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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Full Stack Engineer - Interaction Squad - **Company:** Bark - **Location:** Madrid, Spain (Remote available) - **Contract:** Permanent contract - **Skills:** A/B Testing, Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Apple IOS, Code Review, Data Migration, Data Stores, Cursor, Database Queries, Amazon DynamoDB, Elasticsearch, Google Analytics, Push Technology, Mobile Application Software, Python (Programming Language), MySQL, NoSQL, RabbitMQ, OpenAI, Twilio, TypeScript, Web Applications, Datadog, Cloud Monitoring, ReactJS, Large Language Models, Claude Code, Backend, Event Driven Architecture, Amplitude Analytics, Apache Kafka, Codebase, Front End Software Development, Amazon Simple Queue Service (SQS), Heap (Data Structure) - **Published:** November 3, 2026 - **Apply:** https://www.adzuna.es/details/5951077336 ## About the Role * 3+ years of experience working with Python in a production environment * 3+ years of recent experience working with React * Ideally, a 50/50 front-end and back-end split (though we're open to a 30/70 split either way if the fit is right) * Experience building scalable, high-performing, consumer-facing web applications * Production MySQL experience and strong SQL skills; familiarity with NoSQL datastores, and ideally experience migrating data between them * Experience designing, building, testing and documenting APIs used by other teams and clients, including mobile apps * A strong product mindset and genuine interest in user experience, conversion and the end-to-end customer journey * Strong organisational skills * Ability to achieve goals in a highly innovative and fast-paced environment * Great communication skills * Comfortable working with AI-assisted development tools (e.g. Claude Code, Cursor) as part of your day-to-day workflow, * Experience with communications platforms such as Twilio (voice, SMS) or GetStream (chat), or building real-time messaging and notification systems * Has built AI-powered features in production using LLM APIs such as OpenAI or Anthropic, including prompt and schema design, evaluation and PII handling * Experience building for, or alongside, native mobile apps (iOS/Android), including deep links and push notifications * Experience with event-driven architectures; familiarity with the AWS ecosystem, SQS (or similar such as RabbitMQ) and SNS (or Kafka) * Experience with data stores like ElasticSearch, DynamoDB or similar * Experience with experimentation and product analytics tooling (e.g. Heap, Amplitude, GA4) * Experience with cloud monitoring and incident tooling, such as Datadog and incident.io ## Description *Please note you must be based in Spain to be considered for this fully remote role. We are looking for a talented Senior Full Stack Engineer to join our growing team. You'll become a core part of the interactions squad, a small, highly agile squad that owns the consumer side of Bark's marketplace: the experience buyers have after posting a request, through being contacted by professionals, to hiring someone and leaving a review. You'll work equally on the frontend and backend, solving real user problems and scaling the systems behind them. A key focus of this role is the interaction layer between buyers and professionals. That includes our projects and contact services, in-app messaging and calling, notifications, and the AI-powered features we're building to make those interactions clearer, faster and more trustworthy, such as call summaries and conversation insights. You'll partner closely with product, design, data and our mobile engineers to ship features that measurably improve buyer conversion, engagement and satisfaction. You'll be someone who loves innovating and problem-solving, takes pride in knowing when to move fast and when to slow down, and can communicate trade-offs. We've spent the last year re-architecting the foundations of our consumer platform, extracting core services, consolidating our data model and unifying identity across buyer and professional accounts. Now we're ready to build on that to launch new products across our markets and run a test-measure-learn approach to the buyer journey. You'll be encouraged to contribute to technology decisions and help shape our architecture as we grow. Responsibilities * Work across the stack to build elegant, performant APIs, services and front-end experiences using Python and React/TypeScript * Design, build and evolve the core consumer services behind the buyer journey, such as projects, contacts and interactions, and integrate them cleanly with billing, messaging and the professional-side product * Build and integrate with third-party communication platforms (e.g. Twilio, GetStream) to power in-app messaging, calling and notifications * Design and ship AI-powered features for buyers and professionals, such as call and conversation summaries, from prototype to production * Measure the impact of what you build using metrics such as conversion, engagement, opt-in rates and customer satisfaction, and use the results to decide what to do next * Collaborate with product managers, designers, data analysts and mobile engineers to move ideas quickly from prototype to production, including A/B tests and market-by-market rollouts * Own the reliability of what you ship: write well-tested code, add useful observability, and take part in investigating and resolving incidents * Proactively propose and implement improvements to our codebase, data model and architecture * Mentor and support other engineers, sharing knowledge and encouraging best practices across the team * Proactively evaluate emerging AI tools and frameworks, including AI-assisted development and code review, and help the team adopt them with sensible guardrails * Help improve our ways of working internally and with stakeholders