Senior Full Stack Engineer

• 4+ years of experience working with Python in a production environment

• 4+ 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 web applications

• Production MySQL experience and strong SQL skills; familiarity with NoSQL datastores

• Experience building, maintaining, testing and documenting APIs to be used by other developers both internally and externally

• 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

• Genuine interest in marketing and automation problems, and the aptitude to learn the domain quickly

• Experience building or integrating marketing technology (MarTech) stacks - e.g. CRM (HubSpot, Salesforce), CDP (Segment), email/marketing automation (Iterable), analytics (GA4, Amplitude) or ad platforms (Google Ads, Meta)

• Has built AI-powered tooling in production (LLM APIs such as OpenAI or Anthropic, agents or workflow automation) to streamline work for non-technical teams.

• Familiarity with the AWS ecosystem; knowledge of SQS (or similar such as RabbitMQ), SNS (or Kafka) and how they are used

• Experience with data stores like ElasticSearch, DynamoDB or similar

• Experience with cloud monitoring systems, such as Datadog

*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 a small, highly agile squad responsible for our Acquisition domain that owns, among other things, the marketing technology that brings customers to Bark. 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 our marketing stack and the AI-powered tooling we're building to automate and accelerate work across the business. You'll partner closely with our marketing function to design and ship internal tools that eliminate manual effort, accelerate campaigns, and enable teams to move faster, while building the customer-facing products that power our growth.

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 investing in the foundations of our new MarTech stack, and now we're ready to build on that even further to enable AB testing, a test-measure-learn approach and removing the bottlenecks of traditional SDLC through adding guardrails for improved efficiency. You'll be encouraged to contribute to new technology decisions, helping to shape our technology strategy and architecture as we grow.

• Work across the stack to build elegant, performant APIs, services and front-end experiences using Python and React/TypeScript

• Build and integrate with our marketing technology stack, connecting third-party platforms and internal services

• Work with Marketing to spot automation opportunities, then design and ship AI-powered internal tooling that removes manual work for marketing and other functions

• Measure the impact of the tools you build, using metrics such as adoption, efficiency gains, reduction in manual effort and overall business value.

• Build responsibly: bake in cost tracking, secret and PII hygiene, and a human review step before any AI-generated output goes live to customers.

• Collaborate with product managers, designers and marketing to move ideas quickly from prototype to production

• Proactively propose and implement improvements to our codebase and architecture

• Mentor and support other engineers, sharing knowledge and encouraging best practices across the team

• Proactively evaluate emerging AI tools and frameworks, make recommendations, and drive adoption across the business through documentation, reusable patterns and hands-on enablement.

• Help improve our ways of working internally and with stakeholders