Mike Szyndel
Verified Expert in Engineering
Software Developer
Berlin, Germany
Toptal member since June 28, 2017
Mike is a seasoned full-stack developer and software architect with in-depth knowledge of Node.js, Ruby on Rails, and React. He has a unique ability of understanding and translating business requirements into development roadmaps. In his previous roles as a team lead and CTO, he has developed strong project management and communication skills.
Portfolio
Experience
Availability
Preferred Environment
Atom, MacOS
The most amazing...
...thing I've built was a distributed scraper which continuously indexed all YouTube channels.
Work Experience
Senior Software Developer
Shopify
- Scaled a centralized package tracking system to process 160 million shipments and 2+ billion status updates per month.
- Collaborated with external partners, such as UPS, DHL, and Parcel Perform, designing and building state-of-the-art integrations. This work led to much higher throughput, lower latencies, and cost savings of $500,000 per year.
- Mentored junior engineers through pair programming and code reviews, involving them in higher-level technical design work and department-wide show and tells. Helped build promotion case from an intern to the developer, skipping the junior level.
Senior Software Engineer
Fortune 500 Manufacturing Company
- Created a library of reusable React components, including documented use cases in Storybooks and tests in Jest/Enzyme.
- Implemented ARIA landmark 1 accessibility requirements.
- Upgraded an existing data API service from Rails 4 to Rails 6.
- Implemented new data API endpoints, focusing on speed, caching, and data structure tailored for the presentation layer.
- Migrated legacy local websites into a single multilingual site.
- Lowered the cost of feature development, improved delivery times, largely removed QA issues on new pages, and improved site performance.
Senior Software Engineer
Prodigy Finance
- Prepared architectural outline and led implementation of an OAuth OpenID Connect provider, enabling single-sign-on (SSO) to all Prodigy services.
- Migrated existing services from EC2 to ECS Fargate, enabling autoscaling, blue-green deploys, and improving security.
- Reimplemented existing Excel cash flow models as a Ruby on Rails and React application, lowering turnaround time for new models from days to minutes.
Project Leader
Market Research Company
- Gathered business requirements and provided timeline and technical architecture of the project.
- Built a distributed, queue-based, horizontally scaling scraper in Node.js, deployed to ECS.
- Integrated residential IP address proxy and CAPTCHA solving service.
- Implemented the ETL process, ingesting data from Alibaba, AliExpress, Taobao, and Tmall.
- Built the React front end, allowing data filtering, data export, and scraping progress monitoring.
CTO
Stagelink
- Developed a tool indexing more than 30 million unique YouTube channels weekly, using a mix of API access and scraping.
- Rebuilt a legacy jQuery front end in React from scratch for both Stagelink customer-facing products; moved away from a monolithic Rails app towards API-based services.
- Implemented and optimized a show-attendance prediction algorithm designed by the company's CEO. Deployed the new code to production—increasing prediction accuracy by 15% and increasing the calculation speed three-fold.
- Hired and led a team of six developers—performing code reviews and training sessions, having one-on-one meetings every two weeks, and mentoring junior developers.
- Designed a voting fraud detection system that analyzed tens of thousands of votes per day to identify fake users, multiple votes by the same person, and other abuses.
- Implemented an extensible payment back end, interfacing with multiple payment providers, including PAYMILL, Stripe, PayPal, SOFORT, and Wirecard.
Software Engineer
Digital Polsat
- Developed a search engine for a music-streaming platform consisting of more than 15 million songs. The search engine was based on Elasticsearch and MongoDB and was deployed to a cluster of EC2 servers.
- Finetuned a search engine configuration based on artist popularity and measurements of hit/miss ratio for presented results.
- Exposed the search engine to mobile, web, and desktop applications by building a JSON-based API service in Rails.
- Implemented a recommendation service based on user preferences, content team picks, etc.
- Developed a caching-layer based on Memcached (for in-app caching) and Varnish (for page and endpoint-level caching).
Full-stack Developer
LiveChat
- Integrated LiveChat with various third-party applications including Zendesk, Salesforce, Highrise, and Zoho to pull customer data into a chat window.
- Built an outside-facing REST API, wrote docs and sample code, helped outside developers integrate with it, and troubleshot issues.
- Created chat plugins for popular eCommerce solutions (Shopify, Magento, WooCommerce, and the like).
- Developed a wizard allowing LiveChat clients to customize their chat experiences for their users by changing the color scheme for the chat window, adding pre-chat questions, and a post-chat survey.
- Built an API for an internal dashboard showing sales and usage statistics.
Software Developer
CCIG
- Designed and implemented a quality assurance application—including a dynamic survey generator and HTML5 audio player. I also developed a back-end service that selected a random sample from a pool of all sales calls recorded on a previous day.
- Wrote, specified, designed, and developed an applicant-tracking system according to HR department requirements.
- Migrated the internal apps from a legacy homegrown PHP framework to Symfony.
Experience
Stack Overflow
https://stackoverflow.com/users/2422778/mike-szyndelStagelink
The things that I'm most proud of:
• We went through two major redesigns of the website while improving usability, performance, the looks, and user satisfaction.
• I successfully moved away from the monolithic Rails app towards an API—cleanly separating the front-end from back-end with some background services performing the heavy lifting (like emails, and so on).
• I made the right technical decisions by separating different parts of the product codebase and making them communicate via an API. This saved us from many headaches when scaling-up.
• I helped new developers quickly get proficient with Stagelink's code and systems—to decrease the bus factor.
Pipedrive Gem
https://github.com/mszyndel/pipedrive-rubyWe started to use a gem to make our lives easier, but the code was pretty terrible. In my free time, I started refactoring it and bringing the quality (and code coverage) up a bit—we are planning to release a new version at some point.
Work Done:
• Removed recursion from the paging-handling code.
• Moved the HTTP calls out of the data objects.
• Performed general cleanup of the code.
• Updated the dependencies and made it work with the current Ruby versions.
Education
Master of Science Degree in Computer Science
Wrocław University of Science and Technology - Wrocław, Poland
Skills
Libraries/APIs
Stripe Development, ActiveRecord, REST API, Sidekiq, Stripe Development, Stripe Connect, Node.js, Twilio Development, jQuery, PayPal API, React.js, API, Facebook API, YouTube API, TensorFlow, Slack API, AWS, SendGrid API, OpenAPI, Pipedrive API
Tools
Slack Development, Git, AWS, Jira, GitHub, RSpec, SOFORT, Wirecard, PAYMILL, Asana, Google Workspace, Trello Development, Bitbucket, Confluence, Docker Compose, Amazon Elastic Block Store (EBS), Redux Thunk, SendGrid, Atom, Amazon Elastic Container Service (ECS)
Languages
SQL, CSS3, Sass, HAML, HTML5, CSS, HTML, ECMAScript 6, ES5, JavaScript, Ruby, PHP, Python, GraphQL
Frameworks
Express.js, Redux, Bootstrap, Ruby on Rails, minitest, Ruby on Rails, Ember.js, Jest, React Native
Paradigms
RESTful Development, MVC Design, REST, Agile Development, Management, Back-end Developers, Agile Development, Agile Development, Continuous Integration (CI), Requirements Analysis, Scrum Master Consulting, Agile Development, HIPAA Compliance, ETL
Platforms
Heroku, MacOS, Linux, Amazon EC2, AWS, Docker, Twilio Development, Shopify, AWS Lambda, Apache Kafka, AliExpress
Storage
SQL, Database Administration (DBA), Memcached, PostgreSQL, Amazon S3, MySQL, MongoDB, Redis, Elasticsearch
Industry Expertise
Virtual Coaching, Cybersecurity
Other
Architecture, IT Project Management, API Integration, Web Scraping, Braintree, Full-stack, Infrastructure, Payment Gateways, QA Testing, QA Leadership, Quality Assurance Engineering, Software QA, Software Architecture, APIs, CSV File Processing, Web Development, Mobile Back-end, Back-end Developers, Back-end Developers, Back-end Developers, RESTful Services, Web Development, Ruby Gems, High Code Quality, Interim CTOs, Business Requirements, Technical Leadership, ActiveAdmin, IT Consultant, System Integration, Design Consulting, Solution Architecture, Data Modeling, Requirements & Specifications, Stripe Payments, Leadership, Team Leadership, E-commerce marketing, Technical Architecture, Lambda Functions, Payment APIs, System Security, Financial Data, Technical Design, OpenID Connect (OIDC), Storybook, Enzyme, Dynamics CRM 365, CRM APIs, Serverless, Scaling, Performance, Cargo & Shipping, Hiring, Interviewing
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