CA

Backend Engineer

Calyptus euskadi Posted 26 Oct 2026 Closing: 25 Nov 2026
Permanent Hybrid

Role Description & Technical Scope

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The Role

We are seeking an experienced Backend Engineer who is excited to build the technical backbone of a new generation travel platform. You’ll work with Java and Spring Boot to design and implement scalable, resilient backend services, and use databases like MySQL, MongoDB, and ElasticSearch to power search, personalization, and booking flows. Familiarity with Linux systems, AWS, and microservices architecture will help you ship reliable systems at scale.

Core Responsibilities
  • Design, develop, and scale backend systems using Java and Spring Boot.
  • Create low-latency search infrastructure (ElasticSearch, caching, query optimization).
  • Build and maintain supplier integrations across hotels, chains, and experiences, ensuring stability and fault tolerance.
  • Implement real-time personalization and ranking logic to improve customer discovery and booking conversion.
  • Enable AI-powered experiences by building APIs, data pipelines, and scalable systems that support recommendations, personalization, and conversational interfaces.
  • Develop and maintain database schemas, queries, and stored procedures (MySQL, MongoDB, ElasticSearch).
  • Deploy and optimize services on Linux and AWS environments (EC2, S3, RDS, Lambda, API Gateway).
  • Implement and evolve microservices architecture; design APIs for communication between services.
  • Monitor backend systems in production, troubleshoot issues, and deliver timely fixes.
  • Collaborate with product, growth, and engineering peers to translate customer needs into backend solutions.
  • Participate in code reviews, debugging, and documentation to ensure quality and maintainability.
  • Stay current with new backend and AI technologies, bringing forward ideas for innovation and scale.
Candidate Requirements
  • Bachelor’s or Master’s degree in Computer Science, Software Engineering, or a related field.
  • 2–5 years of backend development experience with Java and Spring Boot.
  • Strong knowledge of relational and NoSQL databases (MySQL, MongoDB) and ability to design efficient schemas, queries, and stored procedures.
  • Familiarity with ElasticSearch and interest in building low-latency search systems.
  • Hands-on experience with Linux systems and deploying/maintaining backend services in production.
  • Experience with AWS services (EC2, S3, RDS, Lambda, API Gateway) and cloud-native deployments.
  • Understanding of microservices architecture and proven experience designing and implementing APIs for service communication.
  • Strong problem-solving and analytical skills with a focus on scalability, reliability, and performance.
  • Excitement to work in an AI-first company, building systems that power personalization, recommendations, and AI-driven experiences at scale.
  • Excellent communication skills and the ability to collaborate effectively across product, growth, and engineering teams.

Disclaimer: Calyptus uses an automated assessment tool that scores applicants.

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Key Details
  • Date Posted: 26 Oct 2026
  • Location: euskadi
  • Employment: Permanent
  • Workplace: Hybrid
  • Domain: General
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CA
Calyptus
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Enterprise technology firm or security consultancy operating across the UK digital defense ecosystem.

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