Senior Python Developer, Banking App

Join the best bank to work for in Bulgaria*

Who we are:
Do you want to join a well-established bank with a start-up culture? No, we’re not joking!

We, at tbi, have been one the most profitable banks for years and we are growing at a fast pace. We’re a bank with a long history of success that operates as a start-up and we’re always on the lookout for new opportunities to grow our business. How do we do that?

It's all about our people. Our team is made up of brave, passionate and caring people who don’t just want to follow the same path – we want to transform into mobile-first, state-of-the-art lifestyle ecosystem. Our colleagues love working here – 80% of them would recommend tbi as an employer to their friends and family. Our people are engaged in challenging and meaningful work, inspired to grow their potential and career, encouraged to learn and empowered to take decisions. That’s not corporate babble, it’s what our people say.

Do you want to play a key role in our unique success story?

If so, we're looking for a Senior Python Developer to join our team on the journey to success!

We are seeking an experienced Senior Middleware (MW) Python Developer with strong expertise in Python (3.11+) to design, build, and maintain scalable, high-performance middleware services using aiohttp. This role plays a key part in developing secure and reliable backend solutions for mobile banking platforms, with a strong focus on RESTful APIs, API versioning strategies (v1/v2), backward compatibility, and distributed systems.

As a senior member of the team, you will take technical ownership, contribute to architectural decisions, and collaborate closely with cross-functional teams across multiple repositories.

What You’ll do:

• Design, develop, and maintain backend and middleware services for mobile banking applications

• Take ownership of middleware components and contribute to system architecture and technical decisions

• Build scalable, reusable, and high-performance solutions using Python and asynchronous frameworks (aiohttp)

• Design, develop, and maintain RESTful APIs and microservices with proper versioning (v1/v2) and backward compatibility

• Ensure high availability, performance, and reliability in distributed systems

• Collaborate closely with cross-functional teams (Frontend, Product, Business Analysts, QA) to deliver high-quality solutions

• Actively participate in Agile ceremonies and provide technical leadership within the team

• Optimize backend processes, database queries, and overall system performance

• Troubleshoot complex production issues and drive root-cause analysis

• Ensure compliance with security standards, banking regulations, and internal policies

• Maintain clear, accurate, and up-to-date technical documentation

• Contribute to continuous improvement of architecture, development practices, and team workflows

• Mentor junior and mid-level developers when needed

Requirements

What you’ll need to succeed:

• Bachelor’s degree in Computer Science or a related technical field

• 5+ years of professional experience in Python development

• Strong hands-on experience with Python 3.11+ and asynchronous programming (aiohttp or similar frameworks)

• Solid understanding of RESTful API design, API versioning strategies, and backward compatibility

• Experience with Java, particularly Spring Boot, is a strong advantage

• Knowledge of reactive programming concepts (WebFlux), PostgreSQL, and R2DBC

• Proven experience building and deploying applications using Docker

• Strong experience in relational database design (MSSQL, MySQL, PostgreSQL, Oracle, or similar)

• Hands-on experience with Jira, Bitbucket, and GitLab

• Excellent understanding of Object-Oriented Programming (OOP) principles and design patterns

• Experience working in Agile/Scrum development environments

• English proficiency at B2 level or higher

• Strong problem-solving skills and the ability to work independently

• Proven ability to collaborate effectively and provide technical guidance within a team

  
  

What we offer:

• Seize the opportunity to grow your career

• Engage in exciting and meaningful work

• Get recognition for your work and attitude

• Become part of a large, friendly and supportive team with 16+ nationalities

• Get additional private health insurance

Visit our Career Page to learn more about what makes us different.

If this sounds like something you’d be interested in, we'd love to hear from you!

To apply for this position, please send us your CV in English.

We'd love to get back to everyone, but due to the number of applications we receive, we can only contact the shortlisted candidates.

*We are ranked the top bank and top 3 employer to work for in Bulgaria according to Kaderabotim.bg 2025 employer rankings.

All applications are treated with utmost confidentiality.

By submitting your job application to tbi bank, you confirm that you have read the document named “Information related to personal data processing for job applicants” publicly available on tbi Career page.