{"id":1854191,"url":"https://alion.io/job/transitionzero-lead-engineer-back-end","title":"Lead Engineer (Back-End)","company":{"id":1883291,"name":"Transitionzero","domain":"transitionzero.org","url":"https://alion.io/company/transitionzero","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Personio","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"lead","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":94000,"max_usd":189000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":41},"experience_years_min":7,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agile","optional":false},{"name":"CI/CD","optional":false},{"name":"Docker","optional":false},{"name":"FastAPI","optional":false},{"name":"Firestore","optional":false},{"name":"GCP","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Python","optional":false},{"name":"Redis","optional":false},{"name":"Scrum","optional":false},{"name":"GitOps","optional":true},{"name":"NumPy","optional":true},{"name":"Pandas","optional":true},{"name":"Terraform","optional":true},{"name":"Terragrunt","optional":true}],"status":"live","first_seen_at":"2026-05-19T15:42:42Z","employer_posted_date":"2026-05-19","last_verified_at":"2026-10-06T23:30:37Z","board_verified":true,"closed_at":null,"days_open":140,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":139},"description":"About the Role\nWe are looking for an experienced Lead Engineer (back-end) to lead the team building and scaling the infrastructure behind Scenario Builder, our electricity grid modelling platform. Scenario Builder is an in-browser platform that currently provides capacity expansion and dispatch modelling through an accessible no-code interface. The vision for Scenario Builder is to expand into power flow modelling to create a fully integrated grid modelling platform with the features and functionality needed to enable users to develop bankable scenarios that support energy investment decisions.\nYou will line-manage a small team of engineers while remaining a highly active individual contributor. You will own the technical shape of engineering work on the back-end team - leading planning, architecture, and code quality. You will work closely with the wider product and engineering team to design, develop, and maintain the back-end services that power our platform.\nThis hybrid role is based out of our London office near Waterloo Station and reports to the Head of Platform.\nResponsibilities\nBack-end development & architecture\nDesign, develop, and maintain scalable back-end services and APIs using Python and modern frameworks (FastAPI).\n\nDesign and build high-performance API endpoints to handle complex hierarchical data queries and multi-dimensional aggregations for grid modelling computations\n\nEnsure system reliability, performance, and security through best practices in code quality, testing, and monitoring.\n\nCollaborate with front-end engineers to design and implement RESTful APIs that support our web application.\n\nCollaborate with data engineers and domain experts on the evolving core data model\n\nInfrastructure & DevOps\nManage and optimise cloud infrastructure (GCP) to support our computational workloads.\n\nImplement and maintain CI/CD pipelines to enable rapid, reliable deployments.\n\nMonitor system health and performance, proactively identifying and resolving issues.\n\nImplement and maintain infrastructure-as-code\n\nTechnical leadership & collaboration\nParticipate and lead in code reviews, architectural discussions, and technical planning sessions.\n\nOwn technical planning: break down roadmap items into well-scoped engineering work, lead estimation, and drive architectural decision records (ADRs).\n\nCollaborate with cross-functional teams, including product, data engineering, and modelling, to deliver impactful features.\n\nSet and uphold the team's technical standards - code quality, testing strategy, API design - through direct example and code review.\n\nPeople & line management\nLine-manage a team of 3-5 engineers: run regular 1:1s, support career development, and provide timely, constructive feedback.\n\nPartner with the Head of Platform on performance reviews and personal development plans.\n\nAct as the first point of escalation for day-to-day technical blockers\n\nAbout You\nYou should have a long-term commitment to advancing the energy transition and be driven to build robust, scalable systems that power our grid modelling platform. Passionate about creating highly performant back-end services, you understand the technical challenges associated with building niche B2B products that handle complex computational workloads. In addition to seeking out people with a proactive, problem-solving attitude and an eye for detail, as a growing organisation, collegiality and empathy for our coworkers are a requisite. While we are a rapidly growing tech startup, we are also a non-profit, so a high level of adaptability and willingness to approach challenges with creativity and curiosity is essential.Skills & Experience\nEssential\n7+ years of experience in back-end software development, with strong proficiency in Python.\n\nExperience designing and building RESTful APIs and microservices architectures.\n\nStrong understanding of database technologies (PostgreSQL, Redis, Firestore), ORMs and data modelling principles.\n\nExperience with cloud platforms (preferably GCP) and containerisation technologies (Docker).\n\nSolid understanding of software engineering best practices, including testing, code review, and documentation.\n\nExcellent problem-solving skills and ability to work independently on complex technical challenges.\n\nExperience line managing or formally mentoring engineers, with confidence running 1:1s and supporting career development.\n\nUnderstanding of OAuth and web security best practices.\n\nExperience with AGILE/Scrum based ways-of-working\n\nDesirable\nExperience in the energy sector or with computational modelling/simulation software.\n\nFamiliarity with scientific computing libraries (NumPy, Pandas) and optimisation frameworks.\n\nExperience with generative AI/LLMs in applied engineering contexts\n\nExperience with infrastructure-as-code tools (Terraform, Terragrunt) and GitOps practices.","description_format":"text","description_chars":4850,"description_truncated":false,"requirements":{"experience_years_min":7,"management_years_min":null,"team_size_min":3,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-10-04T20:18:58Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Skilled Worker","cap_exempt":false,"checked_at":"2026-10-06T06:21:00+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":8,"band":"cold","label":"Long shot","p_open":1,"p_active":0.275,"p_room":0.28,"age_days":139,"expected_fill_days":24,"reasons":["conf:14","win:tail","crowd:"],"computed_at":"2026-10-06T05:45:30Z"},"pay":null,"html_url":"https://alion.io/job/transitionzero-lead-engineer-back-end","json_url":"https://alion.io/job/transitionzero-lead-engineer-back-end.json","meta":{"generated_at":"2026-10-07T01:59:05Z","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","counted_by":"address","units_charged":1,"used_today":3209,"day_limit":5000,"remaining_today":1791,"minute_limit":60,"resets_at":"2026-10-08T00:00:00Z"}},"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":1883291},"rest":"https://alion.io/mcp/rest/get_company?id=1883291"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Ftransitionzero-lead-engineer-back-end"},{"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%2Ftransitionzero-lead-engineer-back-end"},{"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%2Ftransitionzero-lead-engineer-back-end"},{"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/transitionzero-lead-engineer-back-end\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Ftransitionzero-lead-engineer-back-end"}]}