{"id":2908202,"url":"https://alion.io/job/thefrenchsourcer-senior-backend-software-engineer","title":"Senior Backend Software Engineer","company":{"id":4451662,"name":"The French Sourcer","domain":"thefrenchsourcer.com","url":"https://alion.io/company/thefrenchsourcer","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Manatal","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":null,"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":50000,"max_usd":85000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":173},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"CI/CD","optional":false},{"name":"Git","optional":false},{"name":"JavaScript","optional":false},{"name":"Node JS","optional":false},{"name":"TypeScript","optional":false}],"status":"live","first_seen_at":"2026-10-20T08:38:43Z","employer_posted_date":"2026-10-20","last_verified_at":"2026-10-24T21:37:28Z","board_verified":true,"closed_at":null,"days_open":4,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":4},"description":"Own the backbone of a platform processing tens of thousands of messages per second, with no room for downtime.\nSenior Backend Engineer - Real-Time Distributed Systems\nParis, France · Permanent · On-site\nWhat you'd actually work on\nDesigning and building highly available backend services for a real-time transactional platform\nDeveloping scalable microservices using server-side JavaScript and Node.js\nBuilding APIs and data models used across the wider platform\nDesigning event-driven workflows for authentication, flow control, routing, and asynchronous messaging\nImproving application performance, concurrency handling, and resource usage\nDesigning caching strategies while managing consistency and invalidation constraints\nOptimising relational database queries, indexes, transactions, and locking behaviour\nBuilding automated tests covering functional behaviour, integration, performance, and failure scenarios\nRunning load and stress tests based on real production traffic patterns\nDeploying containerised services through automated CI/CD pipelines\nImplementing monitoring, logging, tracing, and alerting for production services\nInvestigating incidents across application code, databases, messaging systems, and infrastructure\nEvolving critical services without interrupting a live platform used by hundreds of thousands of active users\nWhere it gets technically interesting\nTens of thousands of messages processed every second through a gateway responsible for authentication, routing, and asynchronous messaging\nEvent-driven architecture where retries, duplicate messages, ordering, and partial failures must be handled explicitly\nNode.js used for concurrent, high-throughput services beyond standard web applications\nRelational database performance under concurrent transactional workloads\nQuery optimisation, transaction boundaries, and lock management under contention\nCaching decisions that directly affect performance, consistency, and availability\nTraffic spikes that must be absorbed without degrading the user experience\nProduction changes requiring controlled rollout, monitoring, and rollback strategies\nStrict requirements around service availability and the protection of transactional and user data\nWhat we're looking for\n5+ years of experience building and operating backend services in production\nStrong experience with JavaScript or TypeScript and Node.js\nExperience designing microservices and event-driven systems\nGood understanding of distributed system failure modes\nExperience building services that handle high request or message volumes\nStrong knowledge of relational databases, data modelling, indexing, and query optimisation\nUnderstanding of transactions, locking, concurrency, and data consistency\nExperience designing and operating caching layers\nPractical knowledge of containers, CI/CD, and cloud infrastructure\nExperience with monitoring, logging, tracing, and production incident investigation\nAbility to evaluate performance, availability, and maintainability trade-offs\nExperience using Git, code reviews, and automated testing\nThe company\nA fast-growing digital entertainment and online gaming company operating across several European markets.\nThe company employs several hundred engineers and generates revenue in the hundreds of millions of euros. Its transactional platform supports high traffic volumes and a large active user base, making availability, performance, and data security central engineering concerns.\nHealth insurance, profit-sharing, and an employee incentive scheme.\nLanguages: Native or bilingual French and professional English.\nA search run by The French Sourcer, recruitment built for technical teams.","description_format":"text","description_chars":3669,"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":[{"language":"French","level":"Proficiency (C2)","optional":false},{"language":"English","level":"All levels","optional":false}]},"benefits":["Health insurance"],"hiring_locations":[{"name":"France","iso":"FR","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-10-20T08:38:43Z"}],"visa":[],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":3,"expected_fill_days":35,"reasons":["conf:0","velocity","win:early"],"computed_at":"2026-10-24T06:02:35Z"},"pay":null,"html_url":"https://alion.io/job/thefrenchsourcer-senior-backend-software-engineer","json_url":"https://alion.io/job/thefrenchsourcer-senior-backend-software-engineer.json","meta":{"generated_at":"2026-10-24T22:15:05Z","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":32580,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-25T00:00:00Z"}},"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":4451662},"rest":"https://alion.io/mcp/rest/get_company?id=4451662"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fthefrenchsourcer-senior-backend-software-engineer"},{"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%2Fthefrenchsourcer-senior-backend-software-engineer"},{"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%2Fthefrenchsourcer-senior-backend-software-engineer"},{"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/thefrenchsourcer-senior-backend-software-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fthefrenchsourcer-senior-backend-software-engineer"}]}