June 30, 2026
Senior Backend/Fullstack Developer
Senior • Remote
Lisbon, Portugal
Summary: The role of Senior Backend/Fullstack Developer is crucial for the evolution, an enterprise application that aids municipalities in managing waste collection and environmental services. This role focuses on solving complex technical problems and improving existing software rather than just creating new applications.
Responsibilities:
Develop and maintain a large-scale enterprise application built with C# and .NET.
Troubleshoot and resolve complex production issues across the platform.
Analyse existing solutions and improve maintainability through refactoring.
Improve application performance and optimise database queries.
Develop backend services and REST APIs.
Work with PostgreSQL using both raw SQL and Entity Framework.
Contribute to architecture discussions and technical decision-making.
Write clean, maintainable and well-tested code.
Implement Unit Tests and Integration Tests.
Participate actively in Scrum ceremonies, refinement sessions and technical discussions.
Contribute to continuous improvement initiatives across the development lifecycle.
Help identify opportunities to leverage AI-assisted software development tools to improve engineering efficiency.
Key Requirements:
8+ years of professional software development experience.
Strong experience with C# and .NET (both .NET Framework and modern .NET).
Solid understanding of enterprise backend development.
Extensive experience debugging complex production systems.
Experience working with legacy and monolithic applications.
Strong SQL skills, including writing, analysing and optimising raw SQL queries.
Experience with PostgreSQL or other relational databases.
Experience using Entity Framework or similar ORM technologies.
Experience designing and consuming REST APIs.
Experience with Git, GitHub and CI/CD pipelines.
Experience writing Unit Tests and Integration Tests.
Good understanding of Agile methodologies (Scrum).
Ability to work independently and proactively.
Excellent English communication skills.
Nice to Have:
Experience with waste management systems.
Experience in public sector software.
Knowledge of utilities or environmental platforms.
Understanding of SOLID principles.
Experience in software architecture.
Skills in performance optimisation.
Familiarity with security best practices.
Knowledge of domain-driven design.
Experience with GitHub Copilot and AI-assisted software development.
Understanding of process optimisation.
Experience in technical mentoring.
Other Details:
Technical Environment: Includes C#, .NET, ASP.NET, PostgreSQL, REST APIs, Git/GitHub, CI/CD.
Initial Onboarding: In the first three months, the developer will learn the RenoWeb platform, work independently on bug fixes, and deliver small tasks, with expectations of becoming largely autonomous by the end of the onboarding period.
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Kraków, Poland
160 - 270 PLN/hr
🏢 Summary: Senior Full Stack Developer role focused on building an enterprise AI agent management platform, with strong emphasis on backend development in Python. The position involves developing scalable web applications using Python and React, designing architecture, building REST APIs, and working on authentication and SSO integrations. The role includes collaboration on technical decisions, mentoring developers, and contributing to production-grade enterprise solutions. 🗂️ Requirements: 5+ years of commercial development experience, Strong Python knowledge, Commercial experience with React, Experience building web applications, Experience with Django, FastAPI or similar frameworks, Experience designing software architecture, Experience building scalable applications, Experience working with production systems, Practical knowledge of REST API, Knowledge of authentication and authorization, English level B2 or higher 📃 Skills: Python, React, Django, FastAPI, Celery, Docker, REST, SSO, API, Microservices 🏢 Description: O projekcie Projekt dotyczy budowy rozwiązania wspierającego organizacje enterprise we wdrażaniu i zarządzaniu agentami AI. Produkt rozwijany jest we współpracy z klientami enterprise i odpowiada na rzeczywiste potrzeby biznesowe. O roli Poszukujemy Senior Full Stack Developera, który dołączy do zespołu rozwijającego aplikację webową dla klientów enterprise. Jest to rola Full Stack z wyraźnym naciskiem na rozwój backendu w Pythonie. Będziesz rozwijać zarówno backend, jak i frontend aplikacji, uczestniczyć w projektowaniu rozwiązań oraz brać udział w decyzjach architektonicznych. Zakres obowiązków rozwój aplikacji webowej z wykorzystaniem Pythona i React, projektowanie i rozwój backendu, rozwój komponentów frontendowych w React, rozwój REST API, rozwój i utrzymanie aplikacji produkcyjnych, projektowanie skalowalnych rozwiązań dla klientów enterprise, praca nad authentication, authorization i integracjami SSO, udział w decyzjach architektonicznych oraz proponowanie rozwiązań, udział w code review i design sessions, współpraca z zespołem przy podejmowaniu decyzji technicznych, wspieranie mniej doświadczonych programistów poprzez dzielenie się wiedzą. Stack technologiczny Python React Django Celery Docker Czego oczekujemy 5 lat lub więcej doświadczenia komercyjnego, bardzo dobrej znajomości Pythona, komercyjnego doświadczenia z React, doświadczenia w tworzeniu aplikacji webowych, doświadczenia z Django, FastAPI lub podobnym frameworkiem, doświadczenia w projektowaniu architektury oprogramowania, doświadczenia w budowaniu skalowalnych aplikacji, doświadczenia w pracy z systemami produkcyjnymi, praktycznej znajomości REST API, znajomości zagadnień związanych z authentication i authorization, bardzo dobrej komunikacji, języka angielskiego na poziomie minimum B2. Dodatkowym atutem będzie doświadczenie z aplikacjami enterprise, znajomość SSO lub federated identity, doświadczenie w tworzeniu Python SDK, doświadczenie z architekturą opartą o API lub mikroserwisy. Model pracy praca w modelu hybrydowym w Krakowie, preferowane 1–3 dni w tygodniu w biurze (możliwe jest indywidualne ustalenie liczby dni). Oferujemy wynagrodzenie: 160–270 PLN/h, współpracę w oparciu o B2B, długoterminową współpracę, realny wpływ na architekturę i rozwiązania techniczne, pracę nad produktem dla klientów enterprise, pracę nad produktem wykorzystującym rozwiązania AI. Proces rekrutacyjny Rozmowa z rekruterem. Rozmowa Cultural Fit. Rozmowa techniczna. Decyzja. Proces nie obejmuje zadania domowego ani live codingu.