Top Tech Jobs & Startup Jobs in Madrid

Invitation for unsolicited applications: candidates can send a spontaneous application describing their skills and desired role. The company will review submissions and consider potential matches.

Design, develop, and maintain reusable component-based frontend architecture; optimize performance and UX; write unit and integration tests; mentor mid and junior developers; collaborate via pair programming and knowledge sharing; drive continuous improvement of development processes and codebase.

Build and maintain Semrush's internal cloud platform: automate infrastructure and tooling (Python/Go), manage public cloud (primarily GCP), Kubernetes/Docker, IaC and CI/CD, support engineering teams, improve reliability/observability, contribute to security/compliance, and participate in on-call rotation.

Design, build, and optimize LLM- and NLP-based systems for AI search products. Create evaluation frameworks and benchmarks, perform brand/entity/domain extraction, improve model pipelines for quality, cost, and throughput, write production-quality Python, and collaborate with Product, Engineering, and Data Science to deploy working solutions.

Join a cross-functional Agile team to develop backend components using C#/.NET in cloud-based, microservices architectures. Participate in design, code reviews, testing (unit, integration, functional), documentation, debugging, and ongoing maintenance.

Manage end-to-end sourcing and contracting for delegated spend across indirect categories. Run sourcing events, negotiate contracts, ensure supplier performance, resolve disputes, support change management, and deliver cost savings and compliance while collaborating with Procurement, Legal, Finance, and business stakeholders.

Maintain and audit rebate and promotion programs, ensure accurate booking of customer invoices, ensure compliance with internal policies and regulations, collaborate with sales, finance and management to mitigate financial risks and support financial reporting and budgeting.

Provide HR and payroll support to employees across EMEA via phone, email, web-form and chat. Troubleshoot and resolve inquiries, escalate complex issues, promote self-service, maintain case records, contribute to process improvements and knowledge base content while meeting service levels.

Partner with leaders across Creative, Growth, Tech and Ops to design and run performance management, compensation, onboarding, engagement, HR ops, compliance, L&D and people analytics. Coach managers, implement competency frameworks, run pulses and OKR-linked KPIs, automate HRIS workflows, and measure impact via eNPS, retention, SLAs and time-to-proficiency.

Remote research internship supporting semiconductor and AI industry analysis: data collection, market research, basic financial modeling, preparing reports and presentations, attending team meetings, and developing research skills with mentorship and feedback.

Design, develop, and deploy high-volume, low-latency Java applications and microservices. Lead full development lifecycle, write testable code, manage releases, improve architecture, and support Agile/Scrum processes.

Provide expert rater support by coaching and mentoring raters, creating unbiased annotation and gold sets, running client test rounds, analyzing datasets and KPIs, crafting client communications, and collaborating with R&D to improve AI advertising data quality.

Lead and mentor rater teams to ensure consistent, unbiased annotations and gold set creation. Facilitate client test rounds, analyze datasets and KPIs, craft client communications, collaborate with R&D, and independently evaluate and improve rating quality for AI-powered advertising systems.

Design end-to-end product experiences for BJAK's financial products. Create user flows, wireframes, prototypes and polished interfaces; build scalable design systems; collaborate with product and engineering; iterate using data and user feedback to improve usability and consistency across mobile and web.

Design and deliver high-quality iOS and Android mobile interfaces for fintech products: create wireframes, prototypes, production-ready UI, maintain mobile design systems, ensure platform guideline compliance, accessibility, and collaborate with engineers and PMs to iterate based on analytics and user feedback.

Design polished, user-centric mobile and web interfaces for BJAK's AI-driven financial products. Create wireframes, flows, prototypes and high-fidelity UI, evolve the design system, collaborate with product and engineering, iterate from user feedback and analytics, and ensure accessibility, responsiveness and visual consistency across devices.

Lead the Human Data function to deliver high-quality training data and evaluations. Manage Team Leads and AI Tutors, define annotation guidelines and QA processes, scale operations globally, recruit and develop talent, collaborate with engineering and program teams, and report outcomes to senior leadership.