Sergey Okhotnikov
Verified Expert in Engineering
Software Developer
L'Eliana, Spain
Toptal member since July 15, 2021
Sergey has been working remotely for more than ten years. He succeeded in completing remote projects and building remote teams long before it became the main development trend. He acted as a developer and was a part of the QA team in his last working place, where he designed and built the back end and administrative front end from scratch. Sergey is a professional who looks forward to working on high-quality projects—especially in the educational, healthcare, gaming, and IoT industries.
Portfolio
Experience
- SQL - 7 years
- Java - 7 years
- Spring - 6 years
- Amazon Web Services (AWS) - 5 years
- JavaScript - 5 years
- PostgreSQL - 5 years
- React - 4 years
- TypeScript - 3 years
Availability
Preferred Environment
MacOS, Linux, IntelliJ IDEA
The most amazing...
...thing that I've designed and implemented is the education robot platform with Arduino controller, Unity game, and Java server.
Work Experience
CTO | Full-stack Developer
RentsBy
- Created the project's architecture and infrastructure from scratch.
- Built back-end services with Python, Node.js, and Java and deployed them to AWS.
- Developed a web application with React, TypeScript, and Next.js.
- Integrated Stripe and MapBox libraries to the project.
Back-end and Full-stack Developer
Toptal Clients
- Developed Auth0 integration for the back end using Java Spring and Rest client.
- Set up and developed performance tests using REST API, API Gateway, AWS Lambda, and CloudWatch.
- Developed the email parsing flow using AWS Route 53, SES, S3, and Lambda.
- Fixed performance issues of AWS Lambda and API Gateway.
Senior Software Developer
ANAV/Scientific Entertainment
- Created and developed the back end and admin front end from scratch using Java, PostgreSQL, Redis, AWS, React, and Angular. The service covers all needs concerning the client, license, and purchase management for the educational software.
- Implemented developer tools for the team, such as an online dictionary, quest, content, and level editors. AngularJS editors were developed with MongoDB data storage and a REST API service for multimedia client access.
- Designed and built a user behavior analytics system based on AWS S3 and Apache Spark.
- Built a teacher-student communication and file-sharing system using a WebSocket server for chat and S3 with CloudFront and a link signing service for file sharing.
- Managed the teamwork and set up tools including Git, task trackers, and Slack. Planned milestones and wrote tasks for sprints, trained team members, and planned and conducted team meetings and information-sharing sessions.
Software Developer
InformGaz
- Developed pipeline for document transformation from word and text files to database records.
- Implemented tests and validation algorithm for incoming documents.
- Wrote guides and requirements for documentation providers.
Lead Product Manager
PIPE Studio
- Created product design for major game series of the studio.
- Trained, evaluated, and managed junior product managers.
- Conducted negotiations about product design with partners and customers.
- Designed, developed, and tested product prototypes.
Pascal Developer and Technical Writer
LANIT
- Wrote instructions and user guides for new company software products.
- Developed a user guide library program for indexing and searching documentation.
- Conducted software testing for special use case description purposes.
Software Developer
Sikkens Ukraine
- Developed warehouse management system for wholesales company.
- Maintained warehouse management system for wholesales company.
- Implemented product sales report and prediction system.
Experience
RentsBy
https://rentsby.com/Toptal React Accelerator Graduate
okhotnikov.net
https://okhotnikov.net/Savanto
http://www.savanto.fr/savantoNative Speech Recognition plugin
Professor Drozdov School
https://play.google.com/store/apps/details?id=com.ScientificEntertainment.SchoolDrozdovEducation
Bachelor's Degree in Computer Science
National Technical University of Ukraine - Kiev, Ukraine
Certifications
AWS Certified Developer – Associate
Amazon Web Services Training and Certification
Toptal React Accelerator Graduate
Toptal, LLC
Skills
Libraries/APIs
React, REST APIs, Node.js, React Router, Stripe, Mapbox GL, GitHub API
Tools
Amazon CloudFront CDN, GitHub, WebStorm, Apache Maven, GitLab, Git, NPM, Amazon Simple Queue Service (SQS), IntelliJ IDEA, Mathematica, Figma, Amazon Simple Email Service (SES), Amazon CloudWatch, Amazon Elastic Container Service (ECS), Amazon Elastic Container Registry (ECR), Docker Compose, Docker Hub, Amazon Cognito, Auth0
Languages
Java, SQL, JavaScript, HTML, CSS, Java 8, Java 11, TypeScript, C#, HTML5, CSS3, Sass, Swift, Python, Pascal, C++, Delphi, XML, GraphQL, TypeScript 3, JavaScript 6
Frameworks
Spring, Spring Boot, JSON Web Tokens (JWT), Next.js, AngularJS, Redux, Unity3D, Material UI, JavaScript MVC, Jest, Cypress, Spark, Unity, Angular, Apache Spark, Hibernate, Swagger
Paradigms
UX Design, Microservices, REST, API Architecture, Microservices Architecture, Requirements Analysis, Mobile Development, UI Design, Responsive Layout, Serverless Architecture, DevOps, Unit Testing, Management, Web Architecture, Lambda Architecture
Platforms
Amazon Web Services (AWS), Android, Docker, AWS Lambda, Firebase, Mapbox, Vercel, Azure, Linux, Apache Kafka, MacOS, Kubernetes, Visual Studio Code (VS Code), Amazon EC2, Windows, iOS, Mobile, Google Cloud Platform (GCP)
Storage
Databases, Amazon S3 (AWS S3), NoSQL, JSON, PostgreSQL, Redis, MongoDB, MySQL, SQL Stored Procedures, Cloud Firestore, Elasticsearch, Google Cloud, Amazon DynamoDB, PostGIS
Industry Expertise
Project Management
Other
Product Design, Back-end, Full-stack, Front-end, Front-end Development, APIs, Back-end Development, Lambda Functions, User Experience (UX), Gaming, 2D Games, Web Development, API Integration, Webhooks, Web App Development, Remote Team Leadership, Game Development, User Interface (UI), Technical Leadership, Architecture, Chakra UI, OAuth, Software Architecture, Serverless, Integration, Games, 3D Games, DocumentDB, QR Codes, Technical Architecture, Cloud Infrastructure, Team Leadership, DOM, CTO, Startups, Code Review, Product Development, Payment Gateways, Batch File Processing, JavaScript Libraries, Axios, Technical Consulting, Marketing Mix, Electronics, Physics, Game Design, Machine Learning, Responsive UI, RESTful Microservices, WebSockets, Multithreading, Amazon API Gateway, Amazon Route 53, Firebase Cloud Functions, CI/CD Pipelines, AWS Cloud Architecture, Leadership, Web Mapping, Airtable
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