# Oleh Zaporozhets > Lead Software Engineer at Yourco Location: Chicago, Illinois, United States Profile: https://flows.cv/oleh Experienced Software Engineer with a Master’s Degree in Computer Science and over 8 years of experience building high-load applications. Demonstrated strong development, leadership, and management skills. Dedicated to delivering high-quality work from conception to execution. Proficient in microservices architecture, cloud solutions, and multiple programming languages. Achievements: • Successfully prepared a backend application for SOC 2 Certification, resulting in zero non-conformities discovered during the third-party audit. • Designed and built a RAG-based chatbot system from scratch, including a continuous data ingestion pipeline and vectorization of both incoming and historical data, and source citation support for generated answers. • Decomposed a monolithic application into multiple microservices and migrated them from GCP App Engine to GCP Cloud Run, leveraging a serverless approach with zero-instance scaling—resulting in a 20% reduction in cloud costs. • Reduced company expenses by deprecating the old payment service, building a new efficient payment service, and successfully migrating 250,000 customers in a multi-step rollout using a canary release approach. • Designed and implemented new functionality in a legacy project with minimal internal resources by leading technical vendor evaluations. Successfully outsourced the effort, reducing estimated costs from $60,000 to $30,000, and accelerating feature delivery. • Increased free-trial sign-ups by 15% by migrating blog pages from a React monolith to Next.js microservices, leading to a spike in organic traffic as key SEO and page speed metrics were significantly improved. Skills: • Languages: TypeScript / JavaScript, Python, SQL, C# • Back End: Node.js, NestJS, Express, Flask, GraphQL, Apollo, WebSockets, .NET Framework • Front End: React, Next.js, Redux, Tailwind CSS, HTML, CSS (Sass/SCSS) • Infrastructure: Kafka, Docker, Kubernetes, Terraform • Databases: PostgreSQL (Prisma ORM), Redis, MongoDB • AWS: Lambda, API Gateway, IAM, S3, EC2, DynamoDB, RDS, VPC Networking, SNS, SQS, Step Functions • GCP: Cloud Run, Compute Engine, Cloud Storage, Pub/Sub, Cloud Load Balancing, VPC Networking, Memcached • CI/CD: TeamCity, GitHub Actions, Bitbucket Pipelines • Observability & Ops: Prometheus, Grafana, Graylog • Build Tools: Webpack, Vite Testing: Jest, Cypress, Selenium, Taurus ## Work Experience ### Lead Software Engineer @ Yourco Jan 2026 – Present | Chicago, IL – Lead a team of 5 engineers, providing technical direction, mentoring, and ownership of delivery. – Designed and built a RAG-based chatbot system from scratch, including a continuous data ingestion pipeline and vectorization of both incoming and historical data, and source citation support for generated answers. – Drove infrastructure migration to Terraform, establishing CI/CD for infrastructure as code, importing legacy resources, and managing ongoing infrastructure expansion. ### Senior Software Engineer @ Yourco Jan 2024 – Jan 2026 | Chicago, IL – Successfully prepared a backend application for SOC 2 certification. – Led the decomposition of a monolithic application into dozens of microservices, introducing NestJS, migrating services to GCP Cloud Run with a serverless architecture, and using GCP Pub/Sub as the messaging backbone. – Introduced and implemented integration testing across services. – Reduced deployment time from one hour to 15 minutes by implementing a robust CI/CD pipeline. – Built infrastructure for feature toggles and canary release deployments using LaunchDarkly, and developed a dedicated microservice to manage feature flags at the tenant level. ### Senior Software Engineer @ DataArt Jan 2021 – Jan 2024 | Cracow – Designed and executed Taurus-based stress tests to validate system readiness for 5x peak load. – Built a Redis caching layer between a microservice and a vendor API, cutting external API calls by 70%. – Built an event-driven communication system using Kafka to replace a request-response model, resulting in more decoupled microservices, including idempotency mechanisms to ensure reliable message processing. – Designed and ran complex multivariate A/B tests, using the LaunchDarkly platform for feature toggles and controlled rollouts. – Designed and maintained a microservice using GraphQL as the API interface and PostgreSQL for data storage. ### Full Stack Developer @ Lambda Team Jan 2019 – Jan 2021 | Kyiv, Ukraine - Built serverless applications using AWS (Lambda, IAM, S3, EC2, SQS, SNS, DynamoDB, RDS, Route53), TypeScript, Node.js, and Python to deliver complex architectural solutions. - Collaborated in cross-functional teams to develop full-stack projects from scratch, integrating both backend and frontend components. ### Front End Developer @ Lambda Team Jan 2018 – Jan 2019 | Kyiv, Ukraine - Developed SPAs, SSR-enabled SPAs, Chrome extensions, and Electron applications. - Implemented pixel-perfect designs through close collaboration with UI/UX designers. ## Education ### Master's degree in Computer Science State University of Telecommunications Jan 2020 – Jan 2022 ### Master's degree in Engineering Kryvyi Rih National University Jan 2016 – Jan 2018 ### Bachelor's degree in Engineering Kryvyi Rih National University Jan 2012 – Jan 2016 ## Contact & Social - LinkedIn: https://linkedin.com/in/oleh-zaporozhets - GitHub: https://github.com/oleh-zaporozhets - Website: https://oleh-zaporozhets.medium.com/ --- Source: https://flows.cv/oleh JSON Resume: https://flows.cv/oleh/resume.json Last updated: 2026-03-22