Basic for Applications (VBA), PL/pgSQL, SAP BusinessObjects (BO), pgRouting, Pentaho, Socket.IO, Java, MongoDB, Amazon Aurora, Spark, Spark SQL, Google Maps API, Express.js, MySQL, Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Architecture, Server Migration, Database Modeling, Data Architecture, Data-driven Design, NoSQL, Data Analysis, Data Analytics, Excel Macros, Data Visualization, Amazon S3 (AWS S3), Database Administration (DBA), Scalability, APIs, Telemetry, Relational Database Services (RDS), Data Management, IT Automation, Amazon RDS, API Integration, Dashboards, Unix Shell Scripting, Excel 365, Big Data, QGIS, ArcGIS, Spatial Databases, Data Integration, BI Reporting
2008 - 2010

Senior BI/Data Engineer

Alpha Bank
  • Supported the implementation of the Basel II regulatory standards by developing statistical models (based on HMM—hidden Markov model) assessing the bank's risk exposure (credit, liquidity, currency, and interest rate risk).
  • Supported the migration to Oracle FLEXCUBE by developing crosscheck reporting to validate the proper configuration and operation of the new system.
  • Built a module that independently generated all the accounting records (and other intermediary tables) based on the configuration and the activity entries originating from all the system modules.
  • This module was a banking system made according to the bank's specifications. It did all the work FLEXCUBE does to the data after the user's input. These records were later compared against the FLEXCUBE ones to check if everything was in place.
  • Developed reporting and ETL related to loans, deposits, funds transfer, and overall accounting.
  • Implemented data analyses in projects that established the local regulatory requirements, converting charts of accounts and central bank audits.
  • Performed quarterly and annual financial reporting, MIS.
Technologies: Visual Basic for Applications (VBA), SAP BusinessObjects Data Service (BODS), Oracle FLEXCUBE, Oracle 10g, Oracle, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, SQL, PL/SQL, Oracle RDBMS, SAP BusinessObjects (BO), Microsoft Data Transformation Services (now SSIS), Java, Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Windows, Architecture, Server Migration, Database Modeling, Data Architecture, Data-driven Design, Data Analysis, Data Analytics, Excel Macros, Data Visualization, Database Administration (DBA), Scalability, Relational Database Services (RDS), Data Management, Dashboards, Oracle PL/SQL, PL/SQL Tuning, Unix Shell Scripting, Excel 365, Data Integration, BI Reporting
2003 - 2008

Operations Supervisor

Intralot SA
  • Oversaw the adoption of new products (lotto, bingo, scratch tickets, and betting) from system operation, training, regulatory and market perspectives.
  • Supervised the technical operations for a local customer, Lottery of Macedonia.
  • Developed products supporting the operations and did tasks involving ETL, winnings calculation, crawling the competition's websites for offers, and risk assessment (e.g., Dutch Booking).
  • Performed operational requirements and sales/market analyses. Prepared financial reports.
Technologies: Visual Basic for Applications (VBA), Crystal Reports, Oracle9i, Oracle, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, SQL, PL/SQL, Oracle RDBMS, Microsoft Data Transformation Services (now SSIS), SQL Server Integration Services (SSIS), Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Windows, Architecture, Server Migration, Database Modeling, Data Architecture, Data-driven Design, Data Analysis, Data Analytics, Excel Macros, Database Administration (DBA), Scalability, Relational Database Services (RDS), Data Management, Oracle PL/SQL, PL/SQL Tuning, Unix Shell Scripting, Excel 365, Data Integration, BI Reporting
2001 - 2003

Senior Software Engineer

National Bank of Greece
  • Served as the technical lead behind the web-based loan application processing system (E-loans.nbg.gr).
  • Built a web service around the InTempo workflow engine and, for the client side, a single-page application that exchanged only data with the service. This set up reduced the network traffic and improved the app's response.
  • Developed a JavaScript library with functionalities similar to today's Angular/React. The library provided the means for the declarative definition of the data bindings and the definition of form components and templates for complex data structures.
  • Architected the solution that was accepted as genuinely simple to use and survived in operation for 15 more years when Internet Explorer was discontinued.
  • Developed ETL procedures for the foreign subsidiaries running GLOBUS (Temenos T24 predecessor).
  • Migrated older DBASE applications to the Microsoft platform (Microsoft SQL Server, Visual Basic, and DCOM).
Technologies: BPM, DTS, Database Transactions, SQL, ASP, JavaScript, Visual Basic 6 (VB6), Microsoft SQL Server, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, T-SQL (Transact-SQL), Visual Basic for Applications (VBA), Microsoft Data Transformation Services (now SSIS), SQL Server Integration Services (SSIS), Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Windows, Architecture, Server Migration, Database Modeling, Data Architecture, Data-driven Design, Data Analysis, Data Analytics, Database Administration (DBA), Scalability, APIs, Relational Database Services (RDS), Data Management, Oracle PL/SQL, PL/SQL Tuning, Unix Shell Scripting, Data Integration, BI Reporting
2000 - 2001

Software Engineer

Artisoft
  • Developed financial, inventory, CRM, HR, and other modules for an ERP system, "ART-AIIS".
  • Ported the business logic from an existing ColdFusion script to PL/SQL modules.
  • Ran a performance analysis and optimized time-consuming queries.
Technologies: Adobe ColdFusion, JavaScript, Crystal Reports, Oracle8i, Oracle, Data Warehouse Design, Data Warehousing, ETL, Data Pipelines, SQL, Visual Basic for Applications (VBA), PL/SQL, Oracle RDBMS, Microsoft Access, Data Modeling, Business Intelligence (BI), Databases, Windows, Architecture, Server Migration, Database Modeling, Data Architecture, Data-driven Design, Data Analysis, Data Analytics, eCommerce, Database Administration (DBA), Scalability, APIs, Relational Database Services (RDS), Oracle PL/SQL, PL/SQL Tuning, Unix Shell Scripting, Data Integration, BI Reporting
1999 - 2000

Software Engineer

Seavus
  • Created a messaging service that integrated the old paging system, email, and SMS. It was used to route SMS messages from a mobile phone to pagers or email.
  • Built a commercialized browser that was used for a rich in-store customer experience. It contained customized modules for interaction and communication.
  • Developed an Internet Explorer add-on for communication with a non-standard proxy server.
Technologies: Microsoft Visual C++, Visual Basic 6 (VB6), SQL, Microsoft Access, Windows, Architecture, eCommerce

Experience

Affectli

http://affectli.com
Over the years, I grew a passion for building a platform that enables users from different organizations to collaborate while keeping their data private.

The existing email ecosystem offers some great features. A private server, identification of the collaborating party (also from other organizations), a clear separation of the client and the server, i.e., a wide array of email clients, each able to connect to multiple accounts/email servers. It was lacking the user's profiles, sharing of data, communication (message/chat/call), and some basic BPMS for everyday interactions.

As a result, I led and architected the early development of the Affectli platform. Each of our customers hosts their Affectli instance just as they would an email server. Yet, their users can do much more. They share their data and start or participate in business processes within their organization or other organizations running Affectli.

The core platform functionalities can be extended through apps (client and server modules), packages of domain-specific BPMS, data schema, and UI forms/views. The apps keep the system modularized but also made a pathway for a marketplace ecosystem through third-party developers.

Analytics Module for an ML Project

I set up a data warehouse, including a denormalized schema, aggregations, and data partitioning.

The query execution times were improved dramatically, i.e., the same servers (CPU and memory) that used to support 30,000 documents now invested 100 million.

The existing API included an entry point for submitting documents directly processed/analyzed here. I implemented a data pipeline by de-coupling the processing steps into separate tasks. The implementation improved API response times with more straightforward, faster, and queued requests to the ML (Python) module.

Power BI Project (via Toptal)

I designed a data warehouse for reporting, implemented a REST API in Node.js to integrate with other third-party data sources, process data, and provide data-source endpoints for the PowerBI service. I also implemented a simple dashboard for system configuration and administration.

Within Power BI, I implemented the following:
• Reports and dashboards
• Data transformations using Power Query for modeling the report's data source
• DAX expressions in the report's UI
• Row-level security limiting data scope for different user roles
• Scheduling refreshing data and export of reports

I also modeled data to support the fast query execution needed for the dashboards (materialized views, aggregation, and so on).

BI Project (via Toptal)

I designed the data warehouse used for reporting, integrated with internal organization databases and other third-party data sources using Pentaho Kettle.
I then implemented reports and interactive dashboards in JasperReports. Lastly, I implemented aggregations, materialized views, and PL/SQL functions in the data warehouse used in integrations and fast query execution for reporting.

Skills

Languages

SQL, PL/pgSQL, JavaScript, T-SQL (Transact-SQL), Visual Basic for Applications (VBA), Snowflake, Python, Visual Basic 6 (VB6), Java

Frameworks

AngularJS, Express.js, Spark, Angular, Activiti BPM, ASP, Hadoop, Django

Libraries/APIs

JasperReports, Node.js, D3.js, pgRouting, OpenLayers, Google Maps API, Pandas, Socket.IO, Python API, ArcGIS

Tools

Crystal Reports, Oracle FLEXCUBE, Microsoft Power BI, Microsoft Access, BigQuery, Spark SQL, Apache Airflow, Tableau, Pentaho Data Integration (Kettle), DTS, Microsoft Visual C++, Adobe ColdFusion

Paradigms

ETL, Business Intelligence (BI), Data-driven Design, Spatial Databases, Data Science

Platforms

Oracle, Windows, Pentaho, Amazon Web Services (AWS), Java EE, Amazon EC2, Azure

Storage

Data Pipelines, Redshift, PostgreSQL, PostGIS, PL/SQL, Microsoft SQL Server, MySQL, Oracle RDBMS, GeoServer, Databases, Database Modeling, NoSQL, Database Administration (DBA), Oracle PL/SQL, Data Integration, SQL Server Integration Services (SSIS), Amazon Aurora, MongoDB, Oracle 10g, Oracle9i, Database Transactions, Amazon S3 (AWS S3)

Other

Data Engineering, Data Warehousing, Data Warehouse Design, SAP BusinessObjects (BO), Data Modeling, Architecture, Server Migration, Data Architecture, Data Analysis, Data Analytics, Excel Macros, Scalability, APIs, Relational Database Services (RDS), Data Management, Amazon RDS, API Integration, Dashboards, PL/SQL Tuning, Excel 365, BI Reporting, Microsoft Data Transformation Services (now SSIS), Data Visualization, Google BigQuery, TypeORM, TIBCO, SAP BusinessObjects Data Service (BODS), BPM, Oracle8i, Big Data, Data Quality, Software Engineering, eCommerce, Telemetry, IT Automation, Unix Shell Scripting, Data Build Tool (dbt), CI/CD Pipelines, QGIS

Education

1994 - 2000

Diploma (Bachelor of Science Degree) in Electrical Engineering, Computer Science, and Automation

Saints Cyril and Methodius University of Skopje - Skopje, Macedonia