{"id":2659289,"url":"https://alion.io/job/xephyr-senior-engineer-lessn","title":"Senior Engineer (Lessn)","company":{"id":4416970,"name":"Xephyr","domain":"xephyr.co","url":"https://alion.io/company/xephyr","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":null},"role":"Industrial Engineering","role_family":"Industrial Engineering","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":["Sydney, Australia"],"countries":["AU"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":75000,"max_usd":130000,"period":"year","method":"role_seniority_country_cell","sample_n":8},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AI Agents","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"C#","optional":false},{"name":"C++","optional":false},{"name":"CI/CD","optional":false},{"name":"GCP","optional":false},{"name":"Java","optional":false},{"name":"Python","optional":false},{"name":"Xero","optional":false}],"status":"live","first_seen_at":"2026-09-24T03:01:32Z","employer_posted_date":"2026-09-24","last_verified_at":"2026-10-16T16:53:48Z","board_verified":true,"closed_at":null,"days_open":22,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":22},"description":"About Lessn\nLessn lets a business pay any supplier invoice or recipient on a credit card, even suppliers who only accept bank transfers. The supplier receives a normal bank transfer the next business day, the fastest payout in the category, while our customers keep up to 55 days of working capital and earn rewards points on money that was already going out the door. Lessn reconciles automatically back into Xero and MYOB, with further accounting integrations on the roadmap.\nUnder the hood, Lessn is an orchestration engine sitting between the card networks, banks, the acquirer and the payout rails. We are now building the next layer: an agentic and deterministic AI/ML engine that decides the optimal way to pay every invoice, automatically, per business, using live and holistic open banking data. Nobody else in Australian B2B payments is building this, and it is a core part of what the next engineering hires are here to build.\nLessn is live and processing for 130+ active Australian businesses across professional services, construction, hospitality and retail, with tens of thousands of invoices paid and chargebacks running at roughly 0.02% of turnover, an exceptionally clean book for a B2B card business. We are AUSTRAC-enrolled with a full AML/CTF programme that has passed institutional review, and our direct American Express accreditation is well progressed.\nThe team you are joining\nLessn is a sub-15-person company led by David Grossman (Founder & CEO), a fourth-time founder, and Simon Daniels (COO & AML/CTF Compliance Officer). The board and investor base includes senior operators from Bain, PayPal ANZ, Afterpay, REA Group and Canaccord Genuity.\nThe Lessn platform was originally built by an outsourced development partner. In 2026, we brought the platform in-house and engaged a new engineering partner while building our permanent team. These two roles form that team. You will not inherit someone else’s standards; you will help set them. That is both the opportunity and the work.\nOur culture\nWe operate like a small, high-trust unit: everyone delivers, everyone has a voice in product and operations, and nobody hides behind process or hierarchy. You'll work in our office in Circular Quay, Monday, Wednesday and Thursday, and from home Tuesday and Friday.\nRole summary\nWe are hiring a Senior Software Engineer to join Lessn's embedded engineering team. You'll build production systems across our payments orchestration platform and contribute to the agentic AI/ML layer that decides the optimal way to pay every invoice. You'll also mentor our graduate engineer, holding the bar on code quality and supporting their growth.\nYour first twelve months\nMonths 1-3. Finish and stabilise the platform migration (supported by the previous outsourced partner), close out required compliance work, and take full ownership of deployment. Much of this is inherited work. It is not glamorous, but it is the foundation for everything after it.\nMonths 4-6. Automated tests run on every commit and block a bad merge. Deploys go through a pipeline, not by hand, and can be rolled back. A non-production environment can be rebuilt from code. Supplier verification and KYB automation are live. The graduate is shipping reviewed work without you unblocking them daily.\nMonths 7-12. The data foundation and the first working version of the decision engine. This is where the product becomes genuinely defensible, and you will have built it.\nThe practical detail\nProduction support. We run live payment rails. You are part of a shared escalation roster and are the technical escalation point for customer-impacting incidents. It is not a heavy on-call load, but it is real.\nRegulated environment. You will complete AML/CTF training on joining and annually and follow our data handling and change control obligations. Appointment is subject to a national police check.\nPerformance Reviewed at. 3 months, 6 months, then annually, against the outcomes set out above.\nResponsibilities\nSoftware engineering: Design, build and deploy production software across Lessn's payments orchestration platform, including integrations with card networks, banks, the acquirer and payout rails.\nData and AI engineering: Contribute to the design and delivery of the AI/ML decision engine that optimises how every invoice is paid (cheapest, most points, longest float, best use of cash, early-payment discount), using real-time open banking data. No prior AI/ML experience is required, we will teach you.\nAccounting integrations: Build and maintain reconciliation integrations with Xero, MYOB and future ERP platforms.\nEngineering process: Introduce and champion repeatable, scalable engineering practices, including CI/CD, automated testing and infrastructure-as-code.\nMentorship: Mentor our graduate engineer. Review their code, support their development, and hold the quality bar on what ships.\nQuality: You are a senior line of defence before work reaches production in a regulated fintech environment. If it is not right, it does not go.\nRoadmap input: Feed insights from delivery back into the product roadmap, across vertical integrations, accounting connectors, the Payday Super module, multi-currency payments and real-time reconciliation.\nWhat you bring\nRequired experience\n5+ years hands-on software engineering experience, including production systems in a commercial environment.\nStrong command of Python, and experience with at least one strongly typed language (C#, Java, C++ or similar).\nExperience with cloud infrastructure (AWS, Azure or GCP), infrastructure-as-code and containerisation.\nDemonstrated ability to design and ship software independently, with minimal oversight.\nComfortable operating in a small team with direct exposure to founders and rapid decision-making.\nPreferred experience\nExperience in fintech, payments or another regulated industry.\nExposure to AI/ML engineering and the data pipelines that feed it (not required, we will teach you).\nStartup or scaleup experience in a fast-paced technology business.\nExperience mentoring or leading junior engineers.\nYour traits\nSkills and tools can be learned. These cannot:\nCuriosity that drives you to build, experiment and learn without being asked.\nCommercial pragmatism that solves the customer's problem, not the most interesting one.\nJudgment that lets you pick an approach and move without perfect information.\nDirectness that speaks the truth without ego getting in the way.\nGenuine satisfaction from making someone else better, not just shipping your own code.","description_format":"text","description_chars":6540,"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":[],"hiring_locations":[{"name":"Australia","iso":"AU","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-10-16T00:08:49Z"}],"visa":[],"liveness":{"score":68,"band":"ok","label":"Likely open","p_open":1,"p_active":0.756,"p_room":0.9,"age_days":22,"expected_fill_days":38,"reasons":["conf:2","win:mid"],"computed_at":"2026-10-16T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/xephyr-senior-engineer-lessn","json_url":"https://alion.io/job/xephyr-senior-engineer-lessn.json","meta":{"generated_at":"2026-10-16T17:51:01Z","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":2617,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-17T00:00:00Z"}},"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":4416970},"rest":"https://alion.io/mcp/rest/get_company?id=4416970"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fxephyr-senior-engineer-lessn"},{"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%2Fxephyr-senior-engineer-lessn"},{"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%2Fxephyr-senior-engineer-lessn"},{"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/xephyr-senior-engineer-lessn\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fxephyr-senior-engineer-lessn"}]}