Kaloyana Manova, Developer in Sofia, Bulgaria
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Kaloyana Manova

Verified Expert  in Engineering

Data Cleansing Developer

Sofia, Bulgaria
Toptal Member Since
June 18, 2020

Kaloyana has over a decade of experience building software solutions, including requirements analysis and functional specification, project planning, and system architecture design, full-stack development, database design and development, database administration, ETL, performance optimization, and general problem-solving. She possesses a strong attention to detail and great communication skills with all levels of business partners.


Independent Contract Work
PostgreSQL, MySQL, Microsoft SQL Server, Python, PHP
IKL (via Toptal)
Python, XML, SQL Server Integration Services (SSIS), Microsoft SQL Server
Motimatic (via Toptal)
Django, Periscope Data, Python, PostgreSQL




Preferred Environment

Linux, Windows

The most amazing...

...project I've designed and implemented is a custom built business intelligence solution for Philips’ worldwide market research analysis.

Work Experience

Freelance Software Architect | Full-stack Developer | Database Developer

2009 - PRESENT
Independent Contract Work
  • Consulted and assisted with software architecture, solution design, and database design on different projects and functionalities for different companies.
  • Worked on multiple web solutions—from requirements gathering and functional specification to solution architecture and development.
  • Implemented ETL processes, data cleansing, and data integration tasks.
  • Designed and implemented warehouse databases and reports.
  • Consulted on performance optimization, database tuning, and query optimization.
Technologies: PostgreSQL, MySQL, Microsoft SQL Server, Python, PHP

Freelance SQL Developer

2017 - 2018
IKL (via Toptal)
  • Created a maintenance plan for the existing databases.
  • Designed and implemented SQL scripts for questions generation from different knowledge bases.
  • Developed ETL routines for different data pipelines.
Technologies: Python, XML, SQL Server Integration Services (SSIS), Microsoft SQL Server

Freelance SQL Expert

2017 - 2018
Motimatic (via Toptal)
  • Worked closely with the data scientist to define and implement the reports required.
  • Implemented some ETL processes to optimize data storage for reporting needs.
  • Performed optimization and logic fixes on existing reports.
  • Created some monitoring routines to track inconsistency and/or missing of data.
Technologies: Django, Periscope Data, Python, PostgreSQL

Lead Database Developer | Administrator

2011 - 2016
USDirectory.com | Shooger.com
  • Performed gradually a major database redesign for Shooger.com—refined and improved existing databases routines resulting in a huge performance increase.
  • Took over the maintenance and further development of the databases used by USDirectory.com (a website the company purchased)—changed a lot of the regular data manipulation processes that were executing and added automation to increase work efficiency.
  • Designed, implemented, and supervised database changes, new database routines, and processes regarding new functionality.
  • Organized and maintained the administration of the databases in the company—security, backup, and disaster recovery processes, performance monitoring and troubleshooting, and more.
  • Implemented and maintained ETL processes, data integration, and data-cleansing routines.
  • Instituted a strict procedure of deploying database changes to test and production servers.
  • Undertook the creation of the documentation of the databases which involved database logic, hardware environment, installation and maintenance, disaster recovery planning, security, and more.
Technologies: ASP.NET Web Forms, C#, ASP.NET Web Services, SQL Server Reporting Services (SSRS), SQL Server Integration Services (SSIS), Microsoft SQL Server

Senior Software Developer

2009 - 2011
  • Designed and implemented the database and system architecture and lead the development of an e-ticket system for public administration uses.
  • Worked on improving the existing and designed and implemented new functionalities.
  • Performed database tuning and performance optimization for different projects.
  • Designed and implemented an algorithm for public transportation route finding which was used in the company’s web and mobile applications and also was integrated in Sofia Urban Mobility Center’s website. The work comprised of a database design, ETL, development of the web interface as well as the development of back-end administration module for the management of public transport data changes.
  • Created the initial version of the company’s Android application as well as the first version of the mobile website.
  • Contributed in recruiting and mentoring junior developers.
Technologies: jQuery, JavaScript, InterBase, MySQL, PHP

Senior Software Developer

2007 - 2009
Apis (Bulgaria)
  • Had a significant role in the creation of the web version of the company’s leading product—a legal and financial information system. Was deeply involved in the database design and implementation, the web development of both the products itself and the administration solution.
  • Developed with a database team a web information system covering companies and other entities registered in the national registry and related data.
  • Developed an internal CRM for the company.
  • Maintained the existing desktop projects, implemented a new functionality, and worked on performance optimization.
  • Was immersed in improving the usability, response time, and the overall users' perception of the product quality.
Technologies: JavaScript, MySQL, Microsoft SQL Server, PHP, Delphi

Quality Assurance Engineer

2006 - 2007
Apis (Bulgaria)
  • Established a solid testing process in the company.
  • Initiated the process of creating and keeping test documentation including quality assurance plans, test plans, and test cases both for existing and newly developed solutions.
  • Introduced a routine of defect retesting, regression testing, and destructive testing.
  • Implemented a usability analysis.
Technologies: Microsoft SQL Server, Delphi

Philips Heartbeat

I custom-built a business intelligence solution for Philips’ worldwide market research analysis—including a back-end system built to help with ETL, data cleansing, and integration, and a full-fledged web-based front-end reports visualization application.

Apis 7 Web

I developed a web solution that combines a legal information system, economic models, financial forms, computation algorithms, an information system on EU legislation and its relation to Bulgarian law, and an information module about the case law and the claim proceedings.

Live URL: http://web.apis.bg/

Ilina Ltd. Hybrid Business Application

I custom built a web-based application for Ilina Ltd. (Ilina.bg) and combined a CRM, a business process automation system, and a reporting functionality.


I developed a system for vehicle geo-tracking, providing real-time information to regulatory authorities about fuel deliveries and also providing logistics tools for the companies to be able to create, plan and assign daily tasks, and control their vehicles. The features report for both the companies and government reps.

Tix.bg | Public Transport Routes

I designed and developed an algorithm for finding directions with public transportation as well as its integration in with the site: Tix.bg.


I built a web-based application for real-time government control of warehouses storing products that are targets of excise taxation. It features generation of excise declarations, inventory logs, and other needed reports—and is used both by warehouse owners and regulatory authorities.


CSS, HTML, PHP, XML, SQL, T-SQL (Transact-SQL), JavaScript, C, Python, Delphi, C#


Periscope Data, Git, Confluence, Jira, Microsoft Word, Microsoft Excel, Microsoft Access, Subversion (SVN), Redmine


Requirements Analysis, Database Design, Waterfall Development, Scrum, Agile Software Development, ETL Implementation & Design


Database Administration (DBA), Data Integration, Microsoft SQL Server, ANSI SQL, Elasticsearch, MariaDB, SQL Server Reporting Services (SSRS), MySQL, SQL Server Integration Services (SSIS), PostgreSQL, InterBase, SQL Server Analysis Services (SSAS)


Performance Optimization, Data Cleansing, Regular Expressions, Full-stack, Algorithms, Software Architecture, Data Warehouse Design, Power Shell Commands


jQuery, Apache Lucene, Facebook Ads API, Twitter API


SharePoint, Linux, Windows, Apache Kafka, Heroku


ASP.NET Web Services, ASP.NET Web Forms, Windows PowerShell, Django

2014 - 2017

Masters's Degree (Dissertation Submission Pending) in Computer Technologies and Application Programming

Technical University, Sofia - Sofia, Bulgaria

2003 - 2009

Bachelor's Degree in Computer Systems and Technologies

Technical University, Sofia - Sofia, Bulgaria