The Project

At VSG Bulgaria, we're building the next generation of financial software and rethinking how we develop it.

With over 20 years of experience in financial technology, VSG Bulgaria develops solutions for complex challenges in the financial industry. Our current focus is modernizing lending and deposit software using modern APIs, microservices, and cloud technologies.

We're also taking a different approach to software development.

AI coding agents like Claude Code, Cursor, and Codex are part of our everyday workflow. We use them throughout the development process to move faster, automate implementation, and focus more of our engineering effort on design, architecture, and solving meaningful problems.

We're looking for a Senior Backend Engineer who already works confidently with AI coding agents and knows how to turn their output into reliable, secure, production-ready software.

You'll have the opportunity to shape both the systems we build and the engineering practices behind them.

What You'll do

You'll take ownership of backend solutions throughout their lifecycle, from technical design to production.

• Design and develop backend services and APIs for modern financial applications, focusing on performance, scalability, and security.
• Use AI coding agents as a core development tool to accelerate implementation, testing, and refactoring while maintaining full ownership of code quality and architectural decisions.
• Build MCP servers and integrations that securely connect our APIs with AI platforms such as Claude, ChatGPT, and Grok.
• Own the delivery of your solutions, including automated testing, CI/CD pipelines, deployment, and production reliability.
• Improve how we work with AI, establishing effective agent instructions, development workflows, code review practices, and engineering guardrails.
• Collaborate and share knowledge with experienced engineers and international colleagues, contributing to technical decisions and mentoring others.

We value engineers who take initiative, challenge existing approaches, and look for smarter ways to solve problems.

What We're looking for

We're looking for someone with strong engineering fundamentals, hands-on experience with AI-assisted development, and the confidence to own technical decisions.

Engineering experience

• 5+ years of professional backend development experience, including at least 2 years in a senior engineering role.
• Strong proficiency in a backend language such as C#/.NET, Go, or Rust, with the ability to work effectively in our .NET environment.
• Solid understanding of relational databases, including data modeling, indexing, query optimization, transactions, and migrations.
• Experience designing and maintaining production APIs, with a good understanding of authentication, authorization, API security, and reliable integrations.
• Hands-on experience with cloud platforms (GCP, AWS, or Azure), Docker, and familiarity with Kubernetes or similar environments.
• Strong understanding of automated testing, CI/CD, code reviews, and production monitoring.
• Ability to make architectural decisions, solve complex technical problems, and communicate effectively with technical and non-technical colleagues.
• Fluent written and spoken English.

AI-native development experience

• You actively use AI coding agents such as Claude Code, Cursor, Codex, or similar tools in your daily work.
• You know how to break down complex requirements, guide agents effectively, and critically evaluate the code they generate.
• You're comfortable using AI across the development lifecycle, from implementation and testing to debugging and refactoring.
• You understand that AI accelerates development, but engineering quality, security, and production reliability remain your responsibility.
• You're curious about emerging AI technologies and interested in applying them to practical engineering challenges.

We're not looking for someone who simply generates code with AI. We're looking for an experienced engineer who knows how to use AI effectively while maintaining high engineering standards.

Nice to have

Experience with any of the following is an advantage:

• Model Context Protocol (MCP), including building remote MCP servers or AI connectors.
• OAuth 2.1, OpenID Connect, PKCE, and MCP authorization mechanisms such as CIMD or Dynamic Client Registration.
• GraphQL, gRPC, or advanced API integration patterns.
• Infrastructure as code, such as Terraform, and cloud deployment platforms.
• Agent frameworks, LLM APIs, or publishing AI integrations to public marketplaces.
• Optimizing infrastructure and AI-related costs.

You don't need to have worked with every technology listed. Strong fundamentals, practical experience, and a willingness to learn are what matter most.

What We offer

Flexible working environment

• Remote and/or office-based work
• Offices in Plovdiv and Veliko Tarnovo
• Standard working hours: 9:00 AM – 6:00 PM (Bulgarian time), with the option for a later start

Benefits and professional growth

• Additional health insurance
• Annual performance review and bonus
• Continuing education and professional development budget
• Corporate discounts
• Refer-a-friend program
• Baby bonus

Team and office culture

• Collaboration with experienced professionals and international teams
• Regular team-building events and celebrations
• Modern offices with game rooms
• Healthy office snacks

Our team and values

At VSG Bulgaria, we believe great software comes from strong engineering, shared knowledge, and people who take ownership of their work.

We encourage open communication, practical problem-solving, and continuous improvement. You'll work in a collaborative environment where your ideas and technical decisions matter.

Our values reflect how we work:

• Do the Right Thing - Act with integrity and take responsibility.
• Do Whatever It Takes - Approach challenges with determination and a focus on results.
• Have Fun! - Enjoy the work, support each other, and celebrate success.

Our mission is to make software development more efficient and accessible, enabling businesses to turn ambitious ideas into reliable products and services.

Ready to join us?

If you're an experienced engineer who enjoys solving challenging problems, takes pride in building reliable software, and believes AI can fundamentally improve how we develop it, we'd love to hear from you.

Don't meet every requirement? If you bring strong engineering experience, hands-on AI development skills, and the right mindset, we still encourage you to apply.

Please send your CV in English. All applications will be handled confidentially.

Questions about the role or application process?

Our People Team will be happy to help:

• Vaska Sivkova - Senior Talent & Brand Partner
• Mariyana Brogniart - HR Manager

Let's build better software, together.