Saša Šijak, Developer in Belgrade, Serbia
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Saša Šijak

Verified Expert  in Engineering

Full-stack Developer

Location
Belgrade, Serbia
Toptal Member Since
January 3, 2017

Saša拥有超过十年的专业软件工程经验. He also has strong analytical skills, a wide range of computer expertise, and a history of successful project outcomes. All in all, Saša is organized, attentive-to-details, 做事一丝不苟，主动主动，能够组织和优先处理多项任务，在压力下保持冷静和高效.

Full-stackJavaRedisSpringSpring BootReactWeb DevelopmentFront-endUser Interface (UI)CSSSQLApache MavenLinuxGitScrum

Portfolio

Pwnalot LLC
Next.js, Firebase, Web Analytics, React, styles -components, Stripe...
Toptal
DigitalOcean, PostgreSQL, Spring Boot, CSS, HTML, Docker, Cordova, MongoDB...
Geek (Sole Proprietorship)
CSS, HTML, Gradle, Kotlin, Spring, Java, Vue, Gatsby, GraphQL, React

Experience

Java - 9 yearsSoftware Architecture - 7 yearsFull-stack - 5 yearsSingle-page Applications (SPA) - 5 yearsJavaScript - 5 yearsSpring - 4 yearsGatsby - 3 yearsReact - 3 years

Availability

Part-time

Preferred Environment

Slack, Jenkins, YouTrack, Jira, Git, Linux, IntelliJ

The most amazing...

...我做过的一个项目是和一个团队合作，他们做了一个分布式搜索引擎，后来被Facebook收购了.

Work Experience

Full-stack Engineer

2020 - PRESENT
Pwnalot LLC
  • 开发了一个网站，出售用ChakraUI和Framer Motion制作的漂亮且响应迅速的UI块，并将代码导出到NextJS或GatsbyJS: http://reactui.boutique.
  • Created a website with a purpose of a digital will. Created switches, 多长时间对您进行一次服务检查?如果您不可用，它会向您发送预定义的消息. http://livemanswitch.com.
  • Handed all sides of the business: registration, taxes, marketing, sales, project implementation, and more.
Technologies: Next.js, Firebase, Web Analytics, React, styles -components, Stripe, Coinbase API, Mailgun, Twilio API, Mixpanel, Google Tag Manager, Facebook Pixel, Cloud Firestore, Firebase Web SDK

Freelance Full-stack Engineer

2017 - PRESENT
Toptal
  • 为最受欢迎的应用程序实现面向公众的网站，将教室与家长联系起来，并吸引孩子Classdojo: http://classdojo.com, http://ideas.classdojo.com, http://blog.classdojo.com.
  • 为一家最大的汽车制造商开发移动应用程序.
  • 在React/Gatsby中实现了一个网站，该网站在阿迪达斯的主页上得到了推荐，这是一个针对体育教练的大规模营销活动，教他们如何接近和保持女孩的运动(keepgirlsinsport).com).
  • 在一个团队中工作，创建了一个为教育设计的参与平台(Quadwrangle). My responsibilities were a front end in AngularJS, back-end API in Play framework, and creating Docker-based deployments.
  • 为木材加工领域的一家小企业从零开始实现了一个web应用程序. 以前，他们通过使用大型Excel表格和文件来组织和跟踪业务, shared through email and Dropbox.
  • 用GatsbyJS为一所学校建立了一个网站，并由无头CMS Contentful (http://www)支持.ecfs.org/en/).
Technologies: DigitalOcean, PostgreSQL, Spring Boot, CSS, HTML, Docker, Cordova, MongoDB, Linux, SQL, TypeScript, JavaScript, Vue, React, Kotlin, Java, Next.js, Gatsby, Contentful

Owner | Software Engineer

2016 - PRESENT
Geek (Sole Proprietorship)
  • Created the Hocudabudem.fit website from scratch using GatsbyJS, React, GraphQL, Netlify CMS, and hosted it on Netlify; also implemented the SEO and marketing campaigns.
  • 开发了一款多人多平台足球游戏.
  • 构建了一个多人回合制浏览器游戏，使用Vue实现.js and Firebase platform.
  • 创建了一个基于kotlin的开源启动模板.
技术:CSS, HTML, Gradle, Kotlin, Spring, Java, Vue, Gatsby, GraphQL, React

Software Engineer

2013 - 2019
Mozzart
  • 推动并领导了一个新的陆上赌场系统的实施，取代了传统的赌场系统，从而带来了新的商业机会和更好的架构. 在6个国家的700多家投注店使用.
  • Hacked a proprietary communication protocol for gambling machines on my own; after which we could make our own solution pushing out third parties, cutting on expenses, and opening the doors for exciting possibilities.
  • 实现了头奖动画和通知系统. 它取代了第三方解决方案，使我们能够更快地推出功能. 这个应用程序在每个赌场使用，它提高了利润，改善了玩家的体验.
  • 不断努力改进业务和制度——超越基本要求，突破旧企业制度和公司的边界. 提供了许多建议和解决方案，而不仅仅是技术问题.
  • 实现投注机/终端机项目，投注机放置在投注店或咖啡馆. It involved integrating several hardware products, make an API, deploy the system to several hundred machines, server and machine administration.
  • 实现了一个信息系统，允许我们的经理与玩家和客户互动, 它还会根据一些可配置的规则发送自动消息.
Technologies: CSS, HTML, Docker, Server Administration, Linux, Redis, ActiveMQ, Oracle, Spring, Vue, AngularJS, Java

Software Engineer

2017 - 2017
QuadWrangle
  • 为Quadwrangle(面向大学的互动平台)实现了新功能和支持旧功能.
  • Developed a new deployment system using Docker.
  • Integrated several different APIs.
Technologies: CSS, HTML, Cordova, Linux Administration, AngularJS, MongoDB, Docker, Play Framework, Java

Software Engineer | Team Lead

2012 - 2013
Alteatec
  • 为一个可扩展的高性能在线赌场系统设计后端架构.
  • 带领团队从零开始实现后端. 然后，各种客户和成千上万的玩家使用后端赚取巨额利润.
  • 执行各种游戏提供商，并与外部提供商进行沟通.
Technologies: Redis, Linux, ZeroMQ, MySQL, Python

Software Engineer

2008 - 2011
Wowd
  • 通过分析和优化Java虚拟机提高了应用程序的性能.
  • Created the first version of the Wowd iOS app.
  • Handled QA and testing.
Technologies: Linux, Java

Associate Lecturer

2009 - 2010
Union University, School of Computing
  • 为操作系统课程组织讲座.
  • 与学生一起在模拟器中实现各种操作系统部件-提高他们的理解和知识.
  • 在我任职期间获得了最好的学生评价之一.
Technologies: Operating Systems, Java

Software Test Engineer

2008 - 2008
Asseco
  • 为Asseco银行软件构建了一个定制的测试工具.
  • Designed and wrote various test cases.
  • 在大学组织了Asseco编程挑战赛.
Technologies: Microsoft SQL Server, C#

Classdojo Websites

http://classdojo.com
为最受欢迎的应用程序Classdojo实现高流量面向公众的网站，该应用程序将教室与家长联系起来，并吸引孩子参与.

该网站以前是用较旧的技术建立的，需要完全重写. 我已经实现了网站与React, GatsbyJS，和风格系统.

除了主要的网站之外，我还实现了其他面向公众的网站的想法.classdojo.com and blog.classdojo.com.

Website for Adidas

http://www.keepgirlsinsport.com
我在阿迪达斯的主页上建立了一个网站，这是一个针对体育教练的大力营销活动，目的是教他们如何接近和留住女孩.

As the sole developer, 我使用React/Gatsby构建了网站，并实现了自定义样式和设计.

Online Casino Management System

我设计并实现了在线赌场管理系统的后端. 这个系统后来在许多网站上使用，拥有成千上万的用户. 它非常灵活，并提供了一些竞争对手没有的关键功能. 它为客户创造了良好的利润，今天仍在许多网站上使用.

技术:Python, ZeroMQ, MySQL, SQLAlchemy, Redis, Linux

React UI Boutique

http://reactui.boutique
开发了一个网站，出售用ChakraUI和Framer Motion制作的漂亮且响应迅速的UI块，并将代码导出到NextJS或GatsbyJS.

构建了数百个随时可用的块和拖放构建器，以快速构建页面并预览它们.

我从零开始创建了它，从开发到营销，我包揽了一切, sales, deployments, and support.

Live Man Switch

http://livemanswitch.com
创建了一个网站，用于数字遗嘱的目的，并作为加密资产等数字资产的保护.

它是物理开关的数字版本，设计为在人类操作员丧失操作能力时激活或停用, such as through death, 失去意识或身体失去控制.

User can create switches, 并配置维修检查的频率, 通过哪个通道(电子邮件或短信)，如果它们不可用，则发送预定义的消息.

ECFS School Website

http://www.ecfs.org/en/
面向公众的网站，一个学校建设与GatsbyJS和无头CMS Contentful支持.

I did not build the site from scratch. 我在某个时候继承了这个项目，因为客户对以前的机构不满意，我现在是这个网站上唯一的开发者，已经有一年多了.

Land-based Casino Management System

我领导了一个陆地赌场管理系统的设计和实施，该系统在东南欧最大的博彩运营商中使用. 在几个国家，它被用来管理500多家博彩店和超过3家,000 gambling machines in real-time. 它被用来管理从机器信息到头奖和所有实时发生的事情. 这款游戏在伦敦ICE Totally Gaming fair上获得了巨大成功.

技术:Java, Spring Framework, AngularJS, Oracle Database, Redis, Linux, ActiveMQ

Customer Messaging System

I implemented a messaging system; this included both the back and front end along with an integration with the rest of the system. 这使我们的经理能够与玩家和客户进行互动. 当相关事件发生时，它还会自动向客户发送消息.

Technologies: Java, Spring, Vue.js, ActiveMQ, Oracle, Linux

Betting Machine and Terminal

我执行了投注机/终端项目的大部分内容. 这些机器放在投注店或咖啡馆里. 它涉及硬件审批流程, integrating several hardware products, 制作API并与系统的其余部分集成, 将系统部署到随机位置的数百台机器上, server and machine administration, and so on.

Technologies: Java, Spring, Vue.js, ActiveMQ, SQLite, Oracle, Linux

Jackpot System with Roulette

With a colleague, 我们在我们感兴趣的业务区域的陆地赌场中实施了首个与轮盘赌一起使用的累积奖金系统.

技术:Java, Spring, ActiveMQ, Oracle, Linux

Amazing Multiplayer Soccer Game

我与一个团队合作创造了一款多人回合制足球游戏，吸引了成千上万的玩家和投资者.

Technologies: Java, JavaScript, Vert.x

Hacked Proprietery Protocol

我破解了赌博机通信的专有协议通过修改串行电缆和流量分析来嗅探流量. 后来，我编写了实现该协议的服务器，并在今天成功地使用.

Hocudabudem.fit | Online Presence

http://hocudabudem.fit
I set up the website, Facebook page, Instagram account, the brand's whole online presence, 私人教练业务的搜索引擎优化和营销活动. At first, 这个网站是用WordPress创建的，因为截止日期压力很大，后来我用GatsbyJS(一种基于React和graphql的静态网站生成器)重写了它，并把它托管在netflix上. 网站还有一个受保护的部分，使用Firebase认证和Firestore.

技术:React, GatsbyJS, Firebase, WordPress, Contentful, netflix

Flat (Apartment) Ad Scraper

我需要找一套公寓出租，而网上90%的广告都来自糟糕的中介机构——我花了一个月的时间试图手动找到一套公寓.

To solve this, 我编写了一个程序，每隔几个小时就用平面广告抓取网站, filters out all the agency and fishy ads, 并向我展示了城市中所有我感兴趣的好地方和其他参数.

In the end, I found a flat in one day. 两年后我又用了这个程序，结果还是一样——我也在一天内找到了一套公寓. Then I decided to share it with friends.

Technologies: Java

Fun Factory Apps on Android

我在谷歌Play上测试了各种盈利方法。, marketing strategies, and app positioning in the search results. 由于应用的技术，该应用程序每小时获得非常好的美元回报.

Technologies: Java, Android

Languages

Java, HTML, SQL, JavaScript, CSS, Sass, YAML, c#， HTML5, Python, TypeScript, Kotlin, GraphQL

Frameworks

Spring, Spring Boot, Spring 5, Tailwind CSS, Next.. js, JPA, Play Framework, Flask, AngularJS, Bootstrap, Ktor, Redux

Libraries/APIs

React, Vue, Vuex, MobX, ZeroMQ, Stripe, Coinbase API, Twilio API, Firebase Web SDK, Socket.IO, JOOQ, SQLAlchemy，谷歌云API，情感库，谷歌地图，谷歌地理编码API

Tools

JetBrains, Terminal, Slack, Git, ActiveMQ, Apache Maven, IntelliJ, Facebook Pixel, Google Analytics, MailerLite, Figma, Docker Hub, Vagrant, YouTrack, Jenkins, Subversion (SVN), Gradle, PostCSS, JSX

Platforms

Netlify, Linux, Contentful, Oracle, DigitalOcean, Mailgun, Mixpanel, Algolia, Firebase, Kubernetes, Docker, Amazon EC2, Amazon Web Services (AWS)

Storage

Redis, H2, PostgreSQL, Cloud Firestore, Firebase Realtime Database, Spring Data, Microsoft SQL Server, Google Cloud, Memcached, Oracle 12c, MySQL, MongoDB, MySQL/MariaDB

Other

Single-page Applications (SPA), Full-stack, Web App Deployment, Creative Problem Solving, Software Design, Gatsby, Front-end, User Interface (UI), Casinos & Gaming, APIs, Software Architecture, Server Administration, Web Development, Browsers, Data Structures, Operating Systems, Linux Administration, Cordova, Web Analytics, Google Tag Manager, Design Systems, Chakra UI, Framer Motion, Vercel, Message Queues, Analytics, Administration, Cloud, Styled-components

Paradigms

Scrum, Design Patterns, REST, Service-oriented Architecture (SOA), Object-oriented Programming (OOP), Continuous Integration (CI), DevOps, Test-driven Development (TDD), Functional Programming, On-page SEO, Testing, Hosting

2006 - 2010

Bachelor's Degree in Computer Science

联合大学计算机学院-贝尔格莱德，塞尔维亚

NOVEMBER 2019 - NOVEMBER 2021

Google Associate Cloud Engineer

Google