Lead Developer / Senior Software Engineer (Python, AWS, React)

🏢 Summary: Remote Senior Software Engineer role starting in September, building a cloud-native Clinical Data Layer that standardizes clinical trial data to the CDISC SDTM model. The role owns end-to-end backend, data-pipeline, API, frontend, and infrastructure features using Python and AWS. 🗂️ Requirements: 5+ years of professional software engineering experience, Python proficiency, AWS expertise: Lambda, Step Functions, S3, DynamoDB, IAM, Ability to evaluate cost, latency, and failure modes 📃 Skills: Python, AWS, Lambda, StepFunctions, S3, DynamoDB, IAM, GraphQL, AppSync, React, TypeScript, Terraform, Databricks, CDISC, SDTM, ADaM, GxP 🏢 Description: Project start: September 100% remote Description Join the team building the Clinical Data Layer, a cloud-native platform that standardizes clinical trial data to the CDISC SDTM model at scale. Work across a Python/AWS backend and a React frontend, owning features end-to-end from data pipeline design through the analyst-facing specification authoring tool. What You'll Do - Design and extend the SDTM transformation engine, including AWS Step Functions orchestration, Lambda workers, and Databricks write paths. - Build and evolve the GraphQL/AppSync API and React frontend used by analysts to author mapping specifications. - Own infrastructure-as-code changes across service Terraform stacks and shared infrastructure. - Participate in code review, architecture discussions, and on-call rotation. - Mentor engineers newer to the stack or clinical data domain. What We're Looking For Must-Have - 5+ years of professional software engineering experience. - Python proficiency, including Lambda Powertools, pytest/pytest-bdd, and clean, testable Python development in a monorepo context. - AWS depth with Lambda, Step Functions, S3, DynamoDB, and IAM; ability to reason about cost, latency, and failure modes. Strong Plus - GraphQL/AppSync experience, including schema design, resolvers, and consuming AppSync from a React client. - React and TypeScript experience, with the ability to contribute to a Vite/Cloudscape SPA without being a frontend specialist. - Infrastructure as code with Terraform, including reading, writing, and debugging multi-stack configurations. - Databricks or similar large-scale data processing platform experience. - Clinical data standards knowledge, including CDISC SDTM and ADaM, or regulated-industry software development experience, including GxP and 21 CFR Part 11. - Understanding of event-driven and distributed-system patterns, including fan-out/fan-in, idempotency, and at-least-once delivery.

🏢 Summary: Long-term B2B contract for a Senior Frontend Developer focused on building and evolving frontend applications using React and TypeScript within a serverless AWS environment. The role involves designing, developing, and integrating frontend solutions with cloud services in an Agile team. Strong practical experience with AWS and serverless architecture is essential. 🗂️ Requirements: Senior-level experience in frontend development, Strong knowledge of React, Strong knowledge of TypeScript, Commercial experience with AWS, Experience with serverless architecture, Experience with AWS Lambda, Experience with AWS CDK or similar infrastructure tools 📃 Skills: React, TypeScript, AWS, Lambda, CDK, Serverless 🏢 Description: Senior Frontend Developer / Senior React Developer Zaangażowanie: długoterminowe Wymiar pracy: full-time Forma współpracy: B2B Start: ASAP Język pracy: angielski Środowisko pracy: Agile Dołączysz do długoterminowego projektu jako Senior Frontend Developer, pracując przede wszystkim z Reactem i TypeScriptem. Projekt jest realizowany w środowisku opartym o AWS oraz podejście serverless, dlatego ważne jest realne doświadczenie z usługami chmurowymi, a nie tylko podstawowa znajomość AWS. Na co dzień będziesz współpracować z zespołem technicznym w środowisku Agile, brać udział w projektowaniu i rozwijaniu rozwiązań frontendowych oraz współpracować z zespołem backendowym/fullstackowym przy integracji aplikacji z usługami chmurowymi. Nasze wymagania: doświadczenie na poziomie Senior Frontend Developer, bardzo dobra znajomość React jako głównej technologii, bardzo dobra znajomość TypeScript, realne doświadczenie komercyjne z AWS, znajomość podejścia serverless, w tym pracy z AWS Lambda, doświadczenie w pracy z AWS CDK lub podobnymi narzędziami infrastrukturalnymi, bardzo dobra komunikacja w języku angielskim, proaktywność, samodzielność i umiejętność jasnego omawiania tematów technicznych, gotowość do udziału w szczegółowym interview technicznym i komunikacyjnym. Mile widziane: znajomość Node.js, doświadczenie fullstackowe, przy zachowaniu frontendowego profilu roli, znajomość Terraform, doświadczenie z GitHub Actions, znajomość Datadog, doświadczenie z GitHub Copilot, doświadczenie w projektach opartych o architekturę serverless. Technologie: React, TypeScript, AWS, AWS CDK, AWS Lambda, Node.js, Terraform, GitHub Actions, Datadog, GitHub Copilot. Zakres zadań: rozwój aplikacji frontendowych w React i TypeScript, projektowanie i wdrażanie rozwiązań zgodnie z dobrymi praktykami frontendowymi, współpraca z zespołem pracującym w architekturze serverless na AWS, udział w technicznych dyskusjach, code review i podejmowaniu decyzji projektowych, integracja aplikacji z usługami backendowymi i chmurowymi, praca z narzędziami CI/CD oraz monitoringiem, aktywna komunikacja z zespołem i interesariuszami w języku angielskim.

🏢 Summary: Senior Lead Engineer role focused on leading architecture and delivery of high-scale enterprise systems using React, Node.js, and TypeScript, while integrating advanced AI agents into deterministic workflows. The position combines hands-on development, technical leadership, and ownership of mission-critical systems in close collaboration with AI architects. It offers high impact on production-ready AI solutions for global enterprises. 🗂️ Requirements: 10+ years of software engineering experience, Proven experience in Lead, Principal, or Expert engineering roles, Expert-level knowledge of React, Expert-level knowledge of Node.js, Expert-level knowledge of TypeScript, Experience designing and scaling enterprise systems, Experience conducting code reviews and mentoring engineers, Ability to integrate AI/LLM agents into enterprise systems, Strong problem-solving skills for complex production issues, English proficiency at minimum B2 level 📃 Skills: React, Node.js, TypeScript, JavaScript, LLM, AI, Neurosymbolic, State, Machines, Python, NX, Snowflake 🏢 Description: Position: Senior Lead Engineer (React, Node.js & AI) Location: Kraków (full time office) Salary: 35,000 – 45,000 PLN net + VAT (B2B) + 10% yearly performance bonus About the Project Our Client is an innovative software company specializing in transforming raw AI capabilities into durable, deterministic enterprise systems. Known for their elite engineering culture, they specialize in delivering high-scale, production-ready AI solutions for global Fortune 500 enterprises. As a Senior Lead Engineer, you will become the right hand to the Principal Architect. This is a high-impact, operational leadership role where you will take full accountability for core React/Node/TS interfaces and backend systems, mentor the engineering team, and seamlessly integrate cutting-edge AI agents into complex enterprise workflows. Your leadership will drive delivery, allowing the Principal Architect to focus entirely on macro-level AI strategies and frontier models. Your Role Architecture & Delivery: Designing, building, and scaling core enterprise systems and interfaces using React, Node.js, and TypeScript. Technical Leadership: Taking extreme ownership of the codebase, enforcing world-class standards, conducting code reviews, and mentoring the engineering team to help them grow into independent problem solvers. AI Integration: Collaborating closely with the AI architecture team to embed LLM agents, neurosymbolic systems, and state machines into secure, deterministic enterprise workflows. Problem Solving: Acting as the ultimate escalation point for complex technical challenges, leading the charge to unblock production when critical issues arise. Strategic Execution: Translating high-level business requirements and macro-architecture directly into flawless, high-performing code that creates durable operating leverage. Requirements Experience: 10+ years of hard-core software engineering experience, with a proven track record in Lead, Principal, or Expert roles. Tech Stack Mastery: Absolute, atomic-level expertise in React, Node.js, and TypeScript ecosystem. Extreme Ownership: A proactive mindset – you don’t wait for tasks; you identify problems, design solutions, align resources, and deliver with absolute certainty. Leadership & Mentoring: Ability to elevate the team, set uncompromising quality standards, and guide junior/mid engineers. Business DNA: Deep understanding that code serves tangible business goals (ROI) and creates long-term value, rather than just being technical art. Communication: English at minimum B2 level to collaborate effectively with an elite team and global partners. Nice to have Practical experience or strong interest in Python, NX, and Snowflake. Hands-on exposure to frontier AI/LLM models and agents. What We Offer Global Impact: The chance to build next-generation neurosymbolic systems redefining how global enterprises utilize AI. Elite Environment: Direct collaboration alongside C-level executives, visionaries, and core software architects. High-End Hardware: New Apple MacBook Pro and external monitors provided as needed. Flexible Culture: Flexible working hours within a modern, fully-equipped office setup. Premium Office Perks: Access to a modern office in Kraków featuring a playroom, bike parking, shower, free coffee, beverages, and snacks (with no dress code). Growth & Benefits: Dedicated conference budget to support your continuous professional development.

🏢 Summary: Senior React Developer with AWS role focused on designing and architecting scalable, cloud-native web applications for digital banking platforms using React, TypeScript, and AWS in an on-site model in Warsaw. The position involves leading technical decisions, building serverless solutions, and supporting cloud migration initiatives. The role combines hands-on development with architectural guidance in a modern, microservices-driven environment. 🗂️ Requirements: 8+ years of software engineering experience, Strong expertise in React, Strong expertise in TypeScript, Hands-on experience with AWS (Lambda, Batch, CloudWatch), Proficiency in Terraform or other Infrastructure-as-Code tools, Experience with relational and non-relational databases (MongoDB, ElasticSearch, S3), Knowledge of RESTful API design and development, Bachelor’s degree in Computer Science, Engineering, Mathematics or related field, Fluent Polish and English, Legal right to work in Europe 📃 Skills: React, TypeScript, AWS, Lambda, Batch, CloudWatch, Terraform, MongoDB, ElasticSearch, S3, REST, CI/CD, Serverless, Microservices 🏢 Description: Empower the Future of Financial Technology — Design Scalable, Cloud-Native Applications with React and AWS Warszawa-based opportunity with on-site work model As a Senior React Developer with AWS , you will be working for our client, a global leader in financial technology dedicated to transforming the industry with innovative, cloud-native web solutions. Join this high-impact project to shape the future of digital banking platforms, leveraging AI, microservices, and modern development practices. Be a vital part of a forward-thinking environment driving cutting-edge cloud migration strategies, delivering scalable and high-performance systems across international markets. Your main responsibilities: Architect and engineer modern web applications using React, TypeScript, and AWS services Lead technical decision-making and provide architectural guidance to the development team Develop and maintain serverless solutions utilizing AWS Lambda, Batch, and CloudWatch Write Infrastructure-as-Code with Terraform to streamline deployment and infrastructure management Collaborate with designers, product managers, and stakeholders to translate requirements into robust solutions Support migration of legacy systems toward cloud-native, React-based architectures Optimize CI/CD pipelines for automated, efficient deployment Work with cloud storage solutions such as S3, MongoDB, and ElasticSearch You're ideal for this role if you have: 8+ years of practical software engineering experience Strong expertise in React and TypeScript Hands-on experience with AWS services, especially Lambda, Batch, and CloudWatch Proficiency with Terraform or similar Infrastructure-as-Code tools Solid understanding of relational and non-relational databases (MongoDB, ElasticSearch, S3) Knowledge of RESTful API design and development Excellent communication skills to engage with non-technical stakeholders Bachelor's degree in Computer Science, Engineering, Mathematics, or related field It is a strong plus if you have: Experience with CI/CD pipelines Familiarity with serverless architecture best practices Knowledge of AI development tooling in cloud environments Language Required for the role: Fluent in Polish and English Eligibility to work in: Only candidates with an existing legal right to work in Europe will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Fullstack Software Engineer & Tech Lead role focused on designing and delivering scalable, cloud-native applications on AWS using modern full-stack technologies. The position combines hands-on development with technical leadership, architecture design, and infrastructure automation. The engineer will drive end-to-end solutions, from UI and APIs to CI/CD and Infrastructure-as-Code. 🗂️ Requirements: 8+ years of software engineering experience, Strong experience in full-stack development, Expertise in TypeScript, Experience with React, Hands-on experience with AWS, Experience with serverless services (Lambda, Batch), Knowledge of Infrastructure-as-Code (Terraform or CloudFormation), Experience with RESTful API development, Experience with relational databases, Experience with NoSQL databases, Experience with CI/CD pipelines, Ability to lead technical design and mentor engineers 📃 Skills: TypeScript, React, AWS, Lambda, Batch, Terraform, CloudFormation, REST, SQL, SQLServer, DB2, Sybase, MongoDB, Elasticsearch, CI/CD 🏢 Description: Senior React Developer with AWS Join a global leader in financial technology as a Senior React Developer with AWS, shaping the future of innovative, cloud-native web applications. In this high-impact role, you'll spearhead the design and development of cutting-edge solutions at a major international institution, collaborating with cross-functional teams across Warsaw, London, New York, and India. Be part of a forward-thinking environment driving a transformative cloud migration strategy, leveraging AI and modern development practices to deliver scalable, high-performance platforms. What You'll Do: Architect and engineer modern web applications using React, TypeScript, and AWS Lead technical decision-making and provide architectural guidance to the development team Develop and maintain serverless solutions with AWS Lambda, Batch, and CloudWatch Write Infrastructure-as-Code with Terraform to streamline deployment and infrastructure management Collaborate closely with designers, product managers, and stakeholders to translate requirements into robust solutions Support migration of legacy systems to cloud-native, React-based architectures Optimize CI/CD pipelines for automated, efficient deployment Work with cloud storage solutions such as S3, MongoDB, and ElasticSearch Required Skills: 8+ years of practical software engineering experience Strong expertise in React and TypeScript Hands-on experience with AWS services, especially Lambda, Batch, and CloudWatch Experience with Terraform or similar Infrastructure-as-Code tools Solid understanding of relational and non-relational databases (MongoDB, ElasticSearch, S3) Knowledge of RESTful API design and development Excellent communication skills, capable of engaging with non-technical stakeholders Bachelor’s degree in Computer Science, Engineering, Mathematics, or related field Nice to Have Skills: Experience with CI/CD pipelines Familiarity with serverless architecture best practices Knowledge of AI development tooling in cloud environments Preferred Education and Experience: Bachelor’s or higher degree in a technical discipline 8+ years of professional experience in software engineering, with a focus on full-stack and cloud-native solutions Other Requirements: Ability to work in an on-site environment in the centre of Warsaw Willingness to contribute to a dynamic, global team driven by innovation and excellence Bring your expertise to a role that truly makes an impact - apply now and help shape the future of financial technology!

🏢 Summary: Senior Frontend Engineer role focused on building and scaling AI-powered Next.js applications with complex state management, real-time interactions, and enterprise-grade frontend architecture. The position involves owning frontend delivery, designing intuitive AI user experiences, and optimizing performance, accessibility, and scalability for high-load products. Hybrid full-time B2B engagement with a competitive salary range. 🗂️ Requirements: 5+ years of frontend engineering experience, 3+ years of React and TypeScript experience, Production experience with Next.js SSR applications, Knowledge of SSR, SSG, CSR trade-offs, Experience with complex state management, Experience building AI/LLM interfaces, Experience optimizing Core Web Vitals and frontend performance, Knowledge of localization, accessibility, security, and compliance, Security-conscious engineering approach, Experience using AI coding agents, Strong communication skills 📃 Skills: React, TypeScript, Next.js, SSR, SSG, CSR, JavaScript, LLM, AI, CoreWebVitals, Accessibility, Security, Localization, SemanticSearch, GraphQL 🏢 Description: Senior Frontend Engineer (React) 💰 Salary: $8000-$12,000 🕦 Full-time ☑️ B2B 🌴 Hybrid We are looking for a Senior Frontend Engineer to join a fast-growing AI product company's engineering team. The role sits at the crossroads of frontend architecture and product experience, owning both the delivery of business-critical Next.js applications and the design of intuitive, trustworthy user experiences for agentic AI products. Requirements Over 5 years of frontend engineering experience, including 3+ years specializing in React and modern TypeScript. Production Next.js experience: SSR applications at scale, app router, server components, and the trade-offs between SSR, SSG, and CSR. Complex state management for hard scenarios: real-time collaboration, optimistic updates, multi-tenant isolation, large-scale data sync. Experience building AI/LLM interfaces: streaming token responses, chat UIs, semantic search, or similar real-time AI interactions. High-load performance work: you monitor Core Web Vitals and know how to improve them under heavy traffic and large datasets. Enterprise application depth: localization, accessibility, security, and compliance, you understand the complexity beyond "making it work". A security-conscious approach to engineering: you handle sensitive data carefully and think about the security implications of what you ship. Strong craft and product instinct: you don't wait for perfect designs, you spot UX issues and propose solutions, and you're never satisfied with "good enough". AI-native working style. You already use AI coding agents daily and are eager to push the boundaries of harness engineering. Clear communication. You articulate design decisions and technical trade-offs clearly, verbally and in writing. Key Responsibilities Design and ship production Next.js SSR applications with complex state, high-load scenarios, and real-time AI interactions at scale. Build interfaces for AI-powered features: streaming LLM responses, semantic search across millions of documents, interactive knowledge graphs, and agentic builders. Architect component libraries and maintain the design system, ensuring reusability, accessibility, and consistent UX across the platform. Deliver enterprise-grade functionality: localization, accessibility compliance, cross-browser support, and security. Take full ownership after launch: monitor performance in production, optimize bundle sizes, instrument for Core Web Vitals, and ensure things scale gracefully. Keep the bar high on code quality, testing, and craft through thoughtful code review and mentorship.

🏢 Summary: Senior Frontend Developer role focused on building and enhancing modern React-based applications for the insurance sector within an international agile team. The position involves developing scalable frontend solutions, integrating with REST APIs, ensuring code quality through testing, and mentoring junior developers. The offer targets experienced engineers ready to contribute to large, international projects using modern technologies. 🗂️ Requirements: Minimum 5 years of experience as Frontend Developer, Strong knowledge of React, Strong knowledge of TypeScript, Proficiency in JavaScript ES6+, Knowledge of SCSS, HTML5, CSS3, Experience with UI frameworks, Experience with REST API integration, Experience in unit testing, Knowledge of Git, Basic knowledge of SQL and databases, Experience working in Agile/Scrum 📃 Skills: React, TypeScript, JavaScript, SCSS, HTML5, CSS3, Bootstrap, MaterialUI, REST, Git, SQL, Agile 🏢 Description: Opis stanowiska: Poszukujemy doświadczonego Senior Frontend Developera specjalizującego się w React, który dołączy do zespołu realizującego projekty dla branży ubezpieczeniowej. Osoba na tym stanowisku będzie odpowiedzialna za rozwój nowoczesnych aplikacji frontendowych oraz współpracę z międzynarodowym zespołem w środowisku agile. Zakres obowiązków: Tworzenie i rozwój aplikacji frontendowych w oparciu o React i TypeScript Analiza wymagań biznesowych i ich przekładanie na rozwiązania techniczne Współpraca z zespołem projektowym (developerzy, testerzy, analitycy) Integracja z usługami REST API Pisanie testów jednostkowych i dbanie o jakość kodu Debugowanie oraz optymalizacja istniejących rozwiązań Wsparcie i mentoring dla mniej doświadczonych członków zespołu Wymagania: Minimum 5 lat doświadczenia na stanowisku Frontend Developera – warunek konieczny Bardzo dobra znajomość React oraz TypeScript Dobra znajomość: JavaScript ES6+, SCSS, HTML5, CSS3 Doświadczenie z frameworkami UI (Bootstrap, Material UI lub podobne) Praktyczna znajomość integracji z REST API Doświadczenie w pisaniu testów jednostkowych Znajomość Git Podstawowa znajomość SQL i pracy z bazami danych Doświadczenie w pracy w metodykach Agile/Scrum Bardzo dobra znajomość języka angielskiego (min. B2) Mile widziane: Doświadczenie z architekturą mikroserwisową Znajomość Vue.js Certyfikaty technologiczne (React, Java, Spring, SQL, AWS, Azure) Doświadczenie w projektach międzynarodowych Znajomość języka niemieckiego lub innego języka europejskiego Oferujemy: Pracę przy dużych, międzynarodowych projektach Elastyczny model pracy Konkurencyjne wynagrodzenie Możliwość rozwoju i pracy z nowoczesnymi technologiami

🏢 Summary: Senior/Lead Frontend Developer role focused on designing and developing modern web applications using Angular (preferred) or React. The position involves owning frontend architecture, making technical decisions, and ensuring high code quality and best practices. You will collaborate closely with backend and product teams to deliver scalable and high-performance solutions. 🗂️ Requirements: Strong commercial experience as Senior Frontend Developer, Proficiency in Angular or React, Very good knowledge of JavaScript and TypeScript, Very good knowledge of HTML5 and CSS, Experience in state management, Experience in component architecture design, Knowledge of performance optimization, Knowledge of WCAG and accessibility standards, Experience in frontend-backend integration via API, Experience with CI/CD pipelines, Experience with code review and automated testing, Experience in designing scalable and modular frontend architectures 📃 Skills: Angular, React, JavaScript, TypeScript, HTML5, CSS, API, CI/CD, WCAG, Testing, Performance, StateManagement, ComponentArchitecture, CodeReview 🏢 Description: Poszukujemy Frontend Developera (Senior / Lead) z doświadczeniem w Angular lub React, który wesprze nasz zespół w tworzeniu i rozwijaniu nowoczesnych aplikacji webowych. Szukamy osoby, która nie tylko świetnie odnajduje się w kodzie, ale również chce mieć realny wpływ na decyzje techniczne, architekturę oraz kierunek rozwoju front-endu. Jeśli lubisz dzielić się wiedzą, angażować się w dyskusje i podejmować wyzwania - ta rola jest dla Ciebie. Pracując na tym stanowisku będziesz: Odpowiadać za architekturę oraz rozwój warstwy front-endowej w projekcie Brać aktywny udział w dyskusjach technicznych i podejmowaniu decyzji Wspierać i mentorować innych programistów Dbać o wysoką jakość kodu, jego strukturę oraz stosowanie najlepszych praktyk Współpracować z zespołami back-end, architektury oraz produktu Uczestniczyć w uzgodnieniach technicznych i wspierać spójność całego rozwiązania Szukamy właśnie Ciebie, jeśli: Posiadasz solidne doświadczenie jako Frontend Developer (Senior) Pracujesz z nowoczesnymi frameworkami (Angular - preferowany lub React) Bardzo dobrze znasz JavaScript / TypeScript, HTML5 oraz CSS Masz doświadczenie w zarządzaniu stanem i projektowaniu architektury komponentów Rozumiesz aspekty wydajności, dostępności (WCAG) i użyteczności aplikacji Potrafisz podejmować decyzje techniczne i proponować rozwiązania Dobrze rozumiesz współpracę front-endu z back-endem (API, kontrakty) Znasz nowoczesne procesy wytwarzania oprogramowania (CI/CD, code review, testy) Jesteś samodzielny/a, proaktywny/a i dobrze zorganizowany/a Masz doświadczenie w mentoringu lub chcesz rozwijać się w kierunku liderskim Posiadasz znajomość języka angielskiego na poziomie B2/C1 Idealnie, jeśli dodatkowo: Masz doświadczenie w projektowaniu skalowalnych, modułowych architektur front-endowych Czujesz się komfortowo w roli lidera technicznego lub chcesz ją pełnić Masz doświadczenie w koordynacji technicznej lub pracy przekrojowej między zespołami Warto do nas dołączyć, bo: Będziesz mieć realny wpływ na kierunek rozwoju projektu i architektury Pracujesz w doświadczonym zespole, który ceni współpracę i dzielenie się wiedzą Używamy nowoczesnego stosu technologicznego i zwinnych metod pracy Masz przestrzeń do rozwoju, mentoringu i podejmowania inicjatywy Tworzymy środowisko, w którym liczy się jakość, odpowiedzialność i dobra komunikacja

🏢 Summary: Senior React Developer role in the banking sector focused on delivering scalable, high-quality front-end and platform solutions. The position involves building and maintaining reusable components, ensuring accessibility compliance, and implementing comprehensive unit and e2e testing. The developer will also support other teams with front-end best practices and technical expertise. 🗂️ Requirements: Minimum 5 years of professional experience, Experience in banking or financial sector, Very good knowledge of React, Very good knowledge of JavaScript, Very good knowledge of TypeScript, Very good knowledge of CSS, Experience in building scalable front-end applications, Experience in creating and maintaining NPM packages, Strong knowledge of unit testing, Strong knowledge of e2e testing, Ability to write and refactor tests using Jest, Testing Library, Cypress, Proficiency with Git, Knowledge of Accessibility (a11y) principles, Ability to build interfaces compliant with WCAG, Experience with Jira, Experience with Confluence, Experience with Bitbucket 📃 Skills: React, JavaScript, TypeScript, CSS, NPM, Jest, TestingLibrary, Cypress, Git, WCAG, Accessibility, Jira, Confluence, Bitbucket 🏢 Description: umowa: B2B stawka: 185 zł/h + VAT tryb: hybryda, 1 dzień w tygodniu (środa) z biura w Warszawie branża: bankowość Poszukujemy Senior React Developera, który posiada bardzo dobrą znajomość technologii webowych oraz umiejętność współpracy w zespole. Wymagana jest biegłość w React, JavaScript, TypeScript oraz CSS, a także znajomość testów jednostkowych i dobrych praktyk w zakresie dostępności. Idealny kandydat to osoba, która potrafi dostarczać wysokiej jakości rozwiązania techniczne oraz wspierać inne zespoły. Główne obowiązki Dostarczanie generycznych i platformowych rozwiązań dla zespołów front-endowych. Pisanie i utrzymanie testów jednostkowych oraz e2e. Dbanie o spójność i wysoką jakość dostarczanych rozwiązań. Naprawa błędów. Współpraca z innymi zespołami platformowymi i projektantami. Wsparcie merytoryczne zespołów w ramach szeroko rozumianego front-endu. Tworzenie i utrzymywanie dokumentacji. Kluczowe wymagania Minimum 5 lat doświadczenia zawodowego. Doświadczenie w sektorze bankowym/finansowym. Bardzo dobra znajomość React, JavaScript, TypeScript, NPM oraz CSS. Doświadczenie w tworzeniu i utrzymywaniu skalowalnych aplikacji front-endowych oraz paczek NPM. Bardzo dobra znajomość testów jednostkowych oraz e2e. Umiejętność samodzielnego pisania, utrzymywania i refaktoryzacji testów (np. Jest, Testing Library, Cypress). Biegła obsługa systemu kontroli wersji Git. Dobre rozumienie zasad dostępności (Accessibility / a11y). Umiejętność tworzenia interfejsów zgodnych z WCAG. Doświadczenie z pracą z Jira, Confluence, Bitbucket. Umiejętności mile widziane Doświadczenie w pracy z design systemami, zarówno w ich używaniu, jak i współtworzeniu we współpracy z zespołem projektowym. Doświadczenie w architekturze microfrontendów. Znajomość wyzwań związanych z podziałem aplikacji i integracją. Doświadczenie w pracy z hybrydowymi aplikacjami mobilnymi (np. WebView, React Native). Doświadczenie w pracy z agentami AI lub narzędziami opartymi o AI.

🏢 Summary: Full-time Team Lead Software Engineer role focused on leading a full-stack team building high-performance web applications using React and Node.js. The position combines hands-on development with architectural ownership, mentoring, and delivery of scalable, AI-powered enterprise platforms. Work involves designing microservices, APIs, and cloud-based containerized deployments in a hybrid setup from Warsaw. 🗂️ Requirements: 7+ years full-stack experience with React.js and Node.js in production, 2+ years in Team Lead or senior engineering leadership role, Strong knowledge of React ecosystem (Redux, Hooks, component architecture, performance optimization), Proficiency in HTML5, CSS3, JavaScript ES6+, Experience with build tools (Webpack, Vite, or Babel), Experience with Express.js and RESTful API design, Knowledge of OAuth, JWT, session-based authentication, Experience with PostgreSQL or MySQL, Experience with MongoDB or other NoSQL databases, Hands-on experience with Docker, Familiarity with AWS or other major cloud platform, Experience with Git and Agile/Scrum methodologies 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, REST, GraphQL, OAuth, JWT, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Git, Webpack, Vite, Babel, Agile, Scrum 🏢 Description: 💰 Salary: 29,500–33,200 PLN/month 🌎 Hybrid from Warsaw, Poland 🕦 Full-time position, long-term ☑️ Contract of Employment We are looking for a Team Lead Software Engineer to join our client, a technology company that builds AI-powered platforms and consulting solutions for enterprise operations, with a strong focus on the private capital sector. The company has over ten years of experience working with high-growth and PE-backed businesses, combining deep domain expertise with advanced technology to drive measurable results. In this role, the focus will be on leading a team of developers across front-end and back-end development, owning architectural decisions, and contributing directly to the codebase. You will mentor engineers and drive the delivery of high-performance web applications using React and Node.js. Requirements 7+ years of full-stack development experience with React.js and Node.js in production environments 2+ years in a team lead, tech lead, or senior engineering leadership role Strong command of the React ecosystem: Redux, React Hooks, component architecture, and performance optimization Solid HTML5, CSS3, and modern JavaScript (ES6+); experience with build tooling such as Webpack, Vite, or Babel Proficiency with Express.js and API design (RESTful; GraphQL is a plus) Working knowledge of auth patterns: OAuth, JWT, session-based authentication Hands-on experience with PostgreSQL or MySQL; familiarity with MongoDB or similar NoSQL databases Docker experience required; Kubernetes is a plus Familiarity with at least one major cloud platform (AWS preferred) Comfortable with Git workflows and Agile/Scrum delivery Responsibilities Lead and mentor a team of software engineers; run code reviews, set engineering standards, and hold the bar on quality Architect and build full-stack features using React.js (with Redux and Hooks) on the front end and Node.js / Express.js on the back end Design scalable microservices and RESTful (or GraphQL) APIs aligned with product requirements Own the testing strategy: define coverage expectations, enforce unit and integration testing, and integrate quality gates into CI/CD pipelines Manage containerized deployments via Docker; collaborate on infrastructure with cloud platforms (AWS, Azure, or GCP) Partner directly with Product and Design to translate requirements into production-grade, accessible interfaces Model and maintain SQL and NoSQL data schemas; own data interaction patterns across services Monitor production systems, triage incidents, and drive root-cause resolution Keep technical documentation accurate and up to date Get to know DevsData We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team. We employ people with experience in international corporations as well as the ones from the best technical and business universities. Find out more: https://devsdata.com