Oleh Tsyhulov
Senior Back-end Developer
Highly accomplished Back-end Lead Developer with over 6 years of experience, including 3 years as a Lead Developer on a large-scale project. I specialize in designing, developing, and optimizing scalable, high-performance microservices architectures, overseeing architectural decisions, and driving technical initiatives for projects with 30+ microservices. A results-driven and detail-oriented professional, I am a proactive problem-solver, committed to continuous learning, and excel as a natural leader and collaborative team player in building innovative solutions from the ground up.
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Work Experience
Lead Back-end Developer
Global Cloud Team - (NDA), Ukraine | Apr 2021 – Present
Industry: Sales | Project Type: Customer data source + CRM | Team Size: Up to 40 people
Click to expand/collapseSpearheaded the development and architectural design of a sophisticated sales automation platform comprising 30+ microservices, each optimized for varying load levels and automatic scaling.
Played a pivotal role in planning and implementing key technical solutions for a comprehensive platform featuring lead management, data export, sales automation, queue services, campaign management, automated sales funnels, smart dialing, SMS, native mailing system, AI responses, payment processing, and intelligent analytics.
- Successfully built and launched an integrated CRM system from scratch within the product.
- Drove and implemented a robust payment system.
- Led the implementation of complex real-time data export features, including comprehensive validations, email/phone validations, and CRM uploads.
- Achieved significant improvements in email deliverability and transitioned to native mailbox service handling (Gmail, Outlook, SMTP integration, error handling, email search, webhooks, bounce/reply/OOO detection, open/click tracking), eliminating third-party dependencies.
- Drove the implementation of AI sequencing features, enhancing platform capabilities and user experience.
- Optimized performance across various subsystems and significantly improved scheduling algorithms for future user events (mailing, dialing, tasks).
- Deepened expertise in DevOps practices, contributing to robust and efficient deployment pipelines.
Key Technologies: NestJS, Node.js, TypeScript, JavaScript, Ruby, K8s, Jenkins, Grafana, Docker, PostgreSQL, MongoDB, Redis, OpenSearch, Microservices, AWS (extensive suite).
Soft Skills: Business Communication, Problem-Solving, Team Collaboration, Leadership, Proactiveness.
Instructor
DevEducation | Oct 2021 - Apr 2022 | Dnipro, Ukraine
Click to expand/collapseLed a 7-month course covering Base JavaScript/TypeScript and Back-end Specialization.
Covered Key Technologies: Typescript, Mongoose ODM, Node.js, PostgreSQL, NestJS, SQL, MongoDB.
Back-end Developer
Global Cloud Team - (NDA), Ukraine | Jan 2021 – Apr 2021
Industry: Trading | Project Type: Trading social platform | Team Size: 6 members
Click to expand/collapseSuccessfully migrated legacy Ruby functionality to NestJS, integrating with MetaTrader 4.
Accelerated platform performance by 3.5x through comprehensive code optimization, strategic indexing, and fine-tuning of SQL queries.
Key Technologies: NestJS, Redis, TypeScript, Docker, Linux, PostgreSQL.
Lead Back-end Developer
Global Cloud Team - (NDA), Ukraine | Sep 2020 – Feb 2021
Industry: Service | Project Type: Polygraph analytic tool | Team Size: 6 members
Click to expand/collapseLed the project from inception, actively collaborating with clients on idea conceptualization and implementation strategies.
Designed and built a comprehensive platform for polygraph examiners, enabling creation and management of reports, security schemes, and graphs.
Implemented automated risk level detection and automatic scheduling of polygraph tests and personnel.
Integrated with external monitoring systems (e.g., YouControl) to generate extensive reports with detailed diagrams.
Key Technologies: NestJS, Redis, TypeScript, Jenkins, Docker, Linux, PostgreSQL.
Back-end Developer
Global Cloud Team - (NDA), Ukraine | Jun 2019 – Sep 2020
Industry: Blockchain | Project Type: Social network/Marketplace | Team Size: Up to 12 people
Click to expand/collapseDeveloped and implemented core logic on top of the Hive blockchain.
Pioneered the implementation of personalized L2 website generation based on blockchain technology and integrated internal monetization mechanisms.
Developed a review monetization system, enabling users to earn cryptocurrency for various activities through weighted voting.
Significantly optimized blockchain interaction and drastically improved database interaction efficiency.
Deployed and managed a Blockchain Node for block signing, ensuring robust system operation.
Key Technologies: Node.js, Blockchain, MongoDB, Redis, JavaScript, Jenkins, Docker, pm2, Linux, PostgreSQL.
Soft Skills: Business Communication, Problem-Solving, Team Collaboration.
Skills
Programming Languages
- TypeScript
- JavaScript
- Ruby
Frameworks
- NestJS
- Node.js
Cloud Platforms (AWS)
- CloudWatch, RDS, Secrets Manager, Glue, EKS, ECR, S3, SQS, SNS, EC2, OpenSearch, VPC, Lambda, API Gateway, EventBridge
Databases
- PostgreSQL
- MongoDB
- Redis
- OpenSearch
DevOps & Tools
- Docker
- Kubernetes (K8s)
- Jenkins
- Grafana
- pm2
- Linux
- CI/CD
Architecture & Methodologies
- Microservices Architecture
- System Design
- API Development
- Blockchain
- AI Technologies
- Architectural Design
- Performance Optimization
- Scalability
- Agile Methodologies
Soft Skills
- Leadership
- Team Collaboration
- Problem-Solving
- Detail-Oriented
- Proactive
- Business Communication
Education & Languages
Education
Bachelor of Engineering
Prydniprovska State Academy of Civil Engineering and Architecture (PSACEA)
Dnipro, Ukraine | 2010 – 2015
Engineering Course
DevEducation
Dnipro, Ukraine | Jan 2019 – Jun 2019
- Applied knowledge of software development lifecycle and programming fundamentals relevant to backend systems.
Languages
- Ukrainian: Native
- English: Upper-Intermediate (B2+)
Get In Touch
Feel free to reach out for collaborations or any inquiries.
Email: contact@olehtsyhulov.tech
Phone:
📱 Contact via email for
phone number
LinkedIn: linkedin.com/in/oleh-tsyhulov-90b39b1a0
Location: Dnipro, Ukraine
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