{"id":2688924,"url":"https://alion.io/job/itds-poland-senior-fullstack-developer-net-react-2","title":"Senior Fullstack Developer (.NET & React)","company":{"id":879,"name":"ITDS Poland","domain":"itds.pl","url":"https://alion.io/company/itds","size_band":"201-500","is_staffing_agency":false,"employer_type":"staffing","is_intermediary":false,"listed_via":null,"ats_vendor":null,"truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"contractor","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Warsaw, Poland","Poland"],"countries":["PL"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":18900,"max":24150,"currency":"PLN","period":"month","gross":null,"usd_annual":74340},"salary_estimate":null,"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":".NET","optional":false},{"name":"Agile","optional":false},{"name":"C#","optional":false},{"name":"Playwright","optional":false},{"name":"Postman","optional":false},{"name":"Scrum","optional":false},{"name":"SQL","optional":false}],"status":"closed","first_seen_at":"2026-10-16T08:20:17Z","employer_posted_date":null,"last_verified_at":"2026-10-22T20:25:00Z","board_verified":false,"closed_at":"2026-10-22T20:25:00Z","days_open":6,"trust":{"level":"not_scored","repost_count":null,"flags":[],"days_open":6},"description":"Ignite innovation with transformative full-stack solutions — shape the future of software engineering!\nWarszawa/ Gdańsk - based opportunity with hybrid work model(1 day/ week in the office).\nAs a Senior Fullstack Developer (.NET & React), you will be working for our client, a leader in the technology sector dedicated to developing scalable and efficient software solutions. You will contribute to creating cutting-edge applications that drive digital transformation and provide impactful user experiences. This role offers a unique chance to grow your career amidst a forward-thinking team that values innovation and excellence.\nYour main responsibilities:\nDevelop high-quality software in C# ensuring adherence to technical documentation.\nImplement front-end features using React (18 and above) to deliver dynamic user interfaces.\nAnalyze and enhance existing legacy code bases, ensuring consistent performance.\nDesign and develop robust application architectures aligned with best practices.\nCollaborate closely with testers, analysts, and product owners within Agile (SCRUM) methodologies.\nConduct debugging, profiling, and performance analysis to optimize application efficiency.\nApply principles of DDD, Clean Code, and SOLID to maintain code quality and scalability.\nWork with TSQL and SQL Management Studio to develop and optimize database interactions.\nYou are ideal for this role if you have:\nAt least 5 years of experience in developing .NET applications.\nA minimum of 3 years in React-based front-end development.\nStrong knowledge of C# (.NET Framework, .NET Standard, .NET Core).\nSkilled in debugging, performance profiling, and analyzing complex code.\nProficiency in architectural patterns, asynchronous communication, and software design.\nExperience with TSQL and SQL Server Management Studio.\nFamiliarity with Visual Studio.\nIt is a strong plus if you have:\nExperience building views for mobile applications.\nBackground developing applications for the financial industry.\nAutomation testing experience with tools like Postman or PlayWright.\nKnowledge of WCAG standards.\nLanguage Required for the role:\nPolish (bilingual proficiency)\nEnglish (communicative level, minimum B2)\nEligibility to work in Europe:\nOnly candidates with an existing legal right to work in the European Union will be considered for this role.\n#MAKEYourCareerBETTER\nInterested? 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.\nTech stack\nC# / .NET\nReact\nSQL / TSQL\nSoftware Architecture\nDDD / SOLID / Clean Code\nDebugging & Performance Profiling\nAgile / Scrum\nMobile Application Development\nAutomation Testing (Postman / Playwright)\nWCAG Standards","description_format":"text","description_chars":2740,"description_truncated":false,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Hybrid work"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["IT Consulting & Digital Transformation","IT Staffing & Staff Augmentation"],"lifecycle":[{"event":"open","at":"2026-10-16T08:25:15Z"},{"event":"close","at":"2026-10-22T20:25:00Z"}],"visa":[],"liveness":null,"pay":{"stated_usd_annual":74340,"is_top_pay":false},"html_url":"https://alion.io/job/itds-poland-senior-fullstack-developer-net-react-2","json_url":"https://alion.io/job/itds-poland-senior-fullstack-developer-net-react-2.json","meta":{"generated_at":"2026-10-23T13:26:44Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":20074,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-24T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":879},"rest":"https://alion.io/mcp/rest/get_company?id=879"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fitds-poland-senior-fullstack-developer-net-react-2"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fitds-poland-senior-fullstack-developer-net-react-2"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fitds-poland-senior-fullstack-developer-net-react-2"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/itds-poland-senior-fullstack-developer-net-react-2\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fitds-poland-senior-fullstack-developer-net-react-2"}]}