Evolution
Senior Backend Developer
- Location
- Sofia, Sofia City Province, Bulgaria
- Work model
- OnSite
- Seniority
- Senior
- Employment
- FullTime
- Posted
- Added to Codestelle
Language requirements
- German
- Not specified
- English alone
- Not specified
Based on explicit wording in the listing. “Not specified” does not mean a language is optional.
About this role
As a Senior Backend Developer in our Backend team, you will be a core technical contributor responsible for driving the architecture, scalability, and domain modeling of our high-concurrency Online Gaming & Betting Platform. Working alongside our Backend Architect and Engineering Lead, you will shape the future of our high-throughput platform, which processes real-time betting operations and high-volume financial transactions globally.
In this role, you will apply Domain-Driven Design (DDD) principles to model complex business domains into clean, maintainable, and decoupled microservices. You will lead technical design sessions, mentor junior and mid-level engineers, conduct rigorous code reviews, and drive performance optimizations across our RESTful API services, databases, and Docker-based environments.
Mission & Responsibilities
- Architect, design, and write high-performance, fault-tolerant PHP code utilizing Domain-Driven Design (DDD) and SOLID principles.
- Lead domain modeling discussions, define Bounded Contexts, and establish a Ubiquitous Language between technical and business domains.
- Maintain rigorous code review standards to enforce code quality, architectural consistency, and system security.
- Drive continuous performance tuning, database optimization, and refactoring of legacy components.
- Mentor and guide junior and mid-level developers, fostering continuous technical growth within the team.
- Partner with QA, DevOps, and Product leadership to ensure rapid, reliable deployment of critical backend services.
- Extensive hands-on experience in advanced PHP software development (PHP 7.4+, PHP 8.x).
- Practical experience applying Domain-Driven Design (DDD) concepts (e.g., Aggregates, Entities, Value Objects, Domain Events, Repositories, Bounded Contexts).
- Strong expertise in core PHP and custom architecture patterns without over-reliance on framework abstractions.
- Advanced experience with MySQL / MariaDB optimization, query tuning, indexing strategies, and handling heavy transaction loads.
- Deep knowledge of Docker, container orchestration, and modern containerized deployment strategies.
- Proven track record of designing, building, and maintaining high-throughput, low-latency RESTful APIs.
- Solid experience with JavaScript / Node.js for microservices or real-time event processing.
- Mastery of OOP principles, SOLID guidelines, design patterns, and clean code principles.
- Experience with automated testing, TDD/BDD practices (Codeception, PHPUnit).
Advantages:
- Experience with event-driven architectures and message brokers (RabbitMQ, Kafka).
- Expertise in caching layers (Redis, Memcached) and high-load database architecture (replication, sharding).
- Familiarity with web server administration and optimization (Nginx, Apache).
- Experience in the Online Gaming, FinTech, or high-frequency transactional domain.