Senior Full-stack Developer w Warszawa, Polska

We're seeking a Senior Full-stack Developer to help build a new product using Python and FastAPI for the backend, React/TypeScript for the frontend, and PostgreSQL and OpenSearch for database management. The product runs in a multi-cloud environment and relies heavily on Databricks. Responsibilities Build and maintain web applications with Python/FastAPI and SQLDesign APIs and integrations that handle high-load database operationsImprove query performance across production systemsSupport front-end development efforts using TypeScript and ReactUse GenAI engineering tools to enhance development workflowsWork both collaboratively with the team and independently on assigned tasksMaintain proactive communication with team members and stakeholdersOwn product features and contribute meaningfully beyond simply completing ticketsHandle ambiguity and deliver results within a fast-paced startup setting Requirements 5+ years of hands-on production experience with Python, FastAPI, and SQLStrong expertise in web application development, API design, and integrationsSkilled in managing high-load databases and optimizing query performanceSome front-end experience with TypeScript and React, along with openness to full-stack workPractical experience using GenAI engineering tools, Claude Code preferredExcellent communication skills and a proactive mindset, comfortable working solo or as part of a teamAbility to navigate ambiguity and make progress independently in a transparent, fast-moving startup settingEnglish fluency at B2 level or above Nice to have Strong background in TypeScript, React, https://jobeax.com/link/Z30sZYC3jcRenVso, Storybook, Playwright, Radix UI, and ZustandHands-on experience with PostgreSQL and OpenSearchKnowledge of cloud platforms, Infrastructure as Code, and related toolingExperience in data engineering, particularly working with PySpark and Spark SQLPrior experience working directly with clients We offer We gather like-minded people:Top tech minds driving innovation in AI, cloud and digital platform modernizationSupportive team and agile, startup-like cultureHybrid by design mode and opportunity to work remotely within PolandChance to work abroad for up to 60 days annuallyBusiness-driven relocation opportunitiesWe provide growth opportunities:Career development programsThought leadership, mentoring, soft skills and well-being programsCertification (Anthropic, Gemini, GCP, Azure, AWS)English classesWe cover it all:Stable payParticipation in the Employee Stock Purchase Plan with a 15% discountBenefits package (health insurance, multisport, shopping vouchers)Referral bonuses up to $2,000Offices featuring entertainment and relaxation zones, table tennis and football, free snacks, coffee and moreCorporate, social and well-being eventsPlease, note:Benefits listed above are available to employees onlyWe are open for working with Contractors. Terms of B2B cooperation agreements are agreed individuallyWe will reach out to selected candidates exclusively EPAM is global leader in AI transformation engineering and integrated consulting, serving Forbes Global 2000 companies and ambitious startups. With over thirty years of expertise in custom software, product and platform engineering, we empower our clients to become AI-Native enterprises, driving measurable value from innovation and digital investments.