Middle JavaScript/Node.js Developer (Telecom domain)

Kharkiv Kyiv Lviv JavaScript Node.js

Required skills

JavaScript / strong
Node.js / good
React / good
English / strong

We welcome a person with in-depth knowledge of JavaScript who wants to open up space for professional development:

  1. Improve your professional skills using the latest technology, following the best practices and high standards that Sigma adheres to. Together we will compile your personalized professional development roadmap.
  2. Take soft skills to the next level by being able to present new ideas and actively suggest improvements, etc. Communication is a very important part of our project; with its help, we build trust.

We would like to see you in our team if you are ready to be the one who supports and gives a clear vision to the Customer, takes ownership of the product, and can contribute to its development.


We work in Telecom domain. Our project is one in a chain that makes network rollout worldwide possible. We build an integrations part of workflow management system that is the backbone of the business with almost 100,000 employees. This system is used to manage thousands of projects related to mobile network rollouts from Japan to Mexico.

Overall, this is a huge project with massive amounts of data, with more than 150 servers as the infrastructure, and some servers are 96 core/1TB RAM monsters.

Our project is not just the interface but also a cashing/search solution that allows users to quickly search among huge amounts of data available in the system. For caching, we use MongoDB with Mongoose ORM.

The backend of our caching solution is written in:

  • Node.js/Express
  • ESLint with Google’s rules
  • Jest for unit tests
  • GitLab for code reviews

We are gradually rewriting the existing codebase to leverage the functional approach, using Ramda.js as our main helper library.

Some of the foreseeable future tasks: implementation of faster cache update cycle via Apache Kafka, switching to ELK stack for logging, switching to HTTP/2 in the UI.

About the team:

4 Developers, 2 Test Engineers, and PM. We are also working as one team with other sub-contract company, and there is a Scrum Master, Architect, and 3 Developers from their side.


  • Strong experience with JavaScript
  • Good knowledge of Node.js
  • Knowledge of React.js and practical experience with it
  • Experience with GitLab
  • Upper-Intermediate level of written and spoken English

Experience with the following technologies will be a plus:

  • Redux
  • MongoDB
  • Functional programming skills (we’ll teach you if needed)

Personal Profile

  • Good communication skills
  • Ability to take ownership for deliverables, rather than task-oriented approach


  • Design separate components, modules, classes, database tables, etc.
  • Code, debug, document, and maintain portions of software, unit and integration testing
  • Comply with the best engineering practices, the technical standards and the quality criteria set forth on the project
  • Report status and progress according to the project and Company demands
  • Spot current deficiencies in the development process, adopted procedures and engineering practices, environment configurations, etc., and suggest improvements


  • Health & Legal support
  • Discount program
  • Sport activities
  • Outstanding offices
  • Comfortable place in a cozy room
  • Continuous education
  • Flexible schedule
  • Remote work
  • Diversity of Domains & Businesses
  • Variety of technology

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