Top Software Engineer Jobs in Barcelona

Join a growing team as a Junior Java Software Engineer, designing and coding Java applications, participating in Agile development, and ensuring code quality through TDD.

Develop, test, integrate, and support robotic controls software for automated lift trucks in an embedded environment. Responsibilities include vehicle control communication, simulation, requirements development, software and electrical architecture, code and design reviews, supplier leadership, manufacturing support, and mentoring entry-level engineers. The role requires C/C++ development, robotics sensors and SLAM experience, embedded control systems, network communications, and MATLAB/Simulink/Stateflow expertise. Occasional travel may be required.

Lead design and delivery of real-time fraud decisioning services and APIs, extend decisioning platform to international markets, integrate regional risk vendors and ML/AI signals, own platform tooling and availability, mentor engineers, collaborate cross-functionally, and participate in on-call rotation.

Design and implement features for scalable games, ensuring quality, performance, and security, while collaborating in an agile environment.

Design and build scalable backend services using Node.js and MongoDB. Collaborate with teams for technical solutions, and ensure reliable architecture with clean code.

Develop and maintain sophisticated automated tests across integration, component, UI, load, and distributed systems. Build test harnesses and infrastructure, analyze and triage results, debug production and development issues, and establish quality metrics. Collaborate with engineers, product owners, and analytics teams on testability and requirements. Mentor junior staff, guide automation strategy, reduce technical debt, and influence technical decisions across projects and teams.

Design and scale mission-critical market data services for stocks, options, crypto, and foreign exchange. Responsibilities include architecting backend systems and APIs, maintaining software quality and test coverage, participating in code reviews, and troubleshooting incidents and bugs. The role uses Go and Python with REST, gRPC, WebSockets, SSE, Docker, Kubernetes, Google Cloud, BigTable, Prometheus, Grafana, and ELK.

Design and build durable, distributed data-streaming infrastructure that decouples process data from Camunda’s live execution engine. Develop customer-facing integrations such as Kafka connectivity, support analytics data consumption at scale, and make architecture decisions around consistency, durability, and storage. Participate in production support and on-call rotations while collaborating with Product, Data Layer, Distributed Systems, QA, SRE, and Support teams. Lead ambiguous, cross-functional engineering initiatives from design through delivery.

Build and maintain Camunda 8 backend data-layer services spanning relational databases and Elasticsearch/OpenSearch. Design scalable storage, query, retention, and streaming systems; improve performance, indexing, and production tooling. Lead engineering initiatives from solution design through delivery, collaborate across teams, provide L3 support, and participate in on-call rotations. Investigate production data issues and contribute to schema evolution, workflow automation, and CI improvements.

Lead architecture and backend development for international core systems, ensuring high availability, concurrency, security, and scalability. Design Java/Spring Boot services, optimize performance, integrate MySQL/Redis/Kafka, manage technical risk, drive productization, mentor engineers, and coordinate with suppliers and product teams. Onsite role in London supporting European operations.

Design, implement, and test cloud-based server-side software in Python. Optimize code performance, maintain unit and integration tests, and work with AWS, Docker, DevOps, and CI/CD tools. Preferred experience includes reverse engineering public APIs, PostgreSQL, Django ORM and DRF, network protocols, and web or mobile technologies.

Lead and deliver backend features for Repayment Scheduling: design and implement highly available distributed systems, collaborate with product/design/analytics, own operational reliability and on-call duties, mentor engineers, set quality standards, and drive technical decisions and delivery.

As a Staff Platform Engineer at Joko, you will lead platform efforts, ensure infrastructure reliability, enhance developer experience, and optimize costs, focusing on security and scalability while collaborating across teams.

Build and own end-to-end features across backend and frontend: design backend services and data models (Python/Django), implement RESTful APIs, create reusable frontend components (TypeScript/React), write tests, participate in code reviews, maintain production reliability and security, and collaborate with product and design.

Senior engineer owning feature lifecycle: design, architecture, implementation, reliability, and cross-team impact. Lead architecture, SRE/observability, security practices, mentor engineers, and drive product-technical alignment using AI-augmented workflows.

Develop and maintain multi-platform motion control and communication libraries and GUIs for servo drivers. Implement advanced identification and tuning algorithms, optimize performance, produce internal architecture and design documentation, define test plans with QA, and collaborate closely with firmware teams to deliver robust motion control products.

Design, build, and operate reliable, scalable backend services, APIs, and platform components. Lead complex feature development from planning through release, improve service performance, monitoring, alerting, observability, and operational readiness, and collaborate with engineering, product, and QA teams. Serve as a technical contributor for debugging and architecture decisions while mentoring junior engineers and advancing engineering standards.

Own and deliver backend identity systems for international markets, shaping technical direction, designing distributed, highly available services, and collaborating with product, design, and analytics. Improve reliability, performance, and operational health; participate in on-call rotation; set code and design standards; mentor and grow engineers; reduce toil and create runbooks/playbooks. Drive cross-team collaboration to meet regulatory and market-specific identity/KYC requirements.

Build and maintain hardened Ubuntu-based container images and the automated CI/CD pipelines to build, test, scan, sign, publish, and retire them. Integrate upstream open-source projects, ensure security and cloud-native compatibility, collaborate with cross-functional teams, document and share knowledge, mentor colleagues, and contribute to hiring. Work in a distributed agile environment with occasional travel.

Lead and deliver Repayment UX features for Affirm's mobile products using React Native. Own quarterly goals, guide engineers through ambiguous problems, collaborate with product/design/analytics, ensure operational reliability (metrics and on-call), improve engineering standards, and mentor teammates to drive high-quality, scalable mobile experiences.

As a Senior Engineer, you'll develop scalable, event-driven backend architectures, design low-latency APIs, and contribute to product development across the stack while optimizing performance and collaborating on AI features.

Own and build the Android client for an AI-first app: implement AI features (chat, vision, voice), optimize performance and memory, design UX for streaming and partial results, integrate backend APIs, instrument analytics/logging, and collaborate with backend and ML teams to ensure stability, security, and scalability in production.

As a Backend Software Engineer, you'll design scalable backend systems, optimize database performance, and collaborate with front-end and DevOps teams.

Contribute to Juju's development, collaborate with teams on distributed systems, debug issues, and enhance cloud automation features.

Design, implement, and maintain embedded real-time firmware for robotics platforms; own firmware lifecycle from architecture through validation and maintenance; diagnose system-level issues using hardware debugging tools; collaborate with electrical, controls, and software teams; advise leadership on firmware strategy and technical direction.