Sanja is available for hire
Hire SanjaSanja Zdravkova
Verified Expert in Engineering
Back-end Developer
Skopje, Macedonia
Toptal member since August 31, 2020
Bio
Sanja is a back-end engineer with 8+ years of experience, specializing in Node.js, TypeScript, and AWS. She builds scalable, secure systems and thrives in collaborative environments. As a team player with strong problem-solving skills, she is always eager to learn and adapt to new technologies. Sanja seeks an opportunity to contribute technical expertise and collaborate in a dynamic environment to build efficient, high-performing applications.
Portfolio
Freelance Clients
Node.js, TypeScript, Redis, BullMQ, TypeORM, PostgreSQL, NestJS...
Yahoo! - Media Platform Innovation
Node.js, Neo4j, Amazon DynamoDB, Express.js, GraphQL, Amazon Web Services (AWS)...
Yahoo! - Media Platform Innovation
Node.js, Amazon Web Services (AWS), Neo4j, Amazon DynamoDB, GraphQL, Express.js...
Experience
- JavaScript - 9 years
- Back-end - 9 years
- Node.js - 8 years
- Express.js - 8 years
- Amazon Web Services (AWS) - 8 years
- TypeScript - 8 years
- AWS Lambda - 8 years
- MySQL - 4 years
Availability
Full-time
Preferred Environment
Node.js, Express.js, TypeScript, Amazon Web Services (AWS), Visual Studio SDK, MacOS
The most amazing...
...project I've led is designing and building a scalable microservices solution for a new partner at Alite, managing a team and delivering on time.
Work Experience
Back-end Engineer
2024 - PRESENT
Freelance Clients
- Developed and implemented RESTful APIs for user and task management using NestJS.
- Designed and built PostgreSQL data structures and implemented CRUD operations using TypeORM.
- Built and implemented a notification system for task reminders using Redis, BullMQ, and Firebase Cloud Messaging.
Technologies: Node.js, TypeScript, Redis, BullMQ, TypeORM, PostgreSQL, NestJS, Firebase Cloud Messaging (FCM), Express.js, Git, REST APIs, JavaScript, Back-end, Next.js, CI/CD Pipelines, APIs
Back-end Engineer (Node.js)
2023 - 2023
Yahoo! - Media Platform Innovation
- Implemented Redis for faster job status responses.
- Implemented new features on the back end using Java and front end React for managing elements across different Yahoo systems.
- Provided on-call support across multiple platforms for troubleshooting and resolving issues, ensuring timely resolution of bugs.
Technologies: Node.js, Neo4j, Amazon DynamoDB, Express.js, GraphQL, Amazon Web Services (AWS), Redis, Git, REST APIs, Serverless Architecture, JavaScript, TypeScript, AWS Lambda, Microservices Architecture, Docker, Bash Script, Kubernetes, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Back-end API Engineer
2022 - 2023
Yahoo! - Media Platform Innovation
- Developed and deployed Dockerized Bash scripts on AWS EKS.
- Introduced AWS Lambdas to improve startup and overall time for various jobs that were previously working as containers.
- Maintained, updated, and fixed bugs on Lambdas, Docker files, and scripts.
Technologies: Node.js, Amazon Web Services (AWS), Neo4j, Amazon DynamoDB, GraphQL, Express.js, Docker, Bash Script, Kubernetes, Git, REST APIs, Serverless Architecture, JavaScript, TypeScript, AWS Lambda, Microservices Architecture, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Node.js Back-end Engineer
2022 - 2022
Yahoo!
- Implemented Elasticsearch to optimize performance for CRUD operations, enhancing the efficiency of data retrieval and management.
- Developed a new Lambda function with asynchronous logic from scratch to handle time-consuming workflows, improving processing efficiency and reducing latency.
- Managed updates for various Lambda functions, including upgrading libraries and Node.js versions, ensuring compatibility and optimizing performance for seamless execution.
Technologies: Node.js, Amazon Web Services (AWS), Neo4j, Amazon DynamoDB, GraphQL, Express.js, Git, REST APIs, Serverless Architecture, JavaScript, TypeScript, AWS Lambda, Microservices Architecture, Docker, Kubernetes, Bash Script, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Back-end Engineer (Node.js)
2021 - 2022
Yahoo!
- Implemented WebSockets as a way of notifying the client of statuses and changes.
- Worked with engineers across the company to build new features and large scales.
- Identified and debugged bottlenecks to improve end-user experience and evaluated efficient technological changes to reduce resource consumption and request latency.
Technologies: Amazon Web Services (AWS), Neo4j, Amazon DynamoDB, Node.js, GraphQL, TypeScript, Express.js, Git, REST APIs, Serverless Architecture, JavaScript, AWS Lambda, Microservices Architecture, Docker, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Software Engineer
2016 - 2022
Alite international
- Developed and implemented microservice architecture-based and serverless-based solutions for various projects using Node.js, TypeScript, Express.js, and AWS services such as Lambda, API Gateway, DynamoDB, and ECS.
- Implemented a microservice from scratch to facilitate communication with a 3rd-party system using the SOAP protocol using TypeScript and Node.js.
- Implemented a user management microservice from scratch using Amazon Cognito, TypeScript, Node.js, and Express.js.
- Contributed to the design of a two-way integration between Jira and the Liverpool helpdesk system and successfully implemented the solution using AWS Lambda, DynamoDB, TypeScript, Node.js, and Express.js.
- Implemented a solution for migrating thousands of users from the LFC database to Amazon Cognito as well as the whole user management service using AWS services, TypeScript, Node.js, and Express.js.
- Led a team of six members in the development of a customized solution for a new partner using microservices architecture, AWS services, TypeScript, Node.js, and MySQL.
- Designed back-end architecture and implemented key back-end components while leading both front-end and back-end teams.
Technologies: Amazon DynamoDB, Microservices Architecture, SOAP, MySQL, JavaScript, AWS Lambda, REST APIs, Git, Node.js, Express.js, TypeScript, Amazon Web Services (AWS), Serverless Architecture, PostgreSQL, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Back-end Engineer (Node.js)
2020 - 2021
Yahoo!
- Designed, built, and maintained GraphQL and REST APIs.
- Designed and built Neo4j, DynamoDB, and Elasticsearch database structures.
- Developed and maintained lambdas using a serverless framework.
- Integrated with many 3rd-party APIs across the Yahoo platform.
Technologies: Amazon Web Services (AWS), Neo4j, Amazon DynamoDB, Node.js, GraphQL, TypeScript, Express.js, Git, REST APIs, Serverless Architecture, JavaScript, AWS Lambda, Microservices Architecture, Docker, Back-end, AWS SDK, CI/CD Pipelines, Microservices, APIs
Junior Developer
2015 - 2016
Artistika
- Developed and deployed a fully responsive website, handling both the front and back end as the sole developer. Utilized HTML, CSS, JavaScript, jQuery, .NET, Umbraco, and SQL.
- Redesigned a whole website for a fitness community, making it responsive to all screen sizes. Utilized HTML, CSS, JavaScript, and jQuery.
- Communicated directly with the clients for most of the projects.
Technologies: HTML, CSS, MySQL, JavaScript, REST APIs, Git, Back-end, SQL, APIs
Experience
Swiss Re – iptiQ
An online platform for buying insurance policies. Automated underwriting, manual underwriting, and management of the policies are integrated through 3rd-party systems, microservice architecture using AWS services and Node.js for the back-end part, and Sitecore (.NET) for the front-end part. The microservices are reused for multiple distribution partners who are willing to integrate with this solution.
I worked as a back-end developer on this project, responsible for implementing solutions, resolving bugs, writing integration and unit tests, and developing microservices from scratch. I also contributed to designing solutions for various features. Later, I was promoted to lead back-end developer, where I led the solution implementation, managing a team of developers to ensure the successful delivery of the project while maintaining high-quality standards.
I worked as a back-end developer on this project, responsible for implementing solutions, resolving bugs, writing integration and unit tests, and developing microservices from scratch. I also contributed to designing solutions for various features. Later, I was promoted to lead back-end developer, where I led the solution implementation, managing a team of developers to ensure the successful delivery of the project while maintaining high-quality standards.
Liverpool LFC
An online platform for connecting with the fans of Liverpool. User management of the fans (thousands of them) was mostly our focus. Another big success was the two-way integration between Jira and their helpdesk system (Solarwinds) for synchronization on every ticket on both systems.
I worked as a back-end engineer on this project using a serverless architecture, AWS Lambda, DynamoDB, and Node.js technology.
I also played a big part in creating the solution designs for the two-way integration between Jira and the client's system and the solution for migrating the users.
I worked as a back-end engineer on this project using a serverless architecture, AWS Lambda, DynamoDB, and Node.js technology.
I also played a big part in creating the solution designs for the two-way integration between Jira and the client's system and the solution for migrating the users.
Composer – Web Platform for Building Next-Generation Immersive AR Experiences
The project was a web platform designed to build next-generation immersive augmented reality (AR) experiences. It incorporated both serverless architecture and Kubernetes-based microservices to efficiently handle long-process workflows and ensure scalability. The platform enabled content creators to seamlessly build, manage, and deploy AR experiences, enhancing user engagement across various digital environments.
In this project, I was responsible for designing and implementing backend solutions, ensuring smooth integration of various services, and handling the orchestration of long-running workflows. I contributed to the development of both serverless and microservices components, optimizing performance, and ensuring scalability. I also collaborated with cross-functional teams to design and deliver high-quality solutions that met the project’s technical requirements.
In this project, I was responsible for designing and implementing backend solutions, ensuring smooth integration of various services, and handling the orchestration of long-running workflows. I contributed to the development of both serverless and microservices components, optimizing performance, and ensuring scalability. I also collaborated with cross-functional teams to design and deliver high-quality solutions that met the project’s technical requirements.
Education
2013 - 2018
Bachelor's Degree in Computer Science and Engineering
St. Cyril and Methodius University Faculty of Computer Science and Engineering - Skopje, Macedonia
Certifications
SEPTEMBER 2018 - PRESENT
AWS Technical Professional (Digital)
AWS Training and Certification
Skills
Libraries/APIs
Node.js, REST APIs
Tools
Git, AWS SDK, Firebase Cloud Messaging (FCM)
Languages
JavaScript, TypeScript, GraphQL, SQL, HTML, CSS, Bash Script
Frameworks
Express.js, NestJS, Next.js
Paradigms
Microservices Architecture, Serverless Architecture, Microservices
Platforms
AWS Lambda, Amazon Web Services (AWS), Kubernetes, Docker
Storage
Amazon DynamoDB, MySQL, Neo4j, PostgreSQL, Redis
Other
Back-end, APIs, CI/CD Pipelines, SOAP, BullMQ, TypeORM
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