{"id":49894,"url":"https://alion.io/job/cryptonext-security-senior-fullstack-engineer-typescript","title":"Senior Fullstack Engineer (TypeScript)","company":{"id":6520,"name":"CryptoNext Security","domain":"cryptonext-security.com","url":"https://alion.io/company/cryptonext-security","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workable","truth_index":null},"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":["Paris, France"],"countries":["FR"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":51000,"max_usd":86000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":163},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agentic Workflows","optional":false},{"name":"Node JS","optional":false},{"name":"PostgreSQL","optional":false},{"name":"React.js","optional":false},{"name":"Rest API","optional":false},{"name":"shadcn/ui","optional":false},{"name":"Tailwind CSS","optional":false},{"name":"TypeScript","optional":false},{"name":"Vite","optional":false},{"name":"Go","optional":true},{"name":"JavaScript","optional":true},{"name":"Radix UI","optional":true}],"status":"live","first_seen_at":"2026-08-10T00:00:00Z","employer_posted_date":"2026-08-10","last_verified_at":"2026-10-18T04:26:49Z","board_verified":true,"closed_at":null,"days_open":69,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":69},"description":"Who we are\nCryptoNext Security is a deeptech startup specializing in post-quantum cryptography. Our solutions help businesses and institutions prepare for a future where quantum computers will challenge traditional data security. We work with leading clients in finance, defense, and telecommunications.\nOn a daily basis, you will\nOwn features end to end in TypeScript: Hono and Node.js on PostgreSQL, React SPA on the front.\nDesign HTTP APIs consumed through Hono's typed RPC client, with generated OpenAPI specs.\nModel and query PostgreSQL: schema, migrations, query performance.\nBuild interfaces with Vite, TanStack, Tailwind and shadcn/ui.\nWork directly with Product and QA.\nWrite the unit and integration tests that back your features, and give QA what they need to automate the rest.\nReview code.\nUse AI coding tools as leverage under your own judgement, staying accountable for what lands in the repo.\nPropose upgrades and refactorings, and explain the trade-offs you accepted.\nHow we work\nA team of six engineers, within our 15-person R&D department. A single TypeScript monorepo, with shared types and tooling across services and front. Three days a week in our Paris office, the rest remote. Short feedback loops, high standards. We ship a working version early rather than polishing in isolation, and keep solutions as simple as the problem allows. Our products ship on-premise, sometimes into air-gapped environments, so builds have to be reproducible and dependencies deliberate. We build software our clients rely on for security: secure defaults, reviewed dependencies and tested code are part of shipping, not a later phase. We care more about a decision you can justify than a pattern you can name.\nRequirements\nThe skills you'll need\nStrong TypeScript across the stack: strict mode, generics, types shared between server and client instead of duplicated.\nNode.js backend: API design, auth, error handling, observability.\nAsynchronous processing: queue consumers and background workers, idempotency, retries and failure handling, backpressure.\nPostgreSQL: schema design, migrations and rollbacks, indexing, reading a query plan.\nStrong React: hooks, composition, clear state boundaries, client-side routing and server state caching.\nComfortable with a modern frontend toolchain: fast bundling, utility-first styling, component libraries you extend rather than fight.\nAPI contract design: REST, OpenAPI, typed clients, versioning.\nUnit and integration testing, with a defensible position on what belongs at which level and on what is worth testing at all.\nReal use of AI-assisted development in a production codebase: agentic workflows, context management, reviewing generated output as critically as a colleague's merge request. You have a view on where these tools pay off and where they create debt.\nSeniority means you can say why you chose an approach, what you rejected, and what it will cost in six months.\nBonus skills\nGo, used in parts of our codebase.\nHono typed RPC and end-to-end type inference.\nSecure coding practices and application security.\nBasic understanding of cryptography and cybersecurity.\nExperience in a startup or deeptech environment.\nBenefits\nThe team you'll be joining\nYou will join a team of six engineers who own their features across the whole stack, inside our 15-person R&D department, working closely with Product and QA. You will report to the Head of Engineering and collaborate with other departments to build the backend services and interfaces our clients depend on.\nOur recruitment process\n1. Initial discussion with our HR team to explore your background and motivations.\n2. Technical interview with a developer: a live coding session of 1 to 1.5 hours. AI coding tools are required, not merely allowed. We are interested in how you direct and review them. No take-home assignment.\n3. Meeting with a manager to ensure alignment with our company culture.\n4. If successful, you'll receive a final offer!\nWhat's in it for you at CryptoNext\nA stimulating work environment with cutting-edge technological challenges.\nA competitive salary, aligned with our compensation philosophy.\nA deep dive into the exciting world of post-quantum cryptography and cybersecurity.\nReady to join the adventure? Apply now!","description_format":"text","description_chars":4257,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"master","optional":false},"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Cybersecurity"],"lifecycle":[{"event":"open","at":"2026-08-10T00:00:00Z"}],"visa":[],"liveness":{"score":13,"band":"cold","label":"Long shot","p_open":1,"p_active":0.45,"p_room":0.28,"age_days":68,"expected_fill_days":26,"reasons":["conf:5","win:tail","crowd:"],"computed_at":"2026-10-17T05:46:00Z"},"pay":null,"html_url":"https://alion.io/job/cryptonext-security-senior-fullstack-engineer-typescript","json_url":"https://alion.io/job/cryptonext-security-senior-fullstack-engineer-typescript.json","meta":{"generated_at":"2026-10-18T07:18:34Z","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":10939,"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":6520},"rest":"https://alion.io/mcp/rest/get_company?id=6520"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcryptonext-security-senior-fullstack-engineer-typescript"},{"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%2Fcryptonext-security-senior-fullstack-engineer-typescript"},{"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%2Fcryptonext-security-senior-fullstack-engineer-typescript"},{"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/cryptonext-security-senior-fullstack-engineer-typescript\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcryptonext-security-senior-fullstack-engineer-typescript"}]}