{"id":142400,"url":"https://alion.io/job/moss-senior-backend-engineer-fmd","title":"Senior Backend Engineer (f/m/d)","company":{"id":51797,"name":"Moss","domain":"getmoss.com","url":"https://alion.io/company/moss","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"A","score":86,"open_postings":11,"ghost_share":0,"stale_share":0.364,"repost_share":0,"time_to_fill_p50_days":80,"computed_at":"2026-10-17T05:46:00Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Warsaw, Poland"],"countries":["PL"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":59000,"max_usd":99000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":339},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Flink","optional":false},{"name":"Java","optional":false},{"name":"n8n","optional":false},{"name":"Rest API","optional":false},{"name":"Spring Framework","optional":false}],"status":"live","first_seen_at":"2026-07-13T08:50:52Z","employer_posted_date":"2026-07-13","last_verified_at":"2026-10-18T15:33:55Z","board_verified":true,"closed_at":null,"days_open":97,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":97},"description":"At Moss, we give finance professionals the power to automate their day-to-day and make forward-thinking decisions.\nOur culture is what makes that possible: we play to win, we obsess over quality, and we win as One Moss, and it works. Moss closed a €35 million Series C in August 2026, crossing a €1 billion valuation, and became one of Europe's fintech unicorns. Join us for what's next.\nWe are looking for Senior Backend Engineers (f/m/d) for a variety tribes in Warsaw.\nCollaborating closely with designers, product managers and frontend engineers, you will bring innovative ideas to life, helping us build the Finance AI platform for Europe's mid-sized businesses.\nYour responsibilities\nHere's a bit more on what you can expect to be doing day-to-day:\nBackend Development: Lead the development of the application, ensuring it aligns with the product requirements and meets performance and usability standards. Proactively provide regular updates on work progress, achievements and challenges to product managers (PMs) and designers.\n\nCollaborative Planning: Partner with PMs and designers during project kick-offs to gain a comprehensive understanding of the overall vision, user needs, and goals. Provide valuable insights to refine UI/UX concepts and contribute to the planning of backend development.\n\nFrontend Collaboration: Collaborate closely with frontend engineers to determine required APIs and frontend functionality. Maintain clear communication channels to ensure smooth integration of frontend and backend components.\n\nTesting and Quality Assurance: Produce well tested and reliable code. Writing unit and functional (end-to-end) tests.\n\nRollout and Performance Monitoring: Collaborate with product managers to devise efficient rollout strategies for new features. Monitor performance and user feedback to identify areas for improvement and proactively address potential issues.\n\nAbout you\nWe think you’ll need the following experience and qualifications to succeed in this role:\nProven experience as a Backend Engineer, leading projects end-to-end to launch.\n\nProficiency in Java development technologies (incl. Spring framework), as well as latest features and best practices such as microservices, message queue, alerting, reliability and feature flags.\n\nUnderstanding of development design patterns and techniques, incl. Rest API design principles.\n\nHands-on experience with testing approaches and libraries (unit testing, integration testing).\n\nYou are fluent in English.\n\nIn addition, here are the skills and attributes we are looking for:\nPragmatic Tech Enthusiast: You have the theoretical and practical background to engineer our product. You pursue quality and scalability and follow industry and company best practices. You build systems that are easy to maintain and to understand by others.\n\nDelivery Focused: You understand and focus on what is important to deliver the most impact. This means accurate development and delivery estimations, ruthless prioritization and saying no to less important things. You are driven to deliver tangible outcomes within estimated timelines, and you swiftly tackle challenges, and provide clear direction to others.\n\nCollaborative Communicator: You convey information effectively to a variety of audiences, and actively participate in daily meetings, keeping others informed about your progress and status. You’re able to form trustworthy connections by creating and maintaining open communication with colleagues throughout the development process.\n\nInquisitive Mindset: You’re detail-oriented and seek to develop a deep domain knowledge by proactively seeking to understand workflows and technical intricacies. You’re curious and unafraid to question assumptions and propose alternative approaches, ensuring the product is tailored to meet customer needs.\n\nTeam Player: You bring a team together to work towards a shared goal, as well as support individuals throughout all phases of a project.\n\nAbout Moss\nMoss is the Finance AI platform for Europe's mid-sized businesses, giving companies real-time visibility and full control over their spend. By automating card issuing, invoice management and expenses, Moss simplifies financial workflows and frees finance and accounting teams from manual, administrative work.\nFounded in Berlin and used by more than 10,000 businesses including Flink, Schufa, n8n and Auto1, Moss has raised €220+ million to date and operates in Germany, the Netherlands, the UK and further EU markets. In August 2026, Moss closed a €35 million Series C led by Portage, crossing a €1 billion valuation and becoming one of Europe's newest fintech unicorns. Moss is backed by investors including Valar Ventures, Tiger Global, Global Founders Capital, Cherry Ventures, A-Star.\nWe're a team of 300+ people from 50+ nationalities across 5 offices in Europe and we hire, reward, and grow people based on Moss DNA: playing to win, obsessing over quality, winning as One Moss. If that's how you want to work, we want to hear from you. - here's what else to expect:\nTop-of-market compensation package, including equity.\n\nOur vibrant offices are at the heart of our culture, where in-person time fuels collaboration and connection over weekly breakfasts and Friday demos.\n\nAdditional benefits include: 20 days “work from abroad”, 600EUR/GBP Learning & Development Budget, and other local benefits.\n\nUnless stated otherwise, benefits apply to full-time positions (interns and working students receive a tailored package).\nBy applying for the above position, you will confirm that you have reviewed and agreed to ourData Privacy Policy .","description_format":"text","description_chars":5614,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[{"language":"English","level":"Advanced (C1)","optional":false}]},"benefits":["Equity"],"hiring_locations":[{"name":"Poland","iso":"PL","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Cards & Card Issuing","Procurement & Spend Management"],"lifecycle":[{"event":"open","at":"2026-07-13T08:50:52Z"}],"visa":[],"liveness":{"score":31,"band":"fade","label":"Fading","p_open":1,"p_active":0.711,"p_room":0.44,"age_days":95,"expected_fill_days":80,"reasons":["conf:2","win:tail","crowd:"],"computed_at":"2026-10-17T05:46:00Z"},"pay":null,"html_url":"https://alion.io/job/moss-senior-backend-engineer-fmd","json_url":"https://alion.io/job/moss-senior-backend-engineer-fmd.json","meta":{"generated_at":"2026-10-18T15:40:15Z","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":21582,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-19T00:00:00Z"}},"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":51797},"rest":"https://alion.io/mcp/rest/get_company?id=51797"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fmoss-senior-backend-engineer-fmd"},{"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%2Fmoss-senior-backend-engineer-fmd"},{"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%2Fmoss-senior-backend-engineer-fmd"},{"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/moss-senior-backend-engineer-fmd\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fmoss-senior-backend-engineer-fmd"}]}