{"id":515469,"url":"https://alion.io/job/hexa-founding-ai-engineer-plato-backed-by-hexa","title":"Founding AI Engineer @Plato (backed by Hexa)","company":{"id":6140,"name":"HEXA","domain":"myhexa.com","url":"https://alion.io/company/hexa","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":true,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"A","score":92,"open_postings":24,"ghost_share":0,"stale_share":0.125,"repost_share":0,"time_to_fill_p50_days":77,"computed_at":"2026-11-05T05:54:30Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":"junior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Paris, France"],"countries":["FR"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":2,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agentic Workflows","optional":false},{"name":"AI Agents","optional":false},{"name":"LangChain","optional":false},{"name":"Mastra","optional":false},{"name":"TypeScript","optional":false},{"name":"AWS","optional":true},{"name":"AWS Bedrock","optional":true},{"name":"JavaScript","optional":true},{"name":"Node JS","optional":true},{"name":"PostgreSQL","optional":true},{"name":"React.js","optional":true},{"name":"Terraform","optional":true},{"name":"tRPC","optional":true}],"status":"closed","first_seen_at":"2026-09-07T10:42:02Z","employer_posted_date":"2026-09-07","last_verified_at":"2026-11-05T10:47:50Z","board_verified":false,"closed_at":"2026-11-05T10:47:50Z","days_open":59,"trust":{"level":"ok","repost_count":0,"flags":[],"days_open":58},"description":"Who are we\nPlato is building the AI OS for litigation lawyers.\nWith AI, the legal industry is on the verge of a major transformation. Litigation lawyers are overwhelmed by complex and repetitive tasks: complex damage calculations, thousands of documents to review, days spent drafting legal documents, and more.\nOur mission: Build the leading AI OS for litigation lawyers, enabling professionals to work 5x faster, by putting their whole firm on autopilot.\nPlato already supports more than 30 law firms and 1 major insurance company’s legal team, who use our solution daily to manage hundreds of active cases.\nFounded in January 2026 by Ben (CEO) and Alexandre (CTO), we are backed by Hexa (formerly eFounders), Europe’s leading startup studio. Hexa has launched over 35 companies, including unicorns such as Front, Aircall, and Spendesk, collectively generating more than €230M in ARR and raising over €750M in funding.\nPlato is live with real users, real data and real revenue, solving concrete legal workflows in production. We’re now looking for a Founding AI Engineer to help us turn the latest advances in AI into reliable products used every day by legal professionals.\nYour mission\nYou’ll work directly with Alexandre , our CTO, at the intersection of AI, software engineering and product.\nYour job is not to do AI research for the sake of research. You’ll experiment with models and approaches, understand what works, and turn the best solutions into reliable production systems.\nYou'll work on problems such as building agentic workflows, making sense complex legal documents, designing autonomous long-running agents, and improving the quality and reliability of AI-generated outputs.\nResponsibilities\nBuild AI-powered product features\nDesign and ship AI features used directly by lawyers\n\nBe at the bleeing edge of the agentic stack: memory, sandboxes, code mode, lots of tools, subagents…\n\nTurn prototypes and experiments into production-ready feature\n\nWork with complex data\nExtract, structure and reason over large volumes of unstructured legal documents\n\nBuild robust data and document-processing pipelines\n\nExperiment with different models and approaches to improve accuracy and reliability\n\nMake AI work in production\nEvaluate and improve agent outcomes through testing, evals and iteration\n\nOptimize systems for quality, latency and cost\n\nBuild the backend services and infrastructure needed to run AI reliably at scale\n\nShape the product\nWork directly with the founders and users to understand real-world problems\n\nMove quickly from problem → experiment → production (think days, not weeks)\n\nTake ownership of your projects from exploration to deployment\n\nThis role is for you if\nWe're looking for a strong software or AI engineer with 2+ years of experience who wants to build real-world AI products at the forefront of the agentic stack.\nYou like working close to founders and users, making pragmatic technical decisions, and shipping software that actually runs in production.\nYou’ll thrive in this role if you:\nHave a strong software engineering foundation, ideally with Typescript and experience shipping production systems\n\nHave experience with agents and/or evals and frameworks like Mastra, Eve, Pydantic, Langchain, etc…\n\nCan take an AI problem from experimentation to production\n\nEnjoy solving problems with no clear solution\n\nHave a strong product mindset and care about user impact\n\nAre autonomous and pragmatic, comfortable navigating early-stage ambiguity and shipping fast\n\nOur tech stack\nOur stack is designed to support AI-first workflows and production reliability.\nBackend & Frontend: TypeScript, Node.js, React, tRPC\n\nInfrastructure: AWS (Terraform)\n\nData & AI: Mastra, Bedrock\n\nDatabase: Postgres\n\nYou don't need to master every tool - what matters is your ability to design robust systems, learn fast, and make sound technical trade-offs.\nWhat we offer\nBuild alongside a strong AI expert: Work closely with Alexandre, our CTO, who has deep expertise in AI agents, and turn cutting-edge AI into production systems.\n\nOwnership & Impact: As the second engineering hire, you'll have real influence on the product and technical direction\n\nBring AI to real users: Build production AI systems that solve real problems in a complex, high-stakes domain\n\nHexa ecosystem: Access to expertise, resources, and network from one of Europe's leading startup studios\n\nCompetitive package: Attractive salary + meaningful equity\n\nParis-based team: Work alongside the founding team in our office\n\nGrowth: Opportunity to grow into a technical leadership role as the team scales\n\nPlato is committed to creating a diverse environment. All qualified applicants will receive consideration for employment irrespective of gender, origin, identity, background and sexual orientation.\nWe know there's a long way to go regarding diversity in our industry, which is why we encourage all applicants to apply to our open positions.","description_format":"text","description_chars":4940,"description_truncated":false,"requirements":{"experience_years_min":2,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Venture Capital","Angel Networks & Startup Accelerators"],"lifecycle":[{"event":"open","at":"2026-09-07T18:27:59Z"},{"event":"close","at":"2026-11-05T10:47:50Z"}],"visa":[],"liveness":null,"pay":null,"html_url":"https://alion.io/job/hexa-founding-ai-engineer-plato-backed-by-hexa","json_url":"https://alion.io/job/hexa-founding-ai-engineer-plato-backed-by-hexa.json","meta":{"generated_at":"2026-11-05T12:20:58Z","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":16029,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-06T00:00:00Z"}},"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":6140},"rest":"https://alion.io/mcp/rest/get_company?id=6140"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fhexa-founding-ai-engineer-plato-backed-by-hexa"},{"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%2Fhexa-founding-ai-engineer-plato-backed-by-hexa"},{"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%2Fhexa-founding-ai-engineer-plato-backed-by-hexa"},{"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/hexa-founding-ai-engineer-plato-backed-by-hexa\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fhexa-founding-ai-engineer-plato-backed-by-hexa"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":515469}},{"tool":"search_jobs","arguments":{"company":"myhexa.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":515469},"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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