freiberufler Web3, Backend, Blockchain (Go, Solidity, NodeJS, PHP, Ethereum, Avalanche), FinTech + eCommerce. Keywords: Go, Solidity, Dart, Polygon, PHP, Symfony, PostgreSQL, MySql, Sylius auf freelance.de

Web3, Backend, Blockchain (Go, Solidity, NodeJS, PHP, Ethereum, Avalanche), FinTech + eCommerce. Keywords: Go, Solidity, Dart,...

zuletzt online vor 3 Tagen
  • auf Anfrage
  • 14167 Berlin
  • Europa
  • de  |  en
  • 19.08.2023

Kurzvorstellung

Web3-Applications, SmartContracts for Ethereum + Avalanche + Polygon, Scalable and reliable Backends with Go + PHP, SubNets for Avalanche, TypeScript, familiar with the following Frameworks: OpenZeppelin, ethersjs, Hardhat, NestJS, Symfony, Sylius

Qualifikationen

  • Android Entwicklung
  • Blockchain (allg.)
  • Datenbankentwicklung
  • Ethereum
  • Flutter
  • Go (GoLang)
  • Go (Programmiersprache)
  • GraphQL
  • iOS
  • Java (allg.)
  • JavaScript
  • mySQL
  • Node.js
  • Objective-C
  • PHP
  • PostgreSQL
  • React Native
  • Software Architektur / Modellierung
  • Software engineering / -technik
  • Softwareentwicklung (allg.)
  • Solidity
  • Symfony (Framework)

Projekt‐ & Berufserfahrung

SmartContracts für Elektronische Wertpapiere auf Ethereum gemäss eWpG
Chartered Investment AG, Berlin
12/2021 – 11/2022 (1 Jahr)
Finanzdienstleister
Tätigkeitszeitraum

12/2021 – 11/2022

Tätigkeitsbeschreibung

SmartContracts sowie notwendige Web-Applikationen für ein gemäss dem elektronischen Wertpapierregistergesetz entwickelten digitalen Wertpapier auf der Ethereum Blockchain sowie der Avalanche Blockchain

- OpenZeppelin
- Hardhat
- VueJS / Quasar
- NodeJS für Registerauszug

Eingesetzte Qualifikationen

Application Development, Back-End Entwicklung, Blockchain (allg.)

Blockchain Developer (SmartContracts, dApps, Backend)
TokenForge GmbH, Berlin
6/2021 – offen (2 Jahre, 10 Monate)
IT & Entwicklung
Tätigkeitszeitraum

6/2021 – offen

Tätigkeitsbeschreibung

CTO und Lead-Developer for Blockchain-Applications:_
- Security Tokens
- eWpG-Registry-Software
- dApps
- NFTs,
- Token-Issuance
- SmartContracts (ERC20, ERC721, ERC1155, ERC2771, ERC1400)
- Backend (Go, NodeJS, PHP)
- AWS
- Kubernetes / DevOps

Eingesetzte Qualifikationen

Blockchain (allg.), Datenbankentwicklung, Go (GoLang), GraphQL, mySQL, Node.js, PHP, PostgreSQL, Software Architektur / Modellierung, Software engineering / -technik, Solidity

Interims-CTO / Chief of Backend Development
Kundenname anonymisiert, Berlin
1/2020 – 12/2020 (1 Jahr)
Finanzdienstleister
Tätigkeitszeitraum

1/2020 – 12/2020

Tätigkeitsbeschreibung

For an API-based Payment Gateway including Bank Account Openings, Multi-Wallet-Transactions, Bankwire PayIns + PayOuts, Creditcard-Payment, 3DS, PSD2 compatibility, I was developing the Software-Architecture and did Backend-Development.

Technology Stack:
- Go
- Postgres SQL
- nats.io
- Kubernetes
- Traeffik
- Ingress
- KeyCloak / OAuth2 / OpenID
- Prometheus
- GrayLog
- Grafana

Eingesetzte Qualifikationen

Go (Programmiersprache), PostgreSQL

Interims-CTO, SmartContracts, App-Development and Backend
Yair GmbH, Berlin
6/2018 – 12/2019 (1 Jahr, 7 Monate)
Medienbranche
Tätigkeitszeitraum

6/2018 – 12/2019

Tätigkeitsbeschreibung

SmartContracts on Ethereum, Aeternity and EOS. Token-Sale-Platform (Symfony/Sylius/PHP+MySql), Crossplatform-App-Development with Flutter, Backend and REST-API with Symfony/PHP

Eingesetzte Qualifikationen

Blockchain (allg.), EOS.IO, Flutter, mySQL, Symfony (Framework)

Token-Sale-Platform and Smartcontracts on ERC20-Basis (Ethereum)
Cleyond AG, Starnberg
1/2018 – 10/2018 (10 Monate)
Chemieindustrie
Tätigkeitszeitraum

1/2018 – 10/2018

Tätigkeitsbeschreibung

Smart-Contracts mit Solidity auf Basis von Ethereum, ERC 721-TokenContract, Vesting Contract, Token-Sale-Platform auf Basis von Symfony/Sylius (PHP) und MySql als Datenbank.

Eingesetzte Qualifikationen

Blockchain (allg.), Solidity, Symfony (Framework)

Crossplatform App-Entwicklung mit React-Native
Cooblr GmbH, München
1/2017 – 12/2017 (1 Jahr)
Dienstleistungsbranche
Tätigkeitszeitraum

1/2017 – 12/2017

Tätigkeitsbeschreibung

Crossplatform App-Development with React-Native and native libraries both for iOS (Objective-C) and Android (Java).
Backend-Development with Loopback (NodeJS-Library) and MongoDB as backend database

Eingesetzte Qualifikationen

Java (allg.), Objective-C, React Native

Crossplatform App-Development with ReactNative
ENERGETIX GmbH & CO. KG, Remote
7/2016 – offen (7 Jahre, 9 Monate)
Handel
Tätigkeitszeitraum

7/2016 – offen

Tätigkeitsbeschreibung

Crossplatform-App-Development with React-Native. As an ongoing project, from time to time I do further development and/or maintenance like ReactNative-upgrades, bug fixing and developing new features

Eingesetzte Qualifikationen

Java (allg.), Objective-C, JavaScript, React Native

Interims-CTO, App- und Webentwicklung Zizzle eLearning Inc.
Zizzle eLearning Inc., Salt Lake City, USA, München, Salt Lake City
4/2016 – offen (8 Jahre)
Medienbranche
Tätigkeitszeitraum

4/2016 – offen

Tätigkeitsbeschreibung

Backend und REST-API für Content-Verwaltung auf Basis von Symfony/Sylius (PHP), App-Entwicklung mit React-Native, native Libraries für DMS und Encryption für iOS und Android

Eingesetzte Qualifikationen

mySQL, iOS, Software Architektur / Modellierung, Android Entwicklung, Java (allg.), Objective-C, Softwareentwicklung (allg.), JavaScript, PHP, React Native, Symfony (Framework)

Lead Developer
www.[...].de, München
5/2015 – 2/2016 (10 Monate)
Medienbranche
Tätigkeitszeitraum

5/2015 – 2/2016

Tätigkeitsbeschreibung

With a small team the web portal -Hyperlink entfernt-.[...].de has been build and published under my direction. The portal is germanys biggest directory of local farmer shops and gives them visibility in the internet. I developed the backend of [...] as well as the native iOS-App.

The core system of the portal is also used as a white-label solution with multi-client capabilities from other companies and drives several industry portals in the DACH-region.

My technical competencies:

- Symfony 2
- MySql 5.6
- PHP 5.4-5.6, Javascript, LESS
- Composer, Puppet, Vagrant, Grunt, Bower, NPM
- geographical circumcircle search
- dealing with APIs from Google, Geonames, Facebook, Twitter, Factual and many more
- SEO optimization
- high performance web application / high performance database
- AWS-Components: S3, EC2 and Cloudfront
- Cloudinary
- native iOS Apps

Eingesetzte Qualifikationen

mySQL, Symfony (Framework), PHP

Project Lead Developer
Yatego GmbH, München
4/2013 – 12/2015 (2 Jahre, 9 Monate)
eCommerce
Tätigkeitszeitraum

4/2013 – 12/2015

Tätigkeitsbeschreibung

In the first 2 years I was part of the refactoring team where the whole software stack of [...]  eCommerce platform -Hyperlink entfernt- has been rebuild. The main goal was to create a high reliable and high performance eCommerce platform for this large german marketplace, which has been achieved successfully.

2014 we started a new project called [...] (-Hyperlink entfernt-), building everything from scratch with modern technologies and agile methodologies.

My technical responsibilities for [...] are the native iOS-part of the app development as well the backend of the platform including various APIs (e.g. Facebook API and Cloudinary). I also built the social media integration and supported the developer team in all topics.

Technical specialties:
- PHP 5.5, JavaScript
- Objective-C
- Javascript
- Test Driven Development (very high coverage)
- MySQL (Percona) 5.6, Liquibase
- ElasticSearch
- Symfony 2, PHPUnit, Bootstrap, Kiwi
- Node, npm, Bower, Composer, Grunt
- Vagrant, Puppet
- Facebook SDK
- Factual SDK
- Cloudinary
- Google Places API
- Titanium AppCelerator
- Kiwi (TDD for native iOS Apps written in Objective-C)
- JasmineJS

Eingesetzte Qualifikationen

mySQL, iOS, Agile Entwicklung, Objective-C, Mobile Entwicklung (allg.), iOS Entwicklung, PHP, JavaScript, E-Commerce

Software Developer
Amakura GmbH, Köln
5/2011 – 3/2013 (1 Jahr, 11 Monate)
Versicherungen
Tätigkeitszeitraum

5/2011 – 3/2013

Tätigkeitsbeschreibung

With a team of 6 developers we built a web-based ERP software for the insurance sector. Besides the integration of finance-related interfaces and data imports like MT940 and DTAUS, I was responsible for performance optimizations, for both frontend and backend, particularly the Microsoft SQL Server database.

Technical skills:

- C# / ASP.NET
- Javascript, Coffeescript
- Microsoft SQL Server

Eingesetzte Qualifikationen

Transact-SQL (T-SQL), Microsoft SQL-Server (MS SQL), C#, ASP.NET, JavaScript

Backend-Developer
medolan UG, Meerbusch
1/2011 – 1/2012 (1 Jahr, 1 Monat)
Gesundheitswesen
Tätigkeitszeitraum

1/2011 – 1/2012

Tätigkeitsbeschreibung

As the leading software developer for this eHealth Startup based in Düsseldorf (Germany) I was responsible for the development of the whole software stack.

The software stack can be summarized with the following components:
- database (MySql)
- backend (PHP)
- frontend (JavaScript, HTML)
- APIs
- data imports/-exports
- Apps
- Testdriven development for both backend and frontend

Eingesetzte Qualifikationen

mySQL, PHP

Software Developer
Chronocycle Solutions GmbH, Düsseldorf
11/2008 – 4/2011 (2 Jahre, 6 Monate)
Versicherungen
Tätigkeitszeitraum

11/2008 – 4/2011

Tätigkeitsbeschreibung

C#, ASP.NET, MS SQL Server

Eingesetzte Qualifikationen

Microsoft SQL-Server (MS SQL), C#, ASP.NET

Software Developer
Sedo GmbH, Köln
2/2006 – 10/2008 (2 Jahre, 9 Monate)
Medienbranche
Tätigkeitszeitraum

2/2006 – 10/2008

Tätigkeitsbeschreibung

I was member of the web application development team and amongst other things responsible for the development of the real time auction system and several backend tools.

Web Application-, Libraries- & Database Development (LAMP)
Linux, Apache, MySQL, PHP

Eingesetzte Qualifikationen

Datenbankadministration, JavaScript, jQuery, mySQL, PHP

Software-Engineer
LECTOR Computersysteme GmbH, Mönchengladbach
8/1998 – 1/2006 (7 Jahre, 6 Monate)
IT & Entwicklung
Tätigkeitszeitraum

8/1998 – 1/2006

Tätigkeitsbeschreibung

Software-Engineer (Windows-Application, C++, .NET-Framework, MS-SQL-Server, Web-Applications with ASP.NET)

Eingesetzte Qualifikationen

.Net Framework (Microsoft), C#, C++, Microsoft SQL-Server (MS SQL)

Freelance Engineering
multiple, Berlin
1/1996 – 6/1998 (2 Jahre, 6 Monate)
IT & Entwicklung
Tätigkeitszeitraum

1/1996 – 6/1998

Tätigkeitsbeschreibung

Freelancer as Software-Developer (Pascal, Delphi, C++) for multiple Clients.

I developed a "Duty Roaster" software for hospitals and build tools and apps around this topic.

Eingesetzte Qualifikationen

C, Delphi

Über mich

Since 1990 I'm developing desktop-applications, web-applications, mobile apps, libraries & interfaces in Linux, Mac and Windows environments and (since 2017) Smart Contracts on Ethereum for various industries. As a senior software developer and founder, both alone and as a member of a founding team, I gained strong skills in finance markets, eCommerce and deep startup experience.

My main area of interest in the last 10 years was and is to build fast, high scalable and high reliable web applications including strong Backends. Also since 2012 I have been building many apps (mostly native iOS), e.g. health apps, a chat app for a social network with a geospatial search, apps for local business search, apps for internal customer tools and many more. Since 2017 many blockchain based projects came into my life, both from frontend and backend perspective. In recent 4 years I spent my days in FinTech and Investment firms with both, regular money and blockchain based payments.

Weitere Kenntnisse

Technical Blockchain Experience since 2017 with Ethereum and BitCoin; From software development perspective, my core competencies are: Go, PHP, Dart/Flutter, Objective-C, C++, C#, PostgreSQL, MySQL, TypeScript, Symfony, AWS, React Native, Cloudfront, Cloudinary, Linux, Building fast and reliable Web Applications, Unittesting (PHPUnit, QUnit, CasperJS, Kiwi, Jasmine), Apache, OOA,OOD,OOP, ReactiveCocoa, Restful Web Services (REST), Performance Optimization

Persönliche Daten

Sprache
  • Deutsch (Muttersprache)
  • Englisch (Fließend)
Reisebereitschaft
Europa
Arbeitserlaubnis
  • Europäische Union
Home-Office
bevorzugt
Profilaufrufe
3974
Alter
48
Berufserfahrung
34 Jahre und 2 Monate (seit 01/1990)
Projektleitung
7 Jahre

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