{"id":2487286,"url":"https://alion.io/job/system1-group-backend-software-engineer-system1-group","title":"Backend Software Engineer - System1 Group","company":{"id":172464,"name":"System1 Group","domain":"system1group.com","url":"https://alion.io/company/system1-group","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"JazzHR","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"middle","employment_type":null,"work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"posting_text","remote_working_hours":null,"hiring_geo_confidence":"explicit","locations":[],"countries":[],"hiring_countries":["GB"],"hiring_countries_total":1,"salary":null,"salary_estimate":{"min_usd":63000,"max_usd":185000,"period":"year","method":"global_role_seniority_cell","sample_n":2517},"experience_years_min":3,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AI Agents","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"Claude Code","optional":false},{"name":"GCP","optional":false},{"name":"Machine Learning","optional":false},{"name":"Model Context Protocol","optional":false},{"name":"Python","optional":false},{"name":"Rest API","optional":false}],"status":"live","first_seen_at":"2026-10-14T00:54:58Z","employer_posted_date":"2026-10-14","last_verified_at":"2026-10-14T06:48:38Z","board_verified":true,"closed_at":null,"days_open":0,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":0},"description":"Backend Software Engineer\nLocation: UK, remote with occasional travel\n\nIn the words of one of our senior clients recently…\n“Market Research has changed more in the past 3 years, than in the previous 40”\nAbout System1.\nSystem1 is The Creative Effectiveness Platform. Our target customers are the world’s largest advertisers. We predict and improve marketing effectiveness. Our advertising and idea tests measure emotion to give our customers the most accurate predictions of the business impact of creativity.\nTo learn more about us, please visit System1 Group | Create with Confidence\nAbout The Role\nWe are looking for a talented and ambitious Backend Software Engineer to join the empowered product team building System1’s next-generation AI platform. You will help shape how the world’s largest brands predict and improve the effectiveness of their advertising, building the Python services, APIs and integrations that power the platform. You will work as a first-class member of the product team alongside your Product Manager, Product Designer and Team Lead to discover and deliver outcomes that matter to our customers and our business. This is a rare opportunity to help build a new platform from the ground up, engineer in a genuinely AI-native way, and work at the speed our market demands.\nAre you energised by being a true partner in the product team, helping decide what to build, not just how to build it?\n\nDo you already engineer through Claude Code every day, with your own skills and subagents, and the discipline to own every line you ship?\n\nAre you motivated by outcomes over outputs, and by getting production systems working at scale rather than shipping features for their own sake?\n\nDo you want to join us to excite and change the industry?\nWhat will you be doing?\nPartner as a member of an empowered product team (Product Manager, Product Designer, Team Lead and engineers), sharing accountability for the outcomes your team commits to.\n\nContribute to continuous product discovery, helping the team assess feasibility early and building quick technical prototypes to test ideas before we commit to building.\n\nDesign, build and own Python backend services for our AI platform, from media upload through asynchronous ML processing to insight delivery.\n\nWork API-first and spec-driven, defining clean REST contracts that serve headless frontends, internal teams and customer integrations.\n\nBuild MCP servers that make System1’s data and capabilities available to AI agents and tools, for customers and colleagues alike.\n\nEngineer through Claude Code day to day, building and sharing skills, subagents and workflows that raise the speed and quality of the whole team.\n\nTake code into production at scale with confidence, bringing the testing, observability and reliability our enterprise customers expect.\n\nContribute to our infrastructure as code and cloud environment, understanding how your services are deployed, run and scaled.\n\nWork alongside our data scientists to bring models into production, learning the machine learning side of the platform as you go.\n\nBuild with enterprise security and compliance in mind, so the world’s largest advertisers can trust the platform with their data.\n\nYou need to be this kind of person:\nA missionary, not a mercenary. You care deeply about the customer problem and the outcome, not just the code.\n\nOutcome-driven. You measure your success by the change you create for customers and the business, not by tickets closed.\n\nAn engineer first, with AI as a force multiplier. You use AI tools to move faster with rigour, not to skip the thinking.\n\nComfortable with ambiguity and ownership. You don’t wait for a perfectly specified ticket, you frame the problem with your team and go.\n\nA clear communicator, able to explain technical trade-offs to product, design, data science and commercial colleagues as well as to fellow engineers.\n\nCurious and a lifelong learner, with the integrity to back your point of view with evidence in front of colleagues, customers and stakeholders.\n\nAble to see the bigger picture without losing attention to detail, your code quality is as strong as your product thinking.\n\nA natural collaborator, comfortable working with all departments at all seniorities, and equally able to drive work forward independently.\n\nPassionate about (good!) advertising, how it works and how it can be improved or excited to become so.\n\nYou need to have the following experience:\nTo be successful in this role, you will have approximately 3-5 years of real-world software engineering experience and be ready to operate as a first-class member of an empowered product team, where you’ll have outsized influence on the outcomes we deliver.\nStrong commercial experience building backend services in Python.\n\nExperience designing and building REST APIs, ideally spec-driven, with a clear understanding of what frontends need from a headless architecture.\n\nExperience building SaaS software and taking code into production at scale, whether as part of a team or with personal responsibility for it.\n\nHands-on experience with at least one major cloud platform (e.g. AWS, Azure, GCP).\n\nA working understanding of infrastructure as code and the ability to contribute to it.\n\nSolid experience working with databases and data modelling.\n\nDaily use of Claude Code as an engineering tool, including building your own skills and subagents, with an engineering-led approach rather than vibe coding.\n\nExperience building MCP servers, or a strong understanding of MCP and a drive to build with it.\n\nExperience working in a product operating model, as part of an empowered, cross-functional product team.\n\nFamiliarity with the security and compliance requirements of enterprise customers.\n\nFamiliarity with machine learning systems, or a genuine desire to learn, is a plus.\n\nThis role will require you to operate across multiple discovery and delivery threads in parallel, balancing speed with the rigour and reliability our customers expect.\nBenefits\nWe offer a competitive salary and bonus scheme, including health insurance, and pension. Our people are important to us, and we understand that each person has a life outside of work and we therefore offer flexible, remote working within the UK, with occasional travel to get together for company and team meet-ups. We also offer several wellbeing resources such as “de-clutter” afternoons for your personal and professional needs.\nWe encourage learning and offer education reimbursement opportunities.\nWe have recognition schemes, and regular socials, including summer and winter parties!\nWe welcome applicants from all diverse communities and encourage our candidates to ask us about reasonable adjustments that we may be able to make to support through our recruitment process and while in post.","description_format":"text","description_chars":6803,"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":[]},"benefits":["Health insurance"],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Market Research","Media & Audience Measurement"],"lifecycle":[{"event":"open","at":"2026-10-14T00:54:58Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Senior or Specialist Worker, Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Global Business Mobility: Senior or Specialist Worker; Skilled Worker","cap_exempt":false,"checked_at":"2026-10-14T06:20:30+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":86,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.86,"p_room":1,"age_days":0,"expected_fill_days":44,"reasons":["conf:5","win:early"],"computed_at":"2026-10-14T06:34:16Z"},"pay":null,"html_url":"https://alion.io/job/system1-group-backend-software-engineer-system1-group","json_url":"https://alion.io/job/system1-group-backend-software-engineer-system1-group.json","meta":{"generated_at":"2026-10-14T09:03:45Z","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":9967,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-15T00:00:00Z"}},"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":172464},"rest":"https://alion.io/mcp/rest/get_company?id=172464"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fsystem1-group-backend-software-engineer-system1-group"},{"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%2Fsystem1-group-backend-software-engineer-system1-group"},{"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%2Fsystem1-group-backend-software-engineer-system1-group"},{"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/system1-group-backend-software-engineer-system1-group\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fsystem1-group-backend-software-engineer-system1-group"}]}