NIKOLAI GOLUB

ConsenSys - Remote
ConsenSys is the leading Ethereum software company.

Senior Protocol Engineer

• Implementation of a rollup, scaling solution for Ethereum blockchain, written in Rust from proof of concept to production ready services with PostgreSQL and Kafka as data storages and deployed on Kubernetes.
• Developing, testing and deployment of smart contract parts of the rollup.
• Integrating Zero Knowledge circuits, written in Golang.
• Analyzing performance of Rust codebase, writing benchmarks, identifying bottlenecks and refactoring architecture to meet performance requirements.
• Writing documentation and contributing to specification.

• Improved performance of the main flow of execution to 5k transactions per second. Reduced smart contract gas usage by approximately 30%.
• Designed contract based testing between Rust, Golang and Solidity codebases which simplified cases around zero knowledge proofs.
• Tuned metrics collecting and built Grafana dashboards for performance benchmarks analysis.

Booking.com - Amsterdam, Netherlands
Booking.com is an engine for lodging reservations.

Software Developer

• Deployment of highly available services with millions of users. Firefighiting, investigating and acting on "Reason for Outage" process.
• Back end development of guests and partners facing web sites.
• Run and analyze A/B tests.

• Built micro services for integration with tours & activities providers for scalable and high frequency import of new supply, with Java, MySQL, Kafka. Built alerting and monitoring.
• Built continuous delivery pipeline on Gitlab with Kubernetes, ElasticSearch and Python.
• Improved performance of entrepreneurial partners by integrating cancellation policy recommendation model.
• Contributed to community driven projects: Python libraries, developer tools.
• Won hackathon with tool for visual text editor for copywriters for Sketch, where I built backend part.

Toptal - Remote
Toptal is an exclusive network of the top freelance software developers and designers in the world.

Software Developer

• Full-stack development of the web portal for EverCharge, electric vehicle charging company. Technologies: Flask, PostgreSQL, Celery, AWS, Stripe
• Back end development of API authorization layer for Civinomics, crowd-sourced polling platform. Technologies: Django REST Framework, MySQL
• Full-stack development of the web portal for Walkio pet care services company. Technologies: Django, PostgreSQL DigitalOcean, Stripe
• Front-end development for Staffmatch, french outstaffing company. Technologies: React.js, Redux and ES6.

• Developed web portal from scratch for EverCharge. It has automated billing, customer signup and payout logic. Increased number of automated tests from 0 to around 500 for faster delivery.
• Decreased cost of monthly billing by migrating to Stripe for EverCharge.
• Established SMS communication between customers and pet walkers using Twillio for Walkio.

Positive Technologies - Saint Petersburg, Russia
Positive Technologies is a leading provider of vulnerability assessment, compliance management and threat analysis solutions.

Software Test Engineer

• Development automated tests for several subsystems of Web Application Firewall
• Consultation for performance testing.

• Improved regression testing by introducing Selenium automated tests for Web UI of Web Application Firewall.

Dino Systems - Saint Petersburg, Russia
DINS (DINO Systems) is an R&D center of RingCentral, Inc. (USA) - leading provider of cloud-based business telephone system for small and medium businesses.

Senior Performance Test Engineer

• Full process of performance testing from feature understanding and test planing to running developed tests and data analysis.
• Development automated performance tests for SOAP API (C#) and Telephony system (Python).
• Strong collaboration with Operations and Dev teams for fast problem solving and improving testing process.

• Reduced the time of creating a performance test report by 30% by suggesting, designing and developing a web portal for test results. Based on Python and Django, PostgreSQL, Celery and AmCharts.

Devexperts - Saint Petersburg, Russia
Devexperts is a financial software provider of professional software systems for on-line brokerage, exchange, and financial activities mostly on stock, options, and Forex markets.

Performance Test Engineer

• Performance tests configuration, run, validation and data analysis
• Administration of test environment in the Amazon Web Services

• Developed a software for automatic collection and processing performance tests results. It decreased human errors and data loss.