Serge Ponomarov
Verified Expert in Engineering
Web Developer
Serge is a senior software engineer who has built massive web applications from scratch and designed complex back-end architecture to withstand high loads. He has worked remotely on a full-time basis with clients, primarily from the US and Canada across various industries, including eCommerce, blockchain, and education.
Portfolio
Experience
Availability
Preferred Environment
Slack, Jira, Git, MacOS, Visual Studio Code (VS Code), Sentry, Grafana, Kibana, Zsh
The most amazing...
...thing I've built from scratch is a distributed eCommerce platform that now processes seven-digit monthly revenues across thousands of stores.
Work Experience
Senior Software Engineer
Toptal Clients
- Worked for clients as part of a network of top-tier remote software developers that accepts only the top 3% of freelance talent.
- Served mainly US and Canadian clients across industries such as eCommerce, construction, publishing, education, automobiles, and music.
- Completed a long-term client engagement that lasted over five years.
Software Development Engineer III
GoCardless
- Worked in a team responsible for building and maintaining banking integrations in a fintech unicorn that processes over $30 billion of payments annually across more than 30 countries.
- Extracted business logic from our monolith app into microservices to help achieve our scalability goal of handling 16 million payments per day.
- Rebuilt a complex database query with many joins from the ground up using a denormalized partitioned table, taking it from 25 minutes to 1.5 seconds, achieving a 99.9% improvement.
- Led a project that enabled us to run payment submission pipelines in different time zones, increasing our competitiveness in foreign markets.
- Performed code reviews actively and mentored new hires.
Senior Back-end Developer
CommerceHQ
- Built the back end from scratch for an eCommerce platform similar to Shopify that now processes 7-digit revenues monthly across thousands of stores. My code handled over $100 million worth of checkouts in total.
- Devised a robust architecture for high loads, where customers’ stores can be quickly moved across servers thanks to our own DNS setup.
- Developed systems on my own that whole companies would build, such as a customer support system with MongoDB and WebSockets.
- Integrated over a dozen third-party APIs into our platform and built our own REST API that's open to others.
- Worked remotely with a small team of awesome people that competed with giants like Shopify, and met with them on company retreats across Europe.
Experience
CommerceHQ
https://commercehq.com/I was the first engineer and started the development from scratch. I've been working on it for five years, and I'm truly proud of what we've built as a team.
ZenFuse
https://zenfuse.io/I built the minimum viable product (a back-end REST API) for this blockchain startup that went on to a successful fundraise.
Wine Pairing App
https://epic-poitras-73d63f.netlify.app/I built this as a fun personal project to use during the 2020 COVID-19 lockdown days and to brush up on my front-end development skills in JavaScript and Vue.js.
Toptal React Academy
https://vimeo.com/toptal/review/505888912/c4bbb5999f?utm_medium=emailSkills
Languages
HTML, PHP, Ruby, CSS, SQL, CSS3, JavaScript, HTML5, GraphQL, ECMAScript (ES6), Sass, Python
Frameworks
Yii, Ruby on Rails (RoR), Express.js, Bootstrap, Redux, OAuth 2
Libraries/APIs
REST APIs, Stripe API, Vue, Node.js, React, Stripe, Context API, Twilio API, Facebook API, PayPal API, jQuery
Paradigms
REST, Model View Controller (MVC), Object-oriented Programming (OOP), DevOps, Agile Software Development, Continuous Integration (CI), Agile
Other
Webhooks, PayPal, Distributed Systems, APIs, API Integration, SSL, DNS, OAuth, VCS, Ajax, WebSockets, Caching, Apollo, Axios, Cloudflare, Prometheus, CI/CD Pipelines
Tools
PhpStorm, Git, TeamCity, Jira, Slack, Composer, NGINX, Confluence, Notion, GitHub, Sentry, NPM, RabbitMQ, Stripe Checkout, Grafana, Kibana, Zsh
Platforms
Ubuntu, MacOS, Amazon Web Services (AWS), OS X, Linode, Firebase, Heroku, Netlify, Visual Studio Code (VS Code), Google Cloud Platform (GCP)
Storage
PostgreSQL, Amazon S3 (AWS S3), MySQL, Redis, MongoDB, Google Cloud
Certifications
Toptal React Academy Graduate
Toptal, LLC
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