Top Software Engineer Jobs in Barcelona

Owns technical direction and execution for major products and systems. Designs scalable, reliable architectures across backend, frontend, APIs, databases, and infrastructure; writes code; leads architecture decisions; resolves complex production issues; improves engineering quality; drives critical initiatives; and mentors engineers across teams.

Design, develop and operate scalable Python backend services, REST APIs and cloud-native infrastructure for connected health devices. Improve performance, observability, deployment pipelines and system reliability; collaborate across Product, AI, Embedded and Frontend teams; mentor engineers and drive architectural decisions through production deployment.

Lead and evolve QA strategy and automation frameworks across backend, frontend and embedded systems. Design and maintain automated tests, integrate into CI/CD, define release acceptance criteria and quality gates, perform functional/regression/integration testing, analyze production issues, monitor quality metrics, and promote a quality-first culture.

Senior full-stack product engineer owning features end-to-end: research customer problems, write product specs and wireframes, design and implement frontend and backend solutions, collaborate with product, design and infra, and ship high-quality, scalable features for tens of thousands of users.

Senior full‑stack product engineer owning large product areas end-to-end: research, specs, wireframes, implementation, and shipping reliable features. Collaborate with product, design, and infra; balance speed and quality; solve ambiguous customer problems and build scalable abstractions.

Build and enhance GraphAware Hume, a graph-powered analytics platform. Responsibilities include developing APIs, designing secure and scalable access-control systems, orchestrating workflows for graph analytics and real-time insights, optimizing application performance, contributing to architecture and technical design, and collaborating with distributed engineering teams.

Senior-level software engineer responsible for designing, developing, and maintaining scalable Java-based microservices and APIs. Collaborates with product and analytics, mentors junior engineers, participates in SDLC and code reviews, and ensures API security and quality. Works across cloud (AWS), containers, frontend/mobile (React/React Native, iOS/Android), and DevOps practices.

The Backend Engineer will develop and maintain features for Restream web services, design backend APIs, ensure infrastructure resilience, and contribute to a collaborative team environment.

Develop and optimize Soroban smart contracts and integrate anchor services on the Stellar network for cross-border payment solutions. Collaborate with cross-functional teams, test and debug smart contracts, document development processes, provide technical support, and stay current with blockchain and payments technology trends to ensure secure and efficient implementations.

Implement and optimize EVM-compatible features, reduce gas usage, develop and test smart contracts, collaborate on Ethereum infrastructure, and provide technical support.

Build and maintain high-security mobile wallet apps using React Native, Swift, or Kotlin. Implement biometric authentication and secure key storage, collaborate with cross-functional teams, debug performance issues, and propose UX and security improvements.

Lead the architecture, development, and delivery of scalable backend systems, APIs, data pipelines, and services supporting global 3D and computer vision applications. Drive technical direction, system performance, resiliency, observability, and maintainability. Mentor senior engineers, conduct architecture reviews, lead cross-functional initiatives, influence hiring and team growth, and shape engineering culture and long-term technical vision.

The Senior Software Engineer will design and develop high-quality web and mobile applications, ensuring code quality while collaborating with product teams and mentoring junior engineers.

Build and maintain user-facing features and interfaces for Restream web services. Design and implement UI and business logic, collaborate with product designers and engineers, perform code reviews, improve reliability and scalability, and evaluate emerging technologies.

Join the Kubernetes product team to design and implement Kubernetes operators and addons, write high-quality Golang and Python code, debug issues, collaborate with a distributed team, mentor colleagues, and contribute to open-source integration and lifecycle management. Travel 2–4 weeks yearly for team events.

Design, develop, and maintain backend and mobile software systems. Lead and mentor engineers, follow SDLC and agile/DevOps practices, build secure REST/JSON APIs, perform advanced debugging, refactor code, and collaborate with product and analytics.

Build and maintain services and tooling to automate and secure network lifecycle across data centers. Implement CI/CD, staged rollouts, drift detection, observability pipelines, and APIs that integrate network source-of-truth with the cloud platform. Collaborate with network engineers and SREs to turn operational pain into production-grade automation and tooling.

Design and build scalable, secure .NET-based web applications and REST APIs. Partner with multidisciplinary teams and clients to translate requirements into high-quality solutions, using Azure services and ORM technologies like Entity Framework. Advocate for modern practices, contribute to architecture, and support continuous learning and product development.

Work on Percona's open-source MongoDB operational tools (primarily ClusterSync and also Backup). Build and harden a Go-based replication engine handling initial cloning and continuous change streams, ensure correctness and fault tolerance at scale, support sharded clusters, optimize performance and resource usage, and maintain CLI/HTTP APIs, metrics, logging, tests, and packaging. Collaborate openly via GitHub pull requests and JIRA.

Develop core backend components for a blockchain network, focusing on networking, reliability, scalability, and high-quality software practices.

Develop and enhance front-end, server-side, and database applications, focusing on blockchain products while ensuring high performance and security.

As a Distributed Systems Engineer, you'll design and evolve LiveKit's core systems, implement resilient architectures, and enhance reliability and developer velocity, working on critical features in production environments.

Design and evolve core control, data, and observability systems; implement resilient region-spanning architectures; build libraries, protocols, and tooling; diagnose and harden critical paths using metrics, tracing, and testing; and shape platform capabilities across identity, scheduling, observability, and distributed state management.

The role involves designing and evolving core systems at LiveKit, implementing resilient architectures, and building tools to enhance system reliability and developer speed. Strong distributed systems experience and programming skills are essential.

Design, implement, and operate low-latency, highly available distributed control, data, and observability systems. Build region-spanning architectures, libraries, protocols, and tooling; diagnose and harden critical paths using metrics, tracing, testing, and real traffic; and shape platform capabilities around identity, scheduling, observability, and distributed state management.