Top Software Engineer Jobs in Barcelona

Build, maintain, scale, and support globally distributed streaming services handling high-throughput platform data. Develop automation and tooling for reliability, scalability, and operational stability; participate in architecture, Agile team processes, shared code ownership, and on-call rotations. Work with streaming platforms, distributed systems, concurrency, production scaling, Kubernetes, and observability solutions.

Design, build, and maintain scalable backend services, APIs, and integrations used across multiple King games. Own features from design through production support, improve system reliability, observability, and automation, collaborate with cross-functional teams, contribute to architecture and code quality, and explore integrating AI capabilities into player support tools.

Build AI agents, reusable agent platforms, and automated workflows across the software development lifecycle. Develop integrations with codebases, APIs, MCPs, internal tools, and engineering systems. Prototype and scale AI capabilities, while designing context management, orchestration, verification, and human-in-the-loop mechanisms for safe, reliable automation. Measure agent effectiveness and collaborate with engineering, product, design, and data teams to identify automation opportunities and drive adoption.

Own end-to-end B2B merchant product initiatives, from understanding problems and defining hypotheses through building, shipping, measuring, and iterating. Work across backend and frontend production software, collaborate directly with merchants and stakeholders, make product and technical decisions amid ambiguity, and use data, experimentation, and AI-assisted development to deliver outcomes.

As a Software Engineer on the Platform team, you'll design, develop, and maintain backend APIs, enhance system performance, and collaborate across teams to align architecture with product strategy.

Build and maintain Ergodic AI’s AI platform across back-end and front-end systems. The role involves developing with Python web frameworks and JavaScript/TypeScript, integrating with client technology stacks and workflows, applying AI, ML, and LLM concepts, and contributing to DevOps, cloud deployment, testing, and infrastructure practices. As an early-stage hire, the engineer will help shape the product and solve complex data and AI challenges.

Design, build, and operate a large-scale Kubernetes platform: ensure high availability and performance, automate platform delivery, develop custom Kubernetes Operators in Go, manage production incidents, and run Day 1/Day 2 cluster operations with Helm and GitOps tooling.

Build and ship reliable, scalable, production-quality software across the stack for an equity management and financial reporting platform. Responsibilities include developing user-facing features, working with product managers and designers, contributing to data models and workflows, participating in code reviews and architecture discussions, and owning medium-sized projects through release. Teams focus on equity logic, automation, reporting, or tax workflows.

Build and operate backend services supporting millions of emails. Own features end to end, design reliable distributed systems, scale APIs and databases, manage cloud infrastructure, improve observability and deployments, and participate in on-call rotation. Collaborate with customers and support to improve the product, strengthen engineering quality, and deliver complete experiences across the stack.

Leads the design, development, maintenance, testing, troubleshooting, and optimization of complex full-stack software applications. Collaborates with cross-functional teams, documents technical requirements, resolves IT issues, prepares data, supports end users, and applies software architecture, microservices, database, CI/CD, containerization, monitoring, and Agile engineering practices.

Design and develop scalable backend systems for a B2B application using Java and Spring. Participate in architectural decisions involving performance, security, and scalability; apply agile practices; mentor developers; optimize relational database performance; and support cloud and DevOps initiatives, particularly on AWS.

Design, build, and scale backend services for a high-volume distributed tracing pipeline. Work on distributed system challenges, create automation and tooling, participate in architecture, collaborate with product teams, use DevOps practices and on-call rotations, and apply AI tools to accelerate development.

Design and develop clean, maintainable software for automated document-processing products. Collaborate with business stakeholders to translate requirements into product improvements, conduct code reviews, guide technical direction, mentor colleagues, and improve engineering practices. The role uses Golang, MySQL, Docker, Kubernetes, cloud infrastructure, and GitHub CI/CD while emphasizing product ownership, clean architecture, software craftsmanship, and technical communication.

Build, maintain, and scale backend services for a high-volume distributed ingest and processing pipeline. Integrate AI agents into engineering workflows, create automation and tooling, collaborate with product teams, participate in on-call rotations, and champion observability and continuous workflow innovation.

Lead the modernization of business-critical legacy PHP systems into scalable Node.js and Next.js architectures. Provide hands-on coding, architectural guidance, API and microservices design, debugging, refactoring, and incremental migration leadership. Translate undocumented business logic into maintainable solutions, leverage AI-assisted development tools, communicate trade-offs to stakeholders, establish engineering standards, and mentor additional engineers.

Design, build, and maintain backend collections systems to manage delinquent loans. Collaborate with product, risk, and engineering teams, deliver features in phases, support operations and on-call rotation, instrument monitoring, and participate in hiring and team growth.

Build and ship backend features for enterprise Coder deployments, including database migrations, observability, reporting, auditing, security, scalability, and reliability improvements. Investigate production issues, resolve operator problems, document designs, participate in code reviews and RFC discussions, and join on-call rotations. The role requires professional Go development, concurrency knowledge, SQL expertise, debugging ability, and strong communication.

Build and maintain full-stack internal tools, automated workflows, and customer-facing features using TypeScript, Node.js, and React. Integrate LLMs, AI services, third-party APIs, and external platforms. Use AI coding assistants to prototype, develop, test, and improve reliable software. Collaborate with internal users, product managers, designers, engineers, and the Chief AI Officer in an Agile environment while contributing to architecture, code reviews, UX, security, performance, and continuous improvement.

Build and maintain backend collections systems to manage delinquent loans, implement recovery strategies, ensure high availability and reliability, collaborate with product and risk teams, participate in on-call rotation, write well-tested extensible code, and contribute to team growth.

Own and scale a live production backend supporting real-time communication between apps, animation models, and LLM providers. Design APIs, WebSockets, data storage for companion memory and conversation state, and Cloudflare Workers infrastructure. Improve latency, throughput, cost, observability, alerting, incident response, and documentation while collaborating with the team to ship features end to end.

Build and evolve Rerun’s open-source viewer, cross-language SDKs, and integrations with Rerun Hub. Develop high-performance interfaces for large-scale multimodal data, optimize workflows across desktop and web, make full-stack architecture decisions, and collaborate with backend, Hub, design, customers, and the open-source community. The role involves UI development, rendering, data handling, infrastructure, real-time applications, visualization, and performance optimization.

Develop and optimize software solutions for industrial additive manufacturing in an agile team. Responsibilities include designing algorithms, data structures, and software subsystems; debugging complex issues; benchmarking and improving performance, stability, efficiency, and scalability; and contributing to software quality and documentation. The role uses Vue.js, TypeScript, Python, C++, MongoDB, Docker, and automated development tools.

As a Software Engineer, you'll design and develop software solutions, solve technical problems, lead projects, and collaborate with product and operations teams.

Design, implement, test, and optimize features for Candy Crush Soda Saga. The Software Engineer will contribute to game engines, systems, platforms, and the global codebase while taking technical ownership of deliverables, monitoring technical metrics, and collaborating on feature development. Strong C++ skills, code quality, performance awareness, and passion for mobile gaming are required; Android or iOS experience is advantageous.

Build and deploy software for Stripe’s financial infrastructure, specializing in frontend or related technical areas. Collaborate on multi-person coding projects, learn unfamiliar systems, contribute to large codebases, participate in code reviews, and safely update production systems. New graduates are expected to apply strong programming fundamentals, communicate clearly, use AI tools responsibly, and solve complex technical problems with increasing independence.