Senior Software Engineer (Golang)

We are expanding our Tech team with a Senior Software Engineer based onsite in our office in Barcelona!

As a Senior Software Engineer, you will design, build, and operate the backend systems that power Fast Track’s platform. Our infrastructure runs on AWS, orchestrated with Kubernetes (EKS) and Docker, and leverages services such as, and Cloudflare for edge delivery and serverless workloads. Data is managed across MySQL, Amazon RDS Aurora, ClickHouse for analytics, and in-memory stores, including Amazon ElastiCache and MemoryDB. Observability is driven by Prometheus and Grafana, with OpenTelemetry being assessed as a future standard.

To be successful in the role, you will need a strong product mindset and enjoy working closely with real customers, and care deeply about building systems that last.

Your responsibilities as a Senior Software Engineer at Fast Track would include:

Build and Improve Backend Systems

• Design and develop backend services and APIs that power the Fast Track platform

• Build scalable, reusable frameworks and shared libraries that accelerate delivery across teams

• Refactor existing solutions to reduce duplication, fragility, and operational overhead

• Contribute to improving observability (logging, metrics, alerts), so issues surface early

Product-Oriented Engineering

• Treat integrations as part of the product, not just technical glue

• Understand partner use cases and constraints with support from senior engineers

• Help balance short-term delivery with longer-term maintainability

• Ask “why” and propose improvements when current solutions don’t scale

Quality, Security and Reliability

• Write testable, maintainable code with appropriate unit and integration tests

• Ensure features are production-ready before handoff, meeting quality, security, and reliability standards.

• Lead incident response within the owned domain, drive root cause analysis, and embed systemic improvements into engineering practices

• Keep documentation for owned systems accurate and up to date

Collaboration and Growth

• Collaborate closely with Product, Tech Leads, and peers

• Actively participate in code reviews and design discussions

• Learn and apply best practices in system design, performance, and reliability

Emerging Tech-Aware Mindset

• Be curious and proactive about how emerging technologies can improve productivity, code quality, and decision-making

• Use emerging technologies as a multiplier: faster exploration, better debugging, clearer documentation

• Focus your human effort on what matters most: system design, product thinking, trade-offs, and ownership

• Stay grounded: understanding where emerging technologies help and where engineering judgment still matters most

• Extensive experience in backend development, working with complex production-grade systems

• Proven ability to design, build, and evolve high-performance microservices in high-traffic environments

• Strong experience designing scalable APIs and distributed systems, with clear separation of concerns

• Demonstrated expertise in building testable, high-quality code, including unit, integration, and load testing

• Strong understanding of systemic code and architecture quality, with the ability to identify and resolve cross-area issues

• Proven experience establishing and driving testing best practices, automation, and a continuous testing culture

• Ability to lead and review complex pull requests, providing forward-looking architectural feedback and mentoring other engineers

• Experience in defining and enforcing coding guidelines and quality standards, raising the bar across the team

• Strong system design skills, including leading design discussions, articulating trade-offs, and making sound technical decisions under constraints

• Ability to balance short-term delivery with long-term architectural health, breaking down large initiatives into incremental deliverables

• Experience in anticipating technical and delivery risks and defining mitigation strategies

• Hands-on experience contributing to or leading incident response, ensuring learnings are embedded into engineering and delivery practices

• Strong collaboration skills, including working closely with Product and UX to prioritise and validate early iterations.

Nice to Have:

• Previous experience with Golang

• Experience working in highly regulated or performance-critical domains

• Proven ability to influence architecture across multiple teams or domains

• Experience formalising observability standards (metrics, logging, alerting)

• Track record of translating industry trends or new technologies into practical, team-level improvements

Development at Fast Track

At Fast Track, we provide a dynamic environment for high-performance individuals who are ready to elevate their skills. Our tech stack is cutting-edge and constantly evolving. We utilise continuous integration and deployment with GitHub Actions, incorporating relevant workflows and approval processes. Our code runs on Docker with Kubernetes orchestration, and all our infrastructure is managed with Terraform, embracing infrastructure as code principles. We leverage Kafka and RabbitMQ for our queue systems and ClickHouse for data storage, complemented by advanced monitoring through Grafana. Our microservice architecture is designed for optimal performance and scalability. To further digitalise our development efforts and optimise efficiency, we have developed internal build servers and monitoring tools to ensure reliability and continuous improvement.

Working at Fast Track

Fast Track is a disruptive technology company, recognised as the iGaming industry CRM leader. Fast Track provides a new way of working, enabling teams to focus on innovation and growth. We are a tight unit with a strong culture and our leadership in tech and the product has attracted high-performance individuals. Fast Track works with hundreds of companies worldwide, with offices in Malta, Sweden, Spain, and the United States, and has been certified as a Great Place To Work®️

Perks and Benefits of Working at Fast Track in Barcelona, Spain

• Great Place to Work® Certified – Officially recognised for our commitment to building an engaging high-trust culture.

• Collaborative Onsite Work Environment – Be part of a dynamic, innovation-driven team in an open, inspiring workspace.

• Central Barcelona Office – Work in the heart of the city, close to top attractions, culture, and Mediterranean beaches.

• Be part of our yearly Growth Summit – Join our global team for an inspiring event to connect, collaborate, and celebrate together.

• 25 paid vacation days - Extra time off to disconnect and recharge

• Wellbeing Benefit – We sponsor your well-being activities such as gym memberships or fitness classes to support your health.

• Mental Wellbeing– 24/7 access to mental health support.

• Private Health Insurance – Comprehensive coverage for you through AXA.

• Top-of-the-line Equipment – Best-in-class MacBooks and all the tools you need to excel.

• Breakfast Every Day – Start your morning with a complimentary, healthy breakfast at the office.