Cosmin Rusu，瑞士洛桑的开发者
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Cosmin Rusu

Verified Expert  in Engineering

Full-stack Developer

Location
Lausanne, Switzerland
Toptal Member Since
December 6, 2017

Cosmin worked at Amazon, Google, 和苹果的高度可扩展性, distributed systems, 和专注于NLP的机器学习(Siri团队). He worked for a startup called Kuende, writing Scala and Go microservices on top of Google Cloud. Cosmin has a strong background in advanced algorithms and data structures in C/C++ and is very passionate about machine learning.

Full-stackWeb DevelopmentRubyGitHubC++LinuxStripe CheckoutReactRuby on Rails (RoR)Ruby on Rails 5JavaScriptPythonStripeStripe APIDockerSenior RubyOffshore PythonPySparkBraintreeELK StackSciPyAlgorithmScikit-LearnHugoJekyll

Portfolio

Abundance Digital
Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), Python, Full-stack, APIs, Linux...
Spotify - Main
React, Ruby, Ruby on Rails (RoR)，顺风CSS
Kindbody
Ruby on Rails (RoR)， Ruby on Rails API, HIPAA遵从性

Experience

Ruby - 6 yearsReact Native - 4 yearsRuby on Rails (RoR) - 4年React - 4 yearsJavaScript - 4 yearsScala - 4 yearsAzure - 2 yearsHIPAA电子数据交换(EDI) - 1年

Availability

Part-time

Preferred Environment

Ruby on Rails (RoR)，数据科学，Python, React, Scala, Git

The most amazing...

...thing I've coded was at my internship with Google where I delivered a new type of automatic content creation containing action moments from users' videos.

Work Experience

Stripe Data Consultant

2019 - 2023
Abundance Digital
  • Answered relevant business questions based on available Stripe data for this community-based company. The answers resembled their subscription model and how well it performs.
  • Implemented a checkout page allowing people to pay for the yearly subscription every month using Splitit.com.
  • Applied relevant SQL queries in Stripe Sigma so business owners can always run the queries on the latest data.
  • 帮助他们自动化与Zapier的登机流程.
  • Analyzed the subscription data and suggested ways to improve churn rate, revenue, and profit.
Technologies: Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), Python, Full-stack, APIs, Linux, Web Development, Ruby on Rails API, Ruby on Rails 5, Stripe API

React Developer

2021 - 2022
Spotify - Main
  • Migrated the front end of Megaphone (the podcast-ads business area of Spotify) to a modern stack with React. 使用当前标准重新设计他们的体系结构.
  • 重新设计了特性标志基础结构. 我们所有的新功能通常都在功能标志下发布, so they were an important piece that we needed to make sure we got right.
  • Built new components and added storybooks, unit tests, and end-to-end integration tests with Cypress. All new features were built using functional-style React with React Hooks.
  • Helped develop a strategy to upgrade our React version to the latest one.
技术:React, Ruby, Ruby on Rails (RoR)，顺风CSS

Senior Full-stack Engineer

2021 - 2022
Kindbody
  • Worked on an internal project for Kindbody to automate some internal billing processes using Ruby on Rails. 该应用程序使用了服务器端Rails模板, 但是对于更复杂的组件, 我们使用了在服务器上渲染的React组件(想想Next).js).
  • Tracked and implemented features via Trello and discussed with the CTOs and product managers.
  • Deployed the Rails application to the AWS Kubernetes service using Helm and Helmfile.
Technologies: Ruby on Rails (RoR)， Ruby on Rails API, HIPAA遵从性

全栈软件工程师

2019 - 2022
Mochila Fulfillment
  • 整合了外部货运标签提供商Shippo.
  • 为我们的日志基础设施部署了ELK堆栈.
  • 帮助团队自动化他们的任务并采用Jira.
  • 前端使用React，后端使用Scala和Java实现.
  • 对错误修复和各种新特性做出了贡献.
  • Migrated the whole infrastructure from DigitalOcean to Google Kubernetes Services (GKE). 使用Terraform自动提供基础设施. Used Helm, Helmfile, and Helm Secrets for secure deployment management.
Technologies: MySQL, Ansible, Rollbar, Bitbucket Pipelines, ELK (Elastic Stack), Docker, Apache Maven, React, Java, Scala, Full-stack, Google Kubernetes Engine (GKE), 谷歌云平台(GCP), Cloud, APIs, Linux, Web Development, DigitalOcean

首席高级软件工程师

2019 - 2020
Go4Ellis LLC
  • Led a team of two developers for this project that connects event operators with athletic trainers for sports events to help in case of any injuries.
  • Upgraded the whole system to the latest Stripe Billing and Stripe Connect API within the given deadline imposed by Stripe.
  • Implemented a HIPAA compliant module for a new feature that would allow users to record and store injury medical records.
  • 应用了一个CI/CD管道来快速交付Rails应用程序, 使用Fastlane和CodePush进行即时React Native更新.
  • Migrated the whole infrastructure from Heroku to AWS ECS and AWS RDS for Postgres.
  • Integrated and self-hosted Metabase—a full-stack open-source Business Intelligence tool.
  • Improved query times for a variety of API endpoints, fixed N+1 query issues.
  • Took part in the support rotation program, communicated, and fixed users' bugs. 使用Sentry处理生产问题，Zendesk处理支持票.
  • Deployed the back end to Azure Kubernetes Services and built a CI/CD pipeline to automate deployments.
Technologies: Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), 电子数据交换(EDI), Heroku, NGINX, Amazon S3 (AWS S3), Amazon弹性容器服务(Amazon ECS), React Native, React, Amazon Web Services (AWS), 电子病历(EMR), 电子健康记录(EHR), Healthcare, CTO, Architecture, Full-stack, APIs, Linux, Web Development, Ruby on Rails API, Ruby on Rails 5, Stripe API, Azure

全栈软件工程师

2019 - 2019
Testing Psych
  • Built the testingpsych.在不到三个月的时间里从零开始创建网站. The platform is a testing platform for medical students interested in practicing for their final exam.
  • Used Ruby on Rails 5.向客户解释所有的决定.
  • Kept the app very lean in terms of deployment (Heroku) and I was able to keep costs as a minimum while not sacrificing performance.
  • 通过使用哨兵捕获生产错误.
Technologies: Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), CSS, HTML, Bootstrap, React, Full-stack, APIs, Web Development, Ruby on Rails API, Ruby on Rails 5, Stripe API

前端软件工程师

2019 - 2019
SH Technology
  • Helped this property management early stage startup with their frontend app.
  • 使用Stripe的API实现SH Technology的支付流程.
  • Designed the web application for their different user type: admins, managers, owners, and tenants.
  • 通过前端和API工作的最佳实践指导团队.
Technologies: Stripe, HTML, CSS, JavaScript, React Native, React, APIs, Web Development, Ruby on Rails 5, Stripe API

Software Engineer Intern

2019 - 2019
Google
  • Researched new approaches to build a request predictor - a time-series discrete value model. 这个问题类似于间歇性需求预测. 考虑的方法包括克罗斯顿的方法, bootstrapping RNNs, and implementing and testing the performance of different algorithms on previously acquired data in Python Colab.
  • 实现了在我们的数据集中表现最好的方法.
  • 主动提出不同的方法使项目取得成功.
技术:c++、Python、云、计算机科学、Linux

Software Engineer Intern

2018 - 2018
Google
  • Built a fully automated machine learning model training and prediction pipeline. This was the first step in moving from alpha testing where we get the predictions manually by running R scripts, to a beta phase.
  • Ensured the data generated by the pipeline is consumed by an internal dashboard. A strong motivating factor for building an automated pipeline is that the data is always updated and will solve the out-of-sync data problem caused by communication delay between the Engineering, Product and Sales teams.
Technologies: Unix, Machine Learning, R, Protocol Buffers, C++, Cloud, APIs, Computer Science, Linux

Full-stack Developer

2018 - 2018
One Step Software
  • 作为一个清醒生活SaaS平台的全栈工程师.
  • Built the CI pipeline in order to make sure our service did not introduce any bugs.
  • Collaborated with the team to make our Trello better and advocated for a TDD approach in order to make sure we serve the best software to their clients.
  • 对Rails web应用程序做出了贡献, introducing new features, implement backlog tasks, and fixing existing bugs.
  • Developed the API for the React Native mobile app and then used that API to build the mobile app.
Technologies: Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), React Native, Heroku, Full-stack, Linux, Web Development, Ruby on Rails API, Ruby on Rails 5, Stripe API

Back-end Engineer

2017 - 2018
Kuende
  • Contributed to microservices for interacting with Google Cloud Storage and Google Cloud PubSub.
  • 开发了一个与Google Storage交互的GoLang gRPC服务器.
  • 构建了一个连接到Go服务器的Scala gRPC客户端. The reason for doing this is that Google Storage SDK does not currently support Scala.
  • Wrote unit, integration, and end-to-end tests for the Go and Scala microservices.
  • Dockerized and deployed each service to Google Kubernetes service using internal proprietary deployment tools.
Technologies: MySQL, Ruby, gRPC, Go, Scala, Google Kubernetes Engine (GKE), 谷歌云平台(GCP), Cloud, Web Development, Ruby on Rails API, Ruby on Rails 5

Full-stack Web Developer

2017 - 2017
NLV Production
  • Contributed to the implementation of new features and fixing bugs for the nlvproductions.com website.
  • Used Stripe as a payment processor and investigated the problems they were experiencing with customers being charged more.
  • Implemented a new workflow for the admin dashboard that improved the organization's processes.
  • Proactively provided multiple solutions for every problem that the customer was interested in solving.
  • 修复了我们在Heroku dyno上遇到的内存泄漏.
Technologies: Stripe, PostgreSQL, Ruby, Ruby on Rails (RoR), Mailgun, Sidekiq, Heroku, Full-stack, Amazon Web Services (AWS), APIs, Computer Science, Linux, Web Development, Ruby on Rails API, Ruby on Rails 5, Stripe API

Software Engineer Intern

2017 - 2017
Google
  • 在谷歌照片团队实习. The project involved extending the selection framework for auto-created movies based on user content and implementing a few new concept movies.
  • 创造了“儿童友好”电影的概念. The basic idea is that if we detect that a lot of pictures contain kids, toddlers, or children, 我们选择适合儿童电影的音乐.
  • Designed a second concept movie called 'Outdoor Movie' and it basically tries to match outdoor pictures with suitable outdoor songs.
  • Conceptualized a third movie called 'Highlight Reel' and the main idea is that we want to crop the user's videos so that we retain only some 'action moments'. An action moment is a 5s clip in the movie where we detect some action (i.e. (扔篮球或打棒球).
技术:协议缓冲区，Java 8

Mobile Developer

2016 - 2017
Kuende
  • Contributed to the team that develops the Kuende mobile application (available to download on AppStore and Play Store), 基于游戏化的社交网络.
  • 实现了一个基于Trie的搜索人的算法, 列表视图的包装器，以便您可以轻松声明, 向列表中添加过滤器和比较器, and other small features.
  • Optimized the way we persist our data so that the information is fast accessible and rendered on the phone.
  • Concepted and implemented the Flux architecture on top of C++ and Qt.
Technologies: iOS, Android, Flux, QML, Qt, C++, JavaScript, React Native, APIs, Web Development

Teacher

2016 - 2016
LearnHouse
  • Taught computer science fundamentals to high-school students through the non-profit organization (http://learnhouse.ro).
  • Presented advanced algorithms and data structures to students interested in the National Olympiad in Informatics.
  • You can find some of the problems that I solved on various competitive programming challenges can be found here: http://github.com/rusucosmin/cplusplus.
Technologies: Algorithms

Software Engineer Intern

2016 - 2016
Amazon
  • Interned in the Robot Detection Research Team at Amazon Development Center Iasi.
  • 创建了机器人属性的链接和评分系统. The main challenge was the huge amount of nodes and data that had to be processed every day.
  • Contributed to mitigation of all of the robotic activity that crawls our website, with two things in mind. 首先，我们不想屏蔽一个真正的用户! Second, we wanted to let some friendly bots crawl the website (eg GoogleBot, BingBot).
  • Designed a system that was able to give a score for each incoming request on the website. Then, based on that score we can decide if the current request was made by a human or a robot. For this approach, 我们将请求拆分为简单的属性，如用户代理, IP, customer id and we independently compute the scores for each such attributes. 最后，我们可以对分数进行平均，得到请求分数.
  • Computed the scores as a series of Hadoop Map Reduce jobs that ran on Amazon's Hadoop Clusters and infrastructure. I had a lot of freedom with the project and I learned a lot while designing such a scalable, distributed algorithm.
Technologies: Node.js, JavaScript, Machine Learning, MapReduce, Hadoop, Java, Amazon Web Services (AWS), Web Development

Android Developer

2013 - 2013
e-communio
  • Built the e-communio app based on the already built local church news website.
  • Understood the main concepts of Android OS and the process of publishing an app.
  • 创建应用程序作为一个非常简单的, and at the core, just a list view, containing the latest news that I parsed from a web service written in C# that connects to the database, gathers the news, and splits a JSON array.
  • On the mobile side, I created a request for the news, parsed them and displayed them. 当用户单击其中一个项目时, it will go to another screen where they could read the entire content of the article. There were other nice features such as increasing and decreasing the size of the text, sharing the article, 以及其他文本效果.
Technologies: Android

夏时制对用户影响的数据分析项目

http://github.com/alex-mocanu/Project
I've worked on a data analysis project to understand the impact of daylight saving time impact on web usage around the world.

Road Segmentation

致力于建立一个分类器来分割卫星图像中的道路.

Chatbot

使用Facebook Messenger代码的Facebook Messenger聊天机器人.

Scan a QR code in messenger and get different targeting ads/promotions.

API Integration

I have worked for NXT Spots Inc to integrate two of their services they were using: LeagueApps for their payment processor and Copper for their CMS.

Med Prep

I've built an online exam for medicine students web application for this client. 我使用的堆栈是Ruby on Rails, PostgreSQL, React.. js、ActiveAdmin和Stripe作为支付处理器.

管理仪表板显示聚合的事务数据.

流域数据可视化

http://epfl-dataviz.netlify.com/
I've created a visualization tool for people at Stanford to gain more insights into how different experiments affect watershed metrics.

Technologies: D3.js, jQuery, HTML, CSS, Bulma

巴贝斯-博雅大学克卢日-纳波卡课程

我在大学的所有项目作业.

那里的项目范围从web应用程序到机器学习, 并行和分布式编程, 甚至是数学课程，比如统计学或线性代数.

Timezone.email

I've built a Google Chrome extension that makes it easy to quickly convert date times intent in Gmail and Inbox by Gmail.

Languages

Ruby, C++, Java 8, JavaScript, Python, CSS, HTML, PHP, Scala, SQL, Java, QML, R, Go, Bash, GraphQL, Hugo, Elixir

Frameworks

React Native, Ruby on Rails (RoR)， Ruby on Rails 5, Lift, ASP.NET, gRPC, Qt, Spark, Flux, Bootstrap, Django, Flask, Hadoop, Phoenix, Tailwind CSS

Libraries/APIs

React, Ruby on Rails API, jQuery, Stripe, Stripe API, Stripe Connect API, Stripe Connect, D3.js, Facebook API, Facebook Messenger API, NumPy, Pandas, PySpark, Scikit-learn, Braintree API, Node.. js, Sidekiq, Rollbar, Vue, TensorFlow, Matplotlib, SciPy

Tools

Stripe Checkout, GitHub, Amazon弹性容器服务(Amazon ECS), NGINX, AWS密钥管理服务(KMS), Google Kubernetes Engine (GKE), Trello, IntelliJ IDEA, Jekyll, Git, Apache Maven, ELK (Elastic Stack), Ansible, Scikit-image

Paradigms

ETL, HIPAA Compliance, DevOps, Agile Software Development, Scrum, Data Science, MapReduce

Platforms

Docker, Linux, Kubernetes, 谷歌云平台(GCP), Jupyter Notebook, MacOS, Azure, Android, iOS, Heroku, Unix, Mailgun, Amazon Web Services (AWS), DigitalOcean

Other

Data Engineering, Architecture, Full-stack, Facebook, Web Development, Stripe Subscriptions, Algorithms, Data Structures, Algorithm Development, Security, 电子数据交换(EDI), Chrome Extensions, Cryptography, Applied Cryptography, CTO, 电子健康记录(EHR), 电子病历(EMR), APIs, Chatbots, BrainTree, Machine Learning, Protocol Buffers, Bitbucket Pipelines, Computer Science, Cloud, Leadership, Statistics, Data Analytics, Classifier Development

Industry Expertise

Healthcare

Storage

PostgreSQL, MySQL, Amazon S3 (AWS S3)， Google Cloud

2018 - 2020

数据科学硕士学位

EPFL | École Polytechnique Fédérale de Lausanne - Lausanne, Switzerland

2015 - 2018

计算机科学学士学位

博雅大学-克卢日-纳波卡

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