{"id":2943444,"url":"https://alion.io/job/supercharge-senior-javakotlin-engineer-freelancer","title":"Senior Java/Kotlin Engineer (Freelancer)","company":{"id":55006,"name":"Supercharge","domain":"supercharge.io","url":"https://alion.io/company/supercharge","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Lever","truth_index":{"grade":"B","score":75,"open_postings":3,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-10-25T05:49:26Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"freelance","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Budapest, Hungary"],"countries":["HU"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":47000,"max_usd":84000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":18},"experience_years_min":3,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AWS","optional":false},{"name":"Grafana","optional":false},{"name":"Helm","optional":false},{"name":"Java","optional":false},{"name":"Kotlin","optional":false},{"name":"Kubernetes","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Redis","optional":false},{"name":"Spring Boot","optional":false},{"name":"SQL","optional":false},{"name":"Terraform","optional":false}],"status":"live","first_seen_at":"2026-10-20T14:20:32Z","employer_posted_date":"2026-10-20","last_verified_at":"2026-10-25T18:21:44Z","board_verified":true,"closed_at":null,"days_open":5,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":5},"description":"We’re looking for a Senior Java/Kotlin Freelancer with at least 3 years of Kotlin backend development experience to join a renewable energy trading project. The solution connects asset data and trading operations on a single platform, enabling end-to-end automation across forecasting, trading, and dispatch.\nYou’ll work with Kotlin and Spring Boot in a full Supercharge project, with design, project management, architecture, and tech leadership provided in-house. The team works in Hungarian, while specifications are in English, and there is no direct client interaction.\nThe project runs full-time (40 hours/week) for approximately 3 months, with an expected start in mid-November. On-site presence is required once a week at our Budapest office (Czuczor utca 2., 3rd floor), with additional days possible if needed.\nYou can expect a high-quality engineering environment focused on clean code, modern technologies, a strong team, and a friendly atmosphere.\nYour day to day will include:\nSupporting the development of a stable and scalable Kotlin and Spring Boot back-end from the ground up\nCrafting code that adheres to the highest industry standards while ensuring seamless integration with our Cl tools\nCollaborating effectively within a dynamic team environment on exciting, cutting-edge tech initiatives while working closely with fellow engineers and supporting Tech Leads and Architects\nBringing an architectural perspective to the planning process\nWhat makes you thrive here:\n3+ years of experience in Java ecosystem, familiarity with Java 17, 21\nDeep understanding of Spring Boot\nExperience with an observability platform (Grafana / LGTM or ELK stack or NewRelic)\nProven ability to troubleshoot under pressure, quickly identify root causes, recommend impactful solutions, and ensure thorough follow-through\nHands-on experience with SQL or NoSQL databases (Postgres, Redis)\nExperience with Kubernetes\nFamiliarity with at least one public cloud provider (preferably AWS)\nFamiliarity with IaC, such as Terraform, Helm is a plus\nA strong OOP mindset and a commitment to upholding SOLID principles\nA passion for writing clean, maintainable code, adhering to best practices (if you're a Clean Code/Coder/Architecture fan, you're more than welcome)\nKotlin experience is a huge plus, as this is our choice of language on the JDK\nAt least an intermediate level of English language skills since our team operates internationally\nWho are we?\nSupercharge is one of the fastest-growing tech companies globally, according to Financial Times (FT1000) and Deloitte (EMEA Fast500). Our in-house team of over 200 digital experts across our European and North American offices are passionately united in the pursuit of discovering and building better futures.\nWe cut through business, tech and regulatory complexity and fuse Behavior Science-based design and unique data & AI-focused technical competence to propel your business. We believe that innovation is a team effort: our strategists, designers, developers and engineers work shoulder to shoulder to enable what yesterday was still impossible.","description_format":"text","description_chars":3093,"description_truncated":false,"requirements":{"experience_years_min":3,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[{"language":"English","level":"Intermediate (B1)","optional":false}]},"benefits":[],"hiring_locations":[{"name":"Hungary","iso":"HU","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Digital Goods"],"lifecycle":[{"event":"open","at":"2026-10-20T18:03:57Z"}],"visa":[],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":4,"expected_fill_days":35,"reasons":["conf:2","velocity","win:early"],"computed_at":"2026-10-25T05:49:26Z"},"pay":null,"html_url":"https://alion.io/job/supercharge-senior-javakotlin-engineer-freelancer","json_url":"https://alion.io/job/supercharge-senior-javakotlin-engineer-freelancer.json","meta":{"generated_at":"2026-10-25T20:18:54Z","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":28778,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-26T00:00:00Z"}},"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":55006},"rest":"https://alion.io/mcp/rest/get_company?id=55006"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fsupercharge-senior-javakotlin-engineer-freelancer"},{"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%2Fsupercharge-senior-javakotlin-engineer-freelancer"},{"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%2Fsupercharge-senior-javakotlin-engineer-freelancer"},{"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/supercharge-senior-javakotlin-engineer-freelancer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fsupercharge-senior-javakotlin-engineer-freelancer"}]}