Senior Backend Engineer, Core APIs (SRE Focus)

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Backend Engineer, Core APIs (SRE Focus) based in Spain.

This is a senior engineering role focused on building and operating highly reliable backend systems at significant scale.

You’ll develop core APIs and real-time data services where performance, availability, latency, and cost are critical design considerations.

The role combines hands-on backend engineering with strong Site Reliability Engineering ownership in production.

You’ll define and monitor service objectives, improve observability, automate operational work, and help the platform scale safely as demand grows.

You’ll take ownership of systems throughout their lifecycle, from technical design and implementation through deployment, incident response, and continuous optimization.

Working within a fully remote, globally distributed team, you’ll collaborate asynchronously while contributing to engineering standards and mentoring other developers.

This is an opportunity to solve complex distributed-systems challenges while helping build technology that protects businesses and users from online fraud.

Accountabilities

• Design, develop, and optimize highly performant backend services for real-time data processing and web APIs, balancing reliability, latency, scalability, and infrastructure cost.
• Define and own SLIs, SLOs, and error budgets for core API services, using reliability data to guide engineering and delivery decisions.
• Build and maintain effective observability through meaningful metrics, structured logging, distributed tracing, dashboards, and actionable alerts.
• Participate in an equitable on-call rotation, respond effectively to production incidents, mitigate customer impact, and lead blameless post-incident reviews.
• Automate repetitive operational processes and follow through on incident action items to reduce operational toil and prevent recurring failures.
• Conduct capacity planning, load testing, performance analysis, and tuning to ensure systems can scale ahead of demand.
• Investigate complex production and product issues by developing hypotheses, running experiments, analyzing results, and translating findings into engineering improvements.
• Integrate backend components with other services and collaborate with cross-functional teams to maintain performance, scalability, and reliability across the platform.
• Contribute to a data-driven, reliability-focused engineering culture by sharing best practices and improving development and operational processes.
• Mentor other engineers and support the continued growth of technical skills, engineering judgment, and operational excellence across the team.

Requirements

• 5+ years of backend software engineering experience, including substantial experience operating production systems that you have helped build.
• Demonstrated experience with formal SRE practices, including error budgets, capacity planning, production readiness reviews, or fault-injection and resilience testing.
• Strong hands-on experience with Go and/or Node.js, with the flexibility and willingness to learn the other technology.
• Proven ability to design, develop, and maintain scalable backend systems, APIs, microservices, and real-time data-processing services.
• Practical experience running production workloads with Docker and Kubernetes or comparable containerization and orchestration technologies.
• Experience with infrastructure-as-code tools such as Terraform or AWS CloudFormation.
• Working knowledge of observability platforms such as Datadog, including service instrumentation, monitoring, logging, tracing, dashboards, and alerting.
• Experience participating in production on-call rotations, troubleshooting live incidents, mitigating impact, and conducting post-incident analysis.
• Strong SQL skills and experience working with databases or data stores such as DynamoDB, Redis, or Elasticsearch.
• Familiarity with Git, shell scripting, IDEs, CI/CD pipelines, and standard software engineering practices.
• Strong understanding of distributed systems, scalability, reliability, and performance engineering.
• Excellent English communication skills and the ability to collaborate effectively within a globally distributed, remote-first environment.
• Ability to work independently, take ownership of complex problems, and collaborate effectively across teams.
• Strong interest in mentoring engineers and helping raise technical standards across the organization.
• A degree in Computer Science or a related discipline is welcome but equivalent professional experience is also valued.
• Experience with analytical platforms such as ClickHouse, Snowflake, BigQuery, Redshift, or Databricks is an advantage.
• Experience with performance profiling and cost optimization for high-throughput cloud workloads is a plus.
• Experience contributing to large open-source projects and working asynchronously across international teams is beneficial.
• Experience with both Node.js and Go in backend environments, as well as knowledge of internet security and privacy mechanisms, is highly valued.

Benefits

• US compensation reference: $150,000-$200,000 in cash compensation for US-based employees; compensation ranges vary according to hiring location.
• Fully remote working environment with the ability to work from a wide range of countries, subject to local regulatory and security requirements.
• Opportunity to work on high-scale backend and fraud-detection infrastructure with meaningful reliability and performance challenges.
• Exposure to modern technologies including Go, Node.js, TypeScript, AWS, Terraform, Docker, Kubernetes, Datadog, ClickHouse, and dbt.
• Flexible, globally distributed work environment designed around remote collaboration and asynchronous communication.
• Opportunities for continuous technical development, experimentation, and knowledge sharing.
• Strong emphasis on engineering ownership, reliability, mentorship, and professional growth.
• Inclusive workplace that values diverse perspectives, experiences, and cultural backgrounds.
• Visa sponsorship is not provided; employees must be authorized to work from their home location.
• Country-specific employment requirements and compensation structures may apply outside the United States.