Josef Zamrzla

Josef Zamrzla

Web and mobile applications developer

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About me

I am a software developer specializing in the development of web applications and distributed systems, primarily in JavaScript (Node.js, React). I have over 20 years of experience in designing and implementing demanding solutions – from high-load systems to modern web applications.

Thanks to a deep understanding of both backend and frontend technologies, I offer the ability to design and deliver an entire product – from architecture, data model, and API to the final user interface. A good example is the Skilleto job portal, which I architected and designed, developed, launched, and continue to operate.

Technologies and Tools

  • Languages and Frameworks: JavaScript (Typescript, CoffeeScript), Python, Bash, HTML, CSS/SCSS
  • Frontend: React, Redux, Zustand, MobX
  • Backend & Messaging: Node.js, REST API, RabbitMQ, WebSockets, WebRTC
  • Databases: PostgreSQL, Redis, MongoDB, Elasticsearch
  • DevOps & Infrastructure: Docker, CI/CD, Jenkins, Ansible
  • Architecture: Design of distributed and microservice systems, scalability, fault tolerance

Contacts

Email: josef.zamrzla@gmail.com Mobile: +420 605 925 361 Website: https://www.zamrzla.eu

Recent projects

Skilleto.cz - a smart job portal

www.skilleto.cz

Design, architecture, and development of a smart job portal leveraging AI features. Own project.

Technology: Node.js, PostgreSQL, Elasticsearch, RabbitMQ, Redis, React, Redux, websockets, HTML, CSS/SCSS

MONETA Money bank

www.moneta.cz

Portal applications development, online banking development.

Technology: React (Typescript), Redux, HTML, CSS/SCSS

Deutsche Böerse Group

www.deutsche-boerse.com

Development of web applications for managing stock market portfolios.

Technology: React (Typescript), Redux, Zustand, NX, HTML, CSS/SCSS

xyndata

www.xyndata.com

Video conference platform architecture and development.

Technology: Node.js, PostgreSQL, Elasticsearch, RabbitMQ, React, Redux, WebRTC

GoEuro

www.goeuro.com

Fullstack web applications development.

Technology: Node.js, React, Redux, MobX

Novartis

www.novartis.com

Internal web (intranet) applications development (fullstack).

Technology: Node.js, MySQL, Angular (Typescript), React/Redux, MongoDB

Socialbakers

www.socialbakers.com

Development of payment gateway application that accepts both one-off and recurring payments via Recurly application. Communication with Recurly API and Salesforce API.

Technology: Node.js (Coffeescript), React, MongoDB, Redis, PostgreSQL, RabbitMQ

Develoment of distributed application for analysis and content publication on social networks. Profiling of Node.js apps, solving problems with high CPU and memory consumption of Node.js apps, detecting and managing memory leaks, garbage collection optimalizations.

Technology: Node.js (Coffeescript, ES6), Elasticsearch, MongoDB, Redis, PostgreSQL, RabbitMQ, Websockets

Angelcam (Click2stream)

www.angelcam.com

Design and development of high scalable, fault tolerant, service oriented platform for live video streaming from surveillance cameras. Development od docekerized microservices with service discovery option. Profiling of Node.js apps, solving problems with hign CPU and memory consumption of Node.js apps, detecting and managing memory leaks, garbage collection optimalizations.

Technology: Node.js, Redis, Docker, Consul.io, Ansible, bash

Low-level MJPEG video stream parser and proxy application.

Technology: Node.js, Redis, Docker, bash

AdInternet

www.adinternet.cz

CRM system development for lead-management in real-estate. Microsites generator. Automated pricelist parser including unstructured format parsing from web crawler.

Technology: Python (Django framework), PostgreSQL, MySQL

Work experience

Software Development Engineer - Skype (3/2013 – 10/2013)

REST API development, work in environment of massively scaled (sharded) PostgreSQL databases.

Technology: PHP, Python, PostgreSql (PL/pgSQL, PgBouncer, PL/proxy)

Application developer - LMC s.r.o. (10/2011 – 2/2013)

Web applications development for biggest czech job portal Jobs.cz

Technology: PHP, Javascript (AngularJS), XSLT, CouchDB, PostgreSQL, ActiveMQ, Fast ESP

PHP developer, software development manager - Internet retail a.s. (10/2005 – 9/2011)

Web applications development for a network of e-shops (Kasa.cz, Hej.sk, Eurocomm.de, Eurocomm.pl). Backoffice apps, inventory management apps, automatic price management, automated communication with external suplliers.

Leading a team of developers.

Technology: PHP, MySQL