Senior Software Engineer (Backend) - Lingo

JOB DESCRIPTION: Senior Software Engineer (Backend) ABOUT LINGO Lingo is building a cutting‑edge digital health platform that fuses continuous biosensor data, high‑performance backend engineering, and advanced analytics to help people live healthier, longer, fuller lives. Our systems process massive volumes of real‑time data, and the backend is the heartbeat that transforms biosensor signals into actionable health insights for our users. THE OPPORTUNITY We’re seeking a Senior Software Engineer ( Backend ) to design, build, and optimize Lingo’s backend systems, ensuring they are scalable, resilient, and secure. You will play a pivotal role in implementing high‑performance APIs, event‑driven services, and data integrations across our global deployments. In this role, you’ll work closely with Product, Mobile, Platform/SRE, and Data/ML teams to deliver robust cloud‑native services, troubleshoot complex issues, and continuously improve reliability and developer experience. You’ll contribute your expertise to architecture discussions, lead implementation of key projects, and mentor junior engineers in best practices. WHAT YOU’LL DO Design, develop, and maintain scalable microservices and APIs for real‑time biosensor data processing. Implement event‑driven integrations with messaging/streaming systems (Kafka, RabbitMQ) and analytics pipelines. Collaborate with SRE to ensure observability, performance, and operational excellence across backend services. Participate in architecture and design reviews, contributing to decisions on service boundaries, data models, and communication patterns. Optimize backend services for low latency, high throughput, and cost efficiency. Apply privacy‑by‑design and security standards in line with HIPAA/GDPR compliance requirements. Write clean, maintainable, and testable code; establish and uphold engineering standards within the team. Mentor junior engineers through code reviews, pair programming, and knowledge sharing sessions. Troubleshoot production issues and contribute to incident response and post‑mortem analysis. REQUIRED QUALIFICATIONS 5-8 years of backend engineering experience with distributed, cloud‑native systems. Strong skills in microservices architecture and API design (REST; familiarity with GraphQL/gRPC is a plus). Experience with Kubernetes in production environments and familiarity with service mesh concepts. Hands‑on proficiency with messaging/streaming systems such as Kafka or RabbitMQ. Programming expertise in backend languages such as Java, Kotlin, Python. Knowledge of secure coding practices and compliance requirements (HIPAA, GDPR, or similar). Solid understanding of performance optimization, scalability patterns, and async data processing. Strong collaboration and communication skills; ability to work cross‑functionally with other engineering and product teams. PREFERRED QUALIFICATIONS Experience integrating backend services with analytics and machine learning pipelines. Exposure to API gateways, authentication/authorization patterns, and rate limiting strategies. Background in digital health, IoT, or other mission‑critical platforms. Familiarity with cloud platforms (Azure/AWS/GCP) and infrastructure‑as‑code tooling (Terraform, Helm). LINGO CULTURE Customer‑first, quality‑driven, growth‑minded, and united. As a Senior Backend Engineer, you’ll contribute directly to delivering secure, reliable, and scalable features, helping teams ship innovative health technology quickly and with confidence. The base pay for this position is N/A In specific locations, the pay range may vary from the range posted. JOB FAMILY: Product Development DIVISION: LNGO Lingo LOCATION: Spain > Barcelona : Av. Diagonal, 601 ADDITIONAL LOCATIONS: WORK SHIFT: Standard TRAVEL: No MEDICAL SURVEILLANCE: Not Applicable SIGNIFICANT WORK ACTIVITIES: Not Applicable