Evgeni Tsvetanov, Developer in Sofia, Bulgaria
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Evgeni Tsvetanov

Full-stack Developer

Sofia, Bulgaria

Toptal member since September 20, 2021

Bio

Evgeni is a full-stack developer and network engineer with a decade of experience. He has worked in ISP and mobile carrier enterprises and on products operating across the globe, such as the Facebook network, Cisco and other ISP networks, web security, and cryptocurrency. Evgeni's experience includes all technical aspects of software development and the systems behind well-functioning products, including the user interface, servers, network, cloud, algorithms, and architecture.

Portfolio

Madefor Solutions
Python, Apache Airflow, Pytest, Sentry, DevOps, PostgreSQL...
Facebook
Python 3, Go, Apache Thrift, Python, Scalability, Software Architecture...
Freelance
Node.js, Docker, SQL, Databases, Full-stack, APIs, Back-end Development...

Experience

  • TypeScript - 8 years
  • Python 3 - 7 years
  • PostgreSQL - 7 years
  • Networking - 5 years
  • JavaScript - 5 years
  • React - 4 years
  • MobX - 3 years
  • Docker - 2 years

Preferred Environment

MacOS, Linux, PyCharm

The most amazing...

...things I've worked on are a few systems that keep the network healthy in Facebook's data centers.

Work Experience

Lead Developer

2021 - 2026
Madefor Solutions
  • Established feature and technical design processes.
  • Led a small team of developers, provided guidance, and established work processes.
  • Designed the core system, including permissions system, dynamic labeling of records, dynamic database queries built from permissions and filters, dynamic validation, and more.
Technologies: Python, Apache Airflow, Pytest, Sentry, DevOps, PostgreSQL, Software Development Lifecycle (SDLC), FastAPI, Systems Design, Software Architecture, SQLAlchemy, Docker, Polars, React, MobX, TypeScript, Design Systems, Databases, Full-stack, APIs, Minimum Viable Product (MVP), API Integration, Back-end Development, OAuth, REST APIs, Data Engineering, GraphQL, GitHub, OAuth 2, API Development, TOTP, Redis, Claude Code, GitHub Actions, Full-stack Development, Performance Optimization, Amazon S3 (AWS S3), WebSockets, Artificial Intelligence (AI), Claude, Claude API, AI Integration

Production Network Engineer

2021 - 2021
Facebook
  • Assisted in developing a new workflow for a diagnostics tool that can be used manually or via API calls to report the health of circuits in the data center network.
  • Worked on a triaging and mitigation system that detects, correlates, and applies mitigation techniques on network issues.
  • Gained great insights into the design, provisioning, and operation of networks operating at an incredible scale across the globe.
Technologies: Python 3, Go, Apache Thrift, Python, Scalability, Software Architecture, Databases, Full-stack, APIs, API Integration, Back-end Development, REST APIs, Performance Optimization

Software Developer

2021 - 2021
Freelance
  • Developed a trading module and crypto exchange communication.
  • Built back-end services for creating and managing exchange orders.
  • Configured Docker deployment for a development environment.
Technologies: Node.js, Docker, SQL, Databases, Full-stack, APIs, Back-end Development, REST APIs, API Development, Redis, Full-stack Development, Performance Optimization, AWS Lambda, Expo, WebSockets, React Native

Senior Full-stack Developer

2016 - 2021
SoftServe
  • Developed a complex UI for a security testing platform to test vulnerabilities, including malware, viruses, protocol exploits, and zero-day attacks.
  • Built a healthcare application that provides a platform for healthcare manufacturers, suppliers, and hospitals to sell and purchase healthcare equipment.
  • Implemented the main message sequence exchange of several network protocols, including TLS, while following RFC specs. The protocol implementations were a part of a larger security testing tool.
Technologies: React, Python 3, MobX, Redux, Pyramid, Python, UI Development, User Interface (UI), Healthcare Supply Chains, Web Security, Transport Layer Security (TLS), Request for Comment (RFC), Network Protocols, NGINX, HTML, HTML5, CSS, Sass, Less, Full-stack, Web Development, Docker, REST, Next.js, Gulp, Webpack, Databases, APIs, API Integration, Back-end Development, Payment APIs, REST APIs, Selenium, Microservices, API Development, MongoDB, Django REST Framework, Full-stack Development, Performance Optimization, Amazon S3 (AWS S3), WebSockets, Azure

Network Engineer

2014 - 2015
A1
  • Co-created network designs for the core network of a mobile carrier and an ISP network in collaboration with a team.
  • Planned future expansions and changes in the network.
  • Managed the RIPE Local Internet Registry account and RIPE database objects and policies.
  • Worked on a software tool for provisioning and deploying network services across multiple network devices.
Technologies: Cisco Networking, JavaScript, Django, PostgreSQL, Cisco, Databases, Full-stack, APIs, Back-end Development, Payment APIs, REST APIs

Network Administrator

2012 - 2014
NET1
  • Developed CLI tools and scripts that automate everyday tasks, such as gathering and aggregating information from network devices.
  • Managed and administered core network devices in an ISP network.
  • Created designs for business virtual private networks.
Technologies: Networking, Juniper, Cisco, VPN

Experience

Back End for Crypto Trading Platform

https://www.cryptoview.com/
A cryptocurrency portfolio manager and multi-exchange trading platform. As a back-end Node.js developer, I integrated crypto exchanges and developed services to create and manage buy/sell exchange orders.

Web User Interface for a Security Testing Platform

A security testing platform for a variety of attack vectors, including network protocols, zero-day attacks, and malware. The UI offered various customization and configuration options with lots of wizards, dynamic views, interactive topologies, forms, and more. The platform also synced, transformed, and moved a lot of data between the web application and the back-end APIs.

I was the senior front-end developer for the project, and the application was built using React, MobX, and TypeScript as the base tech stack. We kept the interface performant and the development experience on the positive side.

Healthcare Equipment Platform

A healthcare platform that connects manufacturers of healthcare equipment with distributors and hospitals. I was a full-stack developer on the project. The back-end stack was built using Python, Pyramid, SQLAlchemy, and PostgreSQL, and we used TypeScript, React, and Redux for the user interface.

Certifications

FEBRUARY 2021 - FEBRUARY 2024

AWS Certified Developer - Associate

Amazon Web Services

OCTOBER 2019 - PRESENT

MongoDB Certified Developer, Associate Level (C100DEV)

MongoDB University

SEPTEMBER 2016 - PRESENT

Python 3.4

Brainbench

DECEMBER 2015 - DECEMBER 2018

Cisco Certified Network Professional (CCNP)

Cisco

MAY 2014 - MAY 2017

Service Provider Routing and Switching, Professional (JNCIP-SP)

Juniper

OCTOBER 2013 - MAY 2017

Service Provider Routing and Switching, Specialist (JNCIS-SP)

Juniper

SEPTEMBER 2013 - MAY 2017

JNCIA-Junos

Juniper

JULY 2013 - JULY 2016

Cisco Certified Network Associate (CCNA)

Cisco

Skills

Libraries/APIs

React, SQLAlchemy, REST APIs, API Development, MobX, Node.js, Claude API, RxJS

Tools

GitHub, Git, Claude Code, Claude, PyCharm, VPN, NGINX, Gulp, Webpack, Apache Airflow, Pytest, Sentry, Expo

Languages

Python 3, JavaScript, TypeScript, Python, SQL, GraphQL, Go, HTML, HTML5, CSS, Sass, Less

Frameworks

Django, Redux, OAuth 2, Django REST Framework, Pyramid, Apache Thrift, Next.js, Flask, Jinja, Selenium, React Native

Storage

PostgreSQL, MongoDB, Databases, Redis, Amazon S3 (AWS S3), NoSQL, MySQL

Paradigms

REST, Test-driven Development (TDD), DevOps, Microservices

Platforms

Docker, Amazon Web Services (AWS), AWS Lambda, MacOS, Linux, Azure

Other

Networking, Cisco Networking, Cisco, Full-stack, Front-end, FastAPI, APIs, Back-end Development, OAuth, Full-stack Development, Juniper, Design Systems, RESTFul APIs, Minimum Viable Product (MVP), API Integration, Payment APIs, GitHub Actions, Performance Optimization, WebSockets, AI Integration, UI Development, User Interface (UI), Healthcare Supply Chains, Web Security, Transport Layer Security (TLS), Request for Comment (RFC), Network Protocols, Web Development, Scalability, Software Architecture, Software Development Lifecycle (SDLC), Systems Design, Polars, Data Engineering, TOTP, Artificial Intelligence (AI)

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