Senior Software Engineer

Sinch

. Design and build backend services supporting Chatlayer’s text and voice channels, including WebSocket servers and real-time communication infrastructure .

Posted 10/2/2026full-timeMadrid • SpainSenior💰 €70,000 - €90,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates strong proficiency in Node.js/TypeScript and Go, with extensive experience in building backend services and real-time communication infrastructure. Capable of leading technical discussions, mentoring engineers, and improving operational processes in a distributed team environment.

Highest-signal resume keywords

Node.js/TypeScript ProficiencyReal-Time Systems ExperienceMicroservices ArchitectureCloud Infrastructure ExperienceRESTful API Development

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Node.jsTypeScriptGoWebSocketKafkaMongoDBMicroservicesRESTful APIsCloud InfrastructureSystem Design

Soft Skills

Excellent CommunicationMentoringCollaboration

Tools & Technologies

GCPAWSDockerKubernetesOAuthOIDC

Industry Keywords

Conversational AIChatbotVoicebotNLPNLUCPaaS

Tech Stack

Tools & technologies

AWSCloudDistributed SystemsDockerGoogle Cloud PlatformJavaScriptKafkaKubernetesMicroservicesMongoDBNode.jsRedisTypeScriptGo

About the role

Key responsibilities & impact

Design and build backend services supporting Chatlayer’s text and voice channels, including WebSocket servers and real-time communication infrastructure
Work on platform integrations and app-integration frameworks
Contribute to architectural evolution by decoupling legacy dependencies and building modular, vendor-agnostic systems
Participate in technical decisions around SinchID, MongoDB Atlas, Kafka, Temporal, and new platform capabilities
Lead code reviews, technical discussions, and knowledge-sharing sessions
Mentor and be mentored by engineers and contribute to the engineering culture
Support production systems through on-call rotations and incident response
Improve test coverage, address technical debt, and continuously improve operational processes

Requirements

What you’ll need

5+ years of professional software engineering experience
Strong proficiency in Node.js/TypeScript and/or Go
Experience with real-time systems, including WebSocket or event-driven architectures
Hands-on experience with complex cloud infrastructure, ideally GCP and/or AWS
Experience with microservices architecture and distributed systems, including state management across replicas such as ETCD or Redis
Working knowledge of MongoDB or similar document databases
Experience building and maintaining RESTful APIs and event-driven architectures, ideally Kafka
Strong system design fundamentals, including scalability, latency, failover, and trade-offs
Excellent communication skills and comfort working in a distributed, cross-functional team
Corporate language is English; application must be submitted in English
Preferred: experience with conversational AI, chatbot or voicebot platforms, or NLP/NLU pipelines
Preferred: experience with Docker and Kubernetes
Preferred: familiarity with OAuth/OIDC identity management systems
Preferred: prior experience in a CPaaS, scale-up, or fast-growth product company