Senior Developer – High Throughput APIs
emagine · Portugal · remote
Role
We are looking for Senior Developers to join the engineering team, building and evolving our core financial processing platform. The products are backend services and APIs where performance, scalability, reliability, security, and correctness are fundamental requirements. The platform uses PHP and Java, and we are progressively migrating key components and services to Go.
The Senior Developer will be expected to operate at a very high technical level, be hands-on, writing production code and solving complex engineering problems while also contributing to architecture, system design, performance, security, and the evolution of the platform.
The role sits at the intersection of payments and online betting: candidates must bring hands-on experience in the online betting industry and be fully bilingual in English and French.
Responsibilities
• Design and develop highly scalable backend services and B2B APIs.
• Build and maintain systems capable of handling very high transaction volumes.
• Take ownership of complex technical problems from design through production.
• Design APIs, services, data models, and distributed systems with scalability and reliability in mind.
• Write clean, maintainable, testable, and production-ready code.
• Work extensively with databases and SQL, including query optimization and indexing.
• Identify and resolve performance bottlenecks at the application, database, and system levels.
• Design asynchronous processing and concurrent workloads using appropriate patterns.
• Contribute to the migration and modernization of PHP and Java modules toward Go.
• Design systems that are resilient to failures, including appropriate retry, recovery, and dead-letter mechanisms.
• Build strong observability through structured logging, metrics, tracing, and production monitoring.
• Apply security principles throughout the design and implementation of the APIs and services.
• Contribute to automated testing, CI/CD, containerization, and production deployment.
• Review code and technical designs and provide meaningful feedback to other developers.
• Integrate and maintain connections with payment providers and partners (card schemes, mobile money, bank gateways, wallets).
• Support real-time money flows specific to online betting, such as deposits, withdrawals, wallet balance updates, and payouts, with full accuracy and traceability.
• Collaborate with English- and French-speaking teams, partners, and stakeholders.
Key Requirements
• Proven senior-level backend development experience (typically 7+ years), including significant work on high-volume transactional systems.
• Strong production experience with PHP, Laravel, and Java, Spring Boot; hands-on experience with Go, or a strong commitment to adopting it quickly.
• Demonstrated experience in the online betting industry.
• Bilingual English and French, with the ability to work, write documentation, and communicate with partners in both languages.
• Advanced SQL and relational database skills, including query tuning and index design.
• Experience designing, building, and integrating payment APIs, wallets, or other financial transaction systems.
• Solid understanding of concurrency, asynchronous processing, and algorithmic complexity.
• Practical experience with Docker, CI/CD, and AWS.
• Degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience.
Nice to Have
• Experience with PCI DSS certification or recertification processes.
• Knowledge of betting-industry regulatory requirements.
• Familiarity with mobile money ecosystems and payment providers in West and Central Africa.
• Experience with Kubernetes, Ansible, or other infrastructure-as-code tools.
Other Details
• This role offers the opportunity to work in a fast-paced environment focusing on high-throughput financial infrastructure while being part of a bilingual team.