Remote Backend Developer jobs open to Spain.

Go

Shipped LLM/agent features to 10k+ users, Golang backend, RAG and tool calling, LLM evals, 1 year Web3 preferred

Trust WalletTrust Wallet is a leading B2C multi-chain, non-custodial cryptocurrency wallet enabling users to manage over 10 million digital assets, headquartered remotely with a global user base.

Python

Python, End-to-end ownership, Client-facing communication, Full-stack development, Cloud infrastructure, AI-powered development, Production-minded development, Business thinking, Self-management, Timezone flexibility

AE StudioAE Studio is a custom software development and design agency specializing in AI integration and data science, operating as a B2B provider for clients ranging from startups to Fortune 10 companies.

TypeScript · JavaScript · Node.js

5 years of experience, JavaScript, TypeScript, Node.js, AWS, AI application patterns, LLM-powered features, AI observability, Production AWS, REST/API design, Ownership mindset, English B2

WildixWildix is a Tallinn-based B2B UCaaS provider specializing in AI-powered VoIP and collaboration solutions for businesses across 135+ countries.

5+ years backend/AI systems, LLM inference, APIs/distributed systems; also eligible in Cyprus and Hungary

KrakenKraken is a financial platform where individuals and institutions trade crypto, stocks, ETFs, and futures.

AWS · Azure

2 years of experience, MuleSoft Anypoint Platform, API design, Integration Design patterns, Microservices architecture, Public cloud experience (AWS/Azure), Non-profit sector experience, Excellent debugging skills, Strong communication skills

fusionSpanfusionSpan is a Rockville, MD-based B2B technology consulting firm specializing in Salesforce implementations and managed services for nonprofits and membership organizations.

Unity, AI focus, Social gaming

Java · AWS

4 years of experience, Java, Spring Boot, RESTful APIs, Microservices, Distributed systems, Asynchronous processing, PostgreSQL, Redis, Kafka, AWS, High throughput systems, Idempotent transaction processing

Java · AWS

7 years of experience, Java, Spring Boot, RESTful APIs, Microservices, High-throughput systems, Idempotent transaction-processing, AWS, Kafka, Redis, Distributed systems

Go · Rust

Distributed databases/query engines, Golang or C++ or Rust, multi-tenant SaaS, in-person onboarding

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Go · Rust

Distributed databases/query engines, Golang or C++ or Rust, multi-tenant SaaS, in-person onboarding

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Go · Rust

Distributed databases/query engines, Golang or C++ or Rust, multi-tenant SaaS, in-person onboarding

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Python

~1 year production software engineering, Python, European work authorization, B2B contract, 40+ hours/week

KalepaKalepa builds AI-powered underwriting software that helps commercial insurers assess risks and manage decisions from submission through portfolio management.

Go · Rust

Distributed databases/query engines, Golang or C++ or Rust, multi-tenant SaaS, in-person onboarding

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Python · SQL

Python, Linux troubleshooting, API design and integration, Asynchronous processing, CI/CD, SQL, AI coding agents, Django, Django REST Framework, Celery, RabbitMQ

Java

5+ years backend, Java, Spring Boot, card issuing/payments, out-of-hours on-call

BVNKBVNK is a UK-based fintech B2B platform specializing in stablecoin payment infrastructure, enabling businesses to send, receive, and convert currencies globally.

Go · Rust

Distributed database/query engines, Golang/C++/Rust, catalogs and table formats, AI data systems

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Production-grade software, AI technologies, LLMs, Prompt engineering, Cloud-native environments, Observability tools, Multi-tenant architecture, Context management systems, Scalable SaaS solutions

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Production-grade software, AI technologies, LLMs, Prompt engineering, Cloud-native environments, Observability tools, Multi-tenant architecture, Context management systems, Scalable SaaS solutions

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Production-grade software systems, AI technologies, LLMs, Prompt engineering, Cloud-native environments, Observability tools, Multi-tenant architecture, Context management systems, Scalable SaaS solutions

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Production-grade software, AI technologies, LLMs, Prompt engineering, Cloud-native environments, Observability tools, Multi-tenant architecture, Context management systems, Scalable SaaS solutions

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

Production-grade software systems, AI experience, LLMs, Prompt engineering, Cloud-native environments, Observability tools, Multi-tenant architecture, Context management systems

Grafana LabsGrafana Labs builds Grafana Cloud and develops open-source observability projects including Grafana, Loki, Tempo, and Mimir.

3 years of experience, LLMs, CUDA-X APIs, API design, High-quality code, AI-assisted software engineering, Code generation, Programming language design

NVIDIANVIDIA builds accelerated-computing platforms for AI, data centers, gaming, robotics and autonomous vehicles.

Python

Enterprise SaaS administration (1,000+ seats), Python or comparable language, Integrating LLM and SaaS APIs, Identity and access management (Okta, OAuth, SCIM, SSO), Operational discipline (intake queues, SLAs), Teaching ability for technical concepts, Clear written communication for documentation, Judgment on capability needs

KrakenKraken is a financial platform where individuals and institutions trade crypto, stocks, ETFs, and futures.

Python · Rust · Ruby

Linux build toolchains, Container images, Debian/RHEL packaging, Continuous integration systems, Shell scripting, Cloud provider experience, Ruby/Go/Python/Rust

GitLabGitLab provides a DevSecOps platform for planning, building, securing and delivering software.

GraphQL

7 years of experience, Agentic systems, Durable execution engine, Multi-tenant platforms, Third-party API integration, Security control planes, PostgreSQL and Neo4j, GraphQL backends, Observability tooling, Prompt injection awareness

Horizon3 AIHorizon3.ai is a remote cybersecurity company specializing in the NodeZero autonomous pentesting SaaS platform, serving global enterprises and federal agencies in the B2B sector.

Python · Kotlin · Rust

Go, Kotlin, Rust, Python, SQL, Orchestration systems, Data lifecycle management, Schema evolution, Data correctness, Stateful stream processing, Distributed systems, AI tools proficiency, Clear written communication

DuneDune is a remote-first B2B SaaS platform specializing in multi-chain crypto data analytics, empowering developers and investors with insights into blockchain ecosystems.

JavaScript · PHP · SQL

PHP 8, Laravel, JavaScript, CSS, HTML, Debugging, Incident response, Root-cause analysis, Relational databases, SQL, Git, CI/CD, Autonomous work, Professional English (B2+)

Intel 471Intel 471 is a Wilmington, DE-based B2B cybersecurity company specializing in SaaS-based cyber threat intelligence solutions for enterprises and government agencies worldwide.

GCP · Kubernetes

Go, Kubernetes, Large-scale backend development, Microservices architecture, Performance analysis, Security product architecture, GCP services, Distributed systems optimization, API integration with SaaS applications

CyberhavenCyberhaven provides an AI-native data security platform for protecting data across human and AI-agent workflows.

SQL

Database performance optimization, Strong SQL, Backend engineering, Data architecture design, Lakehouse experience, Schema design for semi-structured data, Streaming ingestion experience, Migration or re-architecture track record

OscilarOscilar is a US-based fintech B2B SaaS provider specializing in AI-native risk decisioning for fraud prevention, credit underwriting, and AML compliance, serving banks and digital organizations.

JavaScript · Python · GCP

5 years of experience, Cloud-native technologies (GCP preferred), Kubernetes, ArgoCD, Terraform, GitHub, Python, JavaScript, Go, Technical leadership, Internal Developer Platforms, Cost optimization

MozillaMozilla is a family of mission-driven organizations behind Firefox, Thunderbird, open-source AI tools and public-interest technology initiatives.