Top Software Engineer Jobs in Madrid

Maintain and evolve FAdmin, a mission-critical Ruby on Rails flyer processing system, and related Content Platform tools. Deliver roadmap features end to end, support service desk requests, use AI coding agents to improve delivery and code quality, write automated tests, participate in code reviews, and maintain CI/CD pipelines. The role requires production software development experience, relational database and SQL expertise, and strong English communication.

Build and operate full-stack systems for an AI-powered offensive security platform. Responsibilities include developing React frontends, TypeScript APIs, Kotlin and Go backend services, deploying on AWS, designing scalable systems, optimizing databases, supporting production, and owning features from concept through deployment. The role involves close collaboration with AI and security researchers in a fast-paced remote startup.

Build and improve reliable, user-focused product experiences across the frontend and backend. Partner with Product, Design, and Engineering to understand user needs, propose solutions, implement features, troubleshoot software, write documentation, and contribute to technical and product decisions. Develop tested JavaScript or TypeScript code using React, Node.js, and related technologies while continuously learning and taking ownership of increasingly complex problems.

Develop and maintain Elasticsearch’s Inference API and plugin framework, integrating internal and external machine learning providers. Responsibilities include API and protocol design, streaming, asynchronous execution, rate limiting, billing integration, provider configuration, testing, open-source contribution reviews, and incident on-call support. The role requires advanced Java expertise, concurrency knowledge, API design skills, and collaboration across distributed engineering teams.

Own the design, development, and delivery of complex ERP features, backend services, APIs, data models, and user-facing functionality. Ensure reliability, performance, data integrity, and maintainability across production systems. Collaborate with Product and engineering teams, lead incident resolution, conduct code reviews, improve testing and monitoring, and mentor intermediate developers. Contribute to architecture, technical planning, hiring, and safe deployment practices including feature flags, incremental rollouts, and data migrations.

Design, develop, and maintain high-scale software services and microservices. Solve complex technical problems from architecture through production, build and consume RESTful APIs, work with event streaming and relational databases, and deliver reliable code through CI/CD. The role also includes system ownership, performance improvement, code reviews, architecture sessions, pair programming, mentoring, and collaboration in an agile engineering environment.

Design, build, and deploy production-grade agentic AI systems: multi-agent orchestration, RAG pipelines, provider integration, LLMOps, observability, and reusable patterns. Embed with client teams, lead design sessions, tune embeddings/vector search, manage cost/latency tradeoffs, and define metrics for accuracy, safety, latency, and cost.

Own the architecture and long-term direction of Alpaca’s Redpanda-based event streaming platform. Lead migration to event-driven systems, design scalable real-time client streaming, establish schema and library standards, shape authentication for streaming, partner on resilience and testing, mentor engineers, influence cross-team technical decisions, and participate in platform on-call. The role primarily uses Go and involves Kubernetes, Helm, PostgreSQL, observability, and distributed systems.

Maintain and evolve the Storybook codebase, designing APIs for developers, addon authors, and maintainers. Responsibilities include issue triage, pull request reviews, RFC development, educational content, community engagement, cross-team collaboration, and support rotation participation. The role requires strong web development experience, knowledge of frontend frameworks and build tools, excellent communication, and enthusiasm for improving developer experience and AI-assisted development workflows.

Build and operate production custody systems: signing service, key management, chain integrations, and transaction pipelines. Own end-to-end subsystems, integrate new chains, collaborate with cryptography on threshold signing and key recovery, write post-mortems, and produce clear async design docs and PRs.

The Senior Software Engineer will design and implement systems for AI integration, build scalable backend services, and mentor team members, ensuring high-quality systems that meet user needs.

Build AI-powered automation agents and modernize legacy enterprise systems for SME clients. Responsibilities include developing Python backends, integrating Salesforce, SAP, and Microsoft Dynamics, cleaning and transforming messy data, and delivering outputs through Power BI, PDFs, and APIs. The role involves working with LLMs, agent frameworks, and AI coding tools while collaborating with Spanish- and English-speaking clients in a fully remote consultancy environment.

Build and scale backend systems for AI-native construction procurement software. Own data models, GraphQL APIs, distributed processing semantics, integrations with construction ERPs, authorization, approvals, and transactional business workflows. Develop in Go with Postgres and AWS, while contributing to AI-driven document extraction, optimization, observability, and complex integrations. Collaborate in a fast-moving startup environment with evolving product requirements and strong ownership expectations.

Build core components of a diagnostic and personalization platform: backend data pipelines, frontends, services for genomic data ingestion, ML model integration, APIs, and cloud infrastructure. Collaborate with product and ML teams, iterate on prototypes and MVPs, and make architectural decisions supporting scalability and reliability.

Design and build the on-prem software stack for ModelVault appliances: containerized inference engines, model integration (LLMs/vision), deployment tooling, CLIs/GUI/APIs, OS and GPU setup, remote updates, telemetry, and collaborate with customers and founding team to iterate and scale the engineering org.

Build and maintain developer tools across SDKs, React Email, CLI, MCP, integrations, and supporting backend services. Collaborate on APIs, compatibility, testing, releases, documentation, and shared tooling. Support developers through GitHub issues and pull requests while designing reliable interfaces, error handling, and backward-compatible experiences. The role also involves operating systems with authentication, retries, rate limits, queues, monitoring, and error recovery.

Build and ship native Android features for an AI Neobank using Kotlin. Design clean user journeys for financial services, integrate backend APIs, improve performance and reliability, use analytics to iterate, and implement on-device AI where it improves UX.

Provides technical leadership for Elastic UI, a React and TypeScript design system used across Elastic products. Owns component architecture, APIs, theming, accessibility, versioning, migrations, performance, and long-term maintainability. Partners with design and engineering teams, drives adoption, mentors engineers, leads architectural decisions, and improves developer experience. The role also explores AI-assisted design-to-code, accessibility, and migration workflows while maintaining high quality standards.

Build and scale healthcare insurance products across claims management, insurance offers, and customer enablement. Design reliable systems, collaborate across teams, contribute to product decisions, mentor engineers, lead complex projects, and support hiring. Work with Python, JavaScript, React, React Native, PostgreSQL, and related web technologies in a product-focused engineering environment.

Designs, builds, deploys, and operates software, developer tooling, CI/CD systems, workflow automation, and cloud infrastructure supporting Firefox engineering. The role owns complex reliability, performance, observability, and cost-efficiency problems; uses telemetry and metrics for technical decisions; collaborates across engineering and IT; contributes to architecture, technical strategy, open-source projects, and AI-assisted development tools.

Develop privacy, anti-tracking, and phishing protections for Firefox and improve the Gecko browser engine. Build performant, low-latency, maintainable software in C++, JavaScript, and Rust while collaborating asynchronously with a distributed team. The role requires independently scoping and delivering complex features, with emphasis on memory safety, multithreaded architecture, data streams, web privacy, and browser security.

Design and deliver internal systems, Go services, APIs, data models, dashboards, visualizations, and LLM-powered workflow features. The role includes writing specifications, estimating work, code reviews, testing, documentation, security, performance, accessibility, and collaboration with nontechnical stakeholders. The engineer will handle sensitive people data, mentor colleagues, and improve team practices in a globally distributed environment.

Designs and scales real-time identity verification services, including APIs, event-driven systems, architecture, CI/CD, observability, and reliability foundations. The role owns technical architecture, raises engineering standards, mentors engineers, collaborates with ML and product teams, and delivers secure, maintainable, high-throughput services for internal and external customers.

Design, develop, and maintain high-quality web applications using CodeIgniter and PHP. Collaborate with cross-functional teams to define and ship features, ensure application performance and quality, identify and fix bugs, and maintain code quality and automation.

Builds software solutions for end users as a general full-stack engineer. The role emphasizes collaboration, ownership, accountability, fast-paced execution, adaptability, multitasking, rapid learning, and an ambitious, outcome-driven approach.