{"id":2823662,"url":"https://alion.io/job/3ap-senior-backend-developer","title":"Senior Backend Developer","company":{"id":20630,"name":"3Ap","domain":"3ap.ch","url":"https://alion.io/company/3ap","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"BambooHR","truth_index":{"grade":"B","score":83,"open_postings":3,"ghost_share":0,"stale_share":0.667,"repost_share":0,"time_to_fill_p50_days":41,"computed_at":"2026-10-31T05:58:55Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Belgrade, Serbia"],"countries":["RS"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Angular","optional":false},{"name":"CI/CD","optional":false},{"name":"Claude","optional":false},{"name":"Copilot","optional":false},{"name":"Docker","optional":false},{"name":"Insomnia","optional":false},{"name":"Java","optional":false},{"name":"Jenkins","optional":false},{"name":"Kubernetes","optional":false},{"name":"Node JS","optional":false},{"name":"OpenShift","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Postman","optional":false},{"name":"Prompt Engineering","optional":false},{"name":"Python","optional":false},{"name":"React.js","optional":false},{"name":"Rest API","optional":false},{"name":"Vue.js","optional":false},{"name":"JavaScript","optional":true},{"name":"TypeScript","optional":true}],"status":"live","first_seen_at":"2026-04-21T00:00:00Z","employer_posted_date":"2026-04-21","last_verified_at":"2026-10-31T06:03:19Z","board_verified":true,"closed_at":null,"days_open":193,"trust":{"level":"stale","repost_count":1,"flags":["stale"],"days_open":193},"description":"Senior Backend Developer, Serbia\nWe’re looking for a Senior Backend Developer who challenges assumptions, builds with intention, and thrives in a fast-moving, AI-driven environment.\nAt 3ap, engineers own their work end-to-end. Our teams run on separate projects but solve hard problems together, share what they learn, and call out bad assumptions, including their own.\nWhat we need:\n5+ years with Java/Spring\nSolid REST API design and integration experience\nHands-on with Docker, Kubernetes, Jenkins, and OpenShift\nRigorous about testing, especially where AI outputs are involved\nComfortable with API tools like Postman or Insomnia\nYou think about the full product, not just your layer. A bad integration can sink a good solution\nYou don’t stop at “it works.” You look for the flaw in the logic before someone else finds it in production\nYou pick up new tools fast. The AI landscape shifts week to week, and waiting to learn something familiar isn’t an option\nYou treat AI output as a draft, not a deliverable. You build guardrails, test rigorously, and verify manually\nYou’ve used GitHub Copilot, Claude, or similar in your actual workflow\nYou communicate clearly and don’t need much hand-holding to unblock yourself\nUniversity degree in CS or equivalent\nFluent English\nUseful, but not required:\nWebFlux / reactive programming\nNode.js, PostgreSQL, MongoDB, React, Angular, or Vue\nCI/CD and DevOps hands-on experience\nPrompt engineering or multi-step AI workflows\nComfort and openness to working with Python. Many modern AI tools and frameworks are built with Python at their core, so a willingness to learn and use it is important.\nBackground in insurance or finance\nAny German\nWhat you get:\nA team of 50+ professionals in a people-first culture, flat structure, and no bureaucracy\nWork that uses current technology, including AI in production\nFlexible hours, hybrid work\n25 vacation days + 2 extra 3ap holidays\nPrivate pension, private health insurance, 24/7 accident insurance\nMaternity and paternity leave support\nTeam events and an employee referral program","description_format":"text","description_chars":2063,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[{"language":"English","level":"Advanced (C1)","optional":false}]},"benefits":["Health insurance","Hybrid work"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["IT Consulting & Digital Transformation","Custom Software Development"],"lifecycle":[{"event":"open","at":"2026-10-18T19:40:27Z"},{"event":"reopen","at":"2026-10-23T22:50:02Z"}],"visa":[],"liveness":{"score":9,"band":"cold","label":"Long shot","p_open":1,"p_active":0.33,"p_room":0.28,"age_days":193,"expected_fill_days":41,"reasons":["conf:4","win:tail","crowd:"],"computed_at":"2026-10-31T05:58:55Z"},"pay":null,"html_url":"https://alion.io/job/3ap-senior-backend-developer","json_url":"https://alion.io/job/3ap-senior-backend-developer.json","meta":{"generated_at":"2026-10-31T07:37:19Z","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":11332,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-01T00:00:00Z"}},"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":20630},"rest":"https://alion.io/mcp/rest/get_company?id=20630"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2F3ap-senior-backend-developer"},{"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%2F3ap-senior-backend-developer"},{"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%2F3ap-senior-backend-developer"},{"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/3ap-senior-backend-developer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2F3ap-senior-backend-developer"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":2823662}},{"tool":"search_jobs","arguments":{"company":"3ap.ch","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":2823662},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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