Senior Python Engineer

FIRST. is a dynamic and innovative global technology company that provides B2B SaaS solutions for online sports platforms. We are at the forefront of innovation, empowering gaming partners with revolutionary sportsbook solutions. Our cutting-edge sportsbook software, premium data feeds, and unwavering commitment to partner success are reinventing the gaming industry.

About the role

We are looking for a Senior Python Engineer to join a new team that builds a new product from scratch. A modern, API-driven platform designed around performance, scalability, and seamless integrations. This candidate will join a small, high-impact engineering team working in a fast-paced startup environment, where autonomy, agility, and creative problem-solving are required. You will work closely with our product, backend and frontend teams to design and implement microservices, API integrations, and event-driven components, contributing directly to the foundation of a scalable system architecture.

Responsibilities:

• Design and develop backend microservices using Python (FastAPI, asyncio, etc).
• Implement RESTful and streaming APIs with strong focus on performance and reliability.
• Contribute to event-driven architectures (e.g., Kafka, RabbitMQ, Redis Streams, or Celery-based systems).
• Integrate with third-party APIs and services, handling authentication, error recovery, and data normalization.
• Design and optimize database schemas, migrations, and ORM layers.
• Collaborate on CI/CD pipelines, containerized deployments, and environment management.
• Drive continuous improvement in code quality, performance, and developer experience.
• Participate in architecture discussions, code reviews, and system design sessions.

Requirements:

• Strong proficiency in Python with practical experience in FastAPI, asyncio, and typing. Flask, Django experience as a plus.
• Experience designing and maintaining microservice architectures.
• Solid understanding of databases and migration tools (Alembic, Django Migrations, etc.).
• Experience with message brokers / event-driven systems (RabbitMQ, Kafka, Redis Pub/Sub).
• Familiarity with Docker, CI/CD pipelines (GitLab CI, GitHub Actions, etc.).
• Experience integrating external APIs (OAuth2, webhooks, streaming endpoints, REST).
• Knowledge of testing frameworks (pytest, unittest) and observability (logging, tracing, metrics).

Preferred:

• Strong architectural mindset — ability to design systems that scale.
• Experience mentoring developers and leading technical decisions.
• Exposure to cloud environments (DigitalOcean, AWS, GCP).
• Familiarity with async event loops, background tasks, and real-time applications (WebSockets).

We offer:

• An open-minded environment that values you
• An international multicultural team
• An amazing office environment (table tennis, play station, all the fun stuff)
• Food vouchers (180 BGN)
• Additional health insurance
• Sports card
• 21 days paid leave
• Flexible working hours
• Manicure, barber, massage, breakfast, and snacks in the office
• Wedding and new baby bonus
• Тeam building activities

If you are interested in joining our diverse and dynamic team, we are looking forward to your application. Only short-listed candidates will be contacted. Confidentiality of all applications is assured!

By submitting your application, you explicitly consent, in accordance with Regulation (EU) 2016/679 (General Data Protection Regulation), to the processing of the personal data contained in your CV, resume, and/or motivational letter strictly for the purposes of the recruitment and selection process conducted by the Company. By applying to this job offer, you also freely and expressly consent to the Company storing your personal data and considering your application for future employment opportunities, in accordance with the Company’s data retention policy and applicable legal requirements. You may withdraw your consent to the processing and/or storage of your personal data at any time, without affecting the lawfulness of processing based on consent before its withdrawal, by contacting sending an email request to the following address: dpo@first.bet

Why we need to process your personal data for another term:

• to be able to contact you when we have a suitable position that matches your profile;
• to be able to send you job offers which might be interested for you;
• to contact you directly, without needing you to go again through the whole selection procedure.

What we will continue to store for you?

• Your name, email, telephone number, social media profile link/s, picture from your CV;
• Your professional experience;
• Your skills, language proficiency, special info from your CV, sent by you.