Bullfinch Recruitment

Senior Back-End Engineer

Sofia, BGFull TimePosted Oct 26, 2026

Requirements at a glance

Senior Back-End Engineer at Bullfinch Recruitment is a full-time role based in Sofia, BG. It does not mention visa sponsorship. Key skills include JavaScript, TypeScript, Node.js, and MongoDB. Applications are submitted through Breezy HR.

Visa sponsorship
Not mentioned in the posting
Application platform
Breezy HR

Skills in this posting

  • JavaScript
  • TypeScript
  • Node.js
  • MongoDB
  • REST APIs

Extracted automatically from the job description. Confirm details in the full posting below.


Senior Back-End Engineer

Sofia, Bulgaria | Hybrid | Full-time

About

Global technology company providing B2B SaaS solutions for online sports platforms. The company develops sportsbook software and data-driven technology that enables betting operators to deliver reliable, high-performance sports betting experiences across international markets.

The Role

We are looking for a Senior Back-End Engineer to join our team in Sofia, contributing to the development and evolution of our sportsbook platform.

You'll work within a microservices-based architecture, building and maintaining API-driven services that support complex, high-performance applications. Working closely with other engineers, you'll contribute to new feature development, system optimisation and the continued improvement of our technical infrastructure.

Key Responsibilities

  • Develop and maintain API-based backend services and applications.
  • Build and enhance services using JavaScript, TypeScript, Node.js and NestJS.
  • Contribute to the design and implementation of new product features.
  • Work with a microservices architecture and technologies including MongoDB and Pulsar.
  • Optimise applications for performance, scalability and reliability.
  • Troubleshoot and resolve complex technical issues.
  • Write clean, maintainable code and contribute to code reviews and engineering best practices.
  • Collaborate with colleagues across an international engineering team.

What We're Looking For

  • Strong commercial experience with Node.js development.
  • Proficiency in JavaScript (ES6+) and/or TypeScript.
  • Experience working with NestJS.
  • Good understanding of RESTful APIs and backend service design.
  • Strong analytical and problem-solving skills.
  • Excellent communication and teamwork abilities.
  • Good written and spoken English.

Desirable Experience

  • Experience operating mature API products in production.
  • Exposure to high-load systems and scalable architectures.
  • Experience with Apache Pulsar, Aerospike or similar technologies.
  • A degree in Computer Science, Software Engineering, Mathematics or a related discipline.

Package:

  • An international and multicultural working environment.
  • Hybrid working in Sofia.
  • Flexible working hours.
  • Up to 24 days of paid annual leave.
  • Food vouchers and additional health insurance.
  • Sports card and office perks.
  • Career development opportunities and team-building activities.

Location: Sofia, Bulgaria | Working arrangement: Hybrid | Employment type: Full-time

Keep exploring

View all software engineering jobs