26,991 Backend jobs
Server-side engineering roles — APIs, services, databases and backend systems.
Backend Engineer - Data Acquisition
Backend engineer on Lighthouse's Crawler Engineering team builds high-performance data acquisition systems—mostly in Rust—that collect hotel rates and supply data from ~200 million web requests a day, working on in-house proxy layers, browser tooling, and protocol-level debugging on Google Cloud/Kubernetes.
Backend Go Developer
Backend Go Developer at Gainrep (part of Alkemy Group, a Madrid-based digital consultancy) designing, building, and maintaining Go microservices and RESTful APIs. Day to day involves integrating services with frontend teams, debugging production issues, writing tests, doing code reviews, and joining Agile sprint planning.
Backend Developer (Kotlin/Spring Boot)
On-site backend developer in Huelva, Spain, building and maintaining robust, scalable enterprise applications with Java and Spring Boot in an agile team. Day to day: designing secure RESTful APIs, working with PostgreSQL/MySQL via Hibernate, code reviews, testing, deployment, and performance tuning.
Backend Developer | Java / Python | Banking
Contract senior software engineer role via Mercor: evaluates and enhances AI model capabilities on complex software-engineering tasks, builds benchmarks, and helps AI research labs improve training data quality. Fully remote, ~20 hours/week, paid $150–$210/hour via Stripe Connect.
PHP backend developer in adtech
PHP backend developer on Tappx's SSP Tech team in adtech: designs, builds, and maintains high-scalability SSP platforms and internal tools, owning the full lifecycle from technical design through production deployment and monitoring. Core stack is PHP with MySQL, plus API integrations, frontend basics, automated tests, and CI/CD.
Cloud Native Backend Developer
Backend developer building cloud-based business systems for an e-commerce customer: designing technical architecture with the product owner and implementing Java/Kotlin Spring Boot services with a DevOps stack of AWS, Terraform, Docker and GitLab CI/CD. Hybrid role in Valencia working with German colleagues.
Backend Developer (C.NET)
Backend developer building custom integrations in C#/.NET that connect third-party systems with SKIDATA's access solutions — owning projects from design through testing and documentation, working with APIs like REST, SOAP, gRPC and RabbitMQ, and supporting integration partners. Based in Madrid (hybrid).
Senior Backend Developer
Senior Backend Engineer for an AI-native SaaS platform near Barcelona: designing and scaling distributed, high-availability backend services with Django/Python and PostgreSQL, integrating external APIs, and strengthening observability, testing, CI/CD and team engineering standards. Hybrid role with 2 required office days per week.
Cloud Native Backend Developer
Backend developer (5+ years Java/Kotlin) building and operating cloud-native business systems for an e-commerce customer at Otto Group's tech consultancy. Day to day: system design and architecture with the product owner, Spring Boot REST/event-driven services, and DevOps with Terraform, Docker, GitLab CI/CD and AWS.
Java backend developer
K-LAGAN is hiring a Java backend developer in Barcelona to work on international logistics and intralogistics automation projects, building and integrating WMS/WCS solutions. Day-to-day work involves Java 17 and Spring Boot services, REST APIs, Oracle/SQL databases, and testing with JUnit/Mockito, with travel to project sites for commissioning.
Backend Developer In Healthtech
Senior backend developer at Biorce's Barcelona hub building and owning core backend services for Leadro, an AI-powered drug-development platform — data models, APIs, GTM integrations, and LLM/agentic features. Core stack: Node.js/NestJS, TypeScript, PostgreSQL/BigQuery, and GCP, in a hybrid work model.
PHP Backend Developer
PHP Backend Developer at Tappx, an AdTech firm in Spain: design, build, and maintain highly scalable SSP products and internal PHP tools, owning the full system lifecycle from design to production monitoring. Works with PHP, MySQL, NoSQL/Redis, CI/CD, and AI tools; hybrid in Barcelona/Madrid or 100% remote within Spain.
Desarrollador/a Java Backend - Digital Cards & Payments
Freelance (autónomo) Java backend developer for a banking-sector project on digital cards, tokenization, wallets and payment methods. Builds and evolves microservices with Java 11+, Spring Boot and Kafka/RabbitMQ; 100% remote, 1-year contract with possible extensions; Spanish C1 required.
Desarrollador Backend Senior (Hidrocarburos Remoto)
Fully remote senior backend developer role serving a client in the hydrocarbons/energy sector via recruiter Placements24: designing scalable APIs and microservices, managing databases, and running cloud/containerized systems. Stack includes Python/Java/Go/Node.js, PostgreSQL/MySQL/MongoDB, AWS/Azure/GCP, and Docker/Kubernetes.
Desarrollador/A Backend Senior
Senior backend developer (with project-manager duties) at a family-safety smartwatch company: designs, builds and maintains Node.js APIs and services backed by PostgreSQL, integrates RabbitMQ messaging, writes unit/integration tests, and works in agile Scrum/Kanban workflows; Docker, AWS and Jenkins CI/CD experience valued.
Desarrollador Backend Java - Microservicios Sector Público
Senior backend developer building scalable web applications and RESTful APIs with Python and Django (incl. Django Rest Framework) for a tech startup, working fully remotely from Madrid. Focus on performance tuning, code reviews, and production debugging; note the posting title mentions Java/public sector but the description describes a Python/Django role.
Senior AI-Driven Backend Engineer (Remote)
Senior individual-contributor backend engineer at Toronto-based, remote-first Makeitfable, building and scaling customer-facing AI-powered applications and agentic workflows. Works with Product, Design, and SRE, with periodic in-person meetings in the Greater Toronto Area.
Senior Backend Engineer - AI & Real-Time Systems (Remote)
Back-end engineer on Superhuman's Mail team building and running production services for AI-driven workflows, calendar syncing, and real-time APIs used across desktop, web, and mobile. Core stack: Go, Postgres, Kubernetes, and AWS.