Senior Full-stack Developer, Python/FastAPI, React & SQL w Poland, Warszawa

We are launching a new multi-cloud product and need a Senior Full-stack Developer to own full-stack delivery from Python/FastAPI APIs to React/TypeScript UI. You will optimize PostgreSQL and OpenSearch performance and collaborate in a Databricks-heavy environment. Apply today. Responsibilities Develop and enhance web applications using Python/FastAPI and SQLDefine and implement APIs and integrations that support high-load database operationsOptimize and troubleshoot query performance in production systemsDeliver front-end work using TypeScript and ReactIncorporate GenAI engineering tools to improve development workflowsWork collaboratively while independently owning assigned tasksMaintain proactive communication with stakeholders and teammatesOwn features end to end and contribute beyond ticket completionExecute effectively through ambiguity in a fast-paced startup environment Requirements Demonstrated 5+ years of production delivery with Python, FastAPI, and SQLAdvanced knowledge of web application development, API design, and integration workHands-on ability to operate high-load databases and optimize query performanceFamiliarity with TypeScript and React and willingness to work across the full stackPractical experience with GenAI engineering tools, ideally Claude CodeStrong communication abilities and proactive ownership, comfortable working solo and with a teamTrack record of navigating ambiguity and shipping without constant direction in a transparent, fast-moving startup environmentEnglish proficiency at B2 (Upper-Intermediate) level or higher Nice to have Experience with TypeScript, React, https://jobeax.com/link/Z30sZYC3jcRenVso, Storybook, Playwright, Radix UI, and ZustandExperience working with PostgreSQL and OpenSearchKnowledge of cloud platforms, Infrastructure as Code, and related toolsData engineering experience using PySpark and SparkSQLClient-facing experience 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.