{"id":3817181,"url":"https://alion.io/job/gflenv-senior-software-engineer","title":"Senior Software Engineer","company":{"id":1802390,"name":"GFL Environmental","domain":"gflenv.com","url":"https://alion.io/company/gflenv","size_band":"5000+","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"B","score":75,"open_postings":17,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-11-07T05:47:08Z"}},"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":["Vaughan, Canada"],"countries":["CA"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":6,"visa_sponsorship":true,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Amazon Aurora","optional":false},{"name":"Amazon ECS","optional":false},{"name":"Amazon EKS","optional":false},{"name":"Amazon S3","optional":false},{"name":"ASP.NET Core","optional":false},{"name":"AWS","optional":false},{"name":"AWS Fargate","optional":false},{"name":"AWS Lambda","optional":false},{"name":"C#","optional":false},{"name":"CI/CD","optional":false},{"name":"Clean Architecture","optional":false},{"name":"CloudFormation","optional":false},{"name":"Dependency Injection","optional":false},{"name":"GitHub Actions","optional":false},{"name":"JavaScript","optional":false},{"name":"Material UI","optional":false},{"name":"MS SQL","optional":false},{"name":"React.js","optional":false},{"name":"Redux Toolkit","optional":false},{"name":"Rest API","optional":false},{"name":"SQL","optional":false},{"name":"State Management","optional":false},{"name":"Tailwind CSS","optional":false},{"name":"Terraform","optional":false},{"name":"TypeScript","optional":false},{"name":"Vite","optional":false},{"name":"Webpack","optional":false},{"name":"Docker","optional":true},{"name":"Kubernetes","optional":true},{"name":"Redux","optional":true}],"status":"live","first_seen_at":"2026-06-09T00:00:00Z","employer_posted_date":"2026-06-09","last_verified_at":"2026-11-07T16:49:29Z","board_verified":true,"closed_at":null,"days_open":151,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":151},"description":"Role Overview\nWe are seeking a highly skilled Senior Full-Stack Developer with 6+ years of experience to lead the digital transformation of our core enterprise applications. You will be responsible for the end-to-end modernization of legacy .NET Framework 4.8 MVCmonoliths into high-performance, .NET 6+ and upmicroservices and APIs, paired with a modern Reactfrontend and hosted on AWS.\nThis is not a \"maintenance\" role; it is a \"re-engineering\" role. You will bridge the gap between reliable legacy logic and the future-proof scalability of modern cloud architecture.\nKey Responsibilities\nLegacy Deconstruction:Analyze existing .NET 4.8 MVC applications to identify business logic, dependencies, and integration points for migration.\n\nArchitecture Migration:Lead the transition from monolithic architectures to modern design patterns (Microservices, Hexagonal, or Clean Architecture).\n\nBackend Modernization:Rewrite and refactor legacy C# code to .NET 6/8+, implementing cross-platform compatibility and improved performance.\n\nFrontend Revolution:Replace Razor/Server-side rendering with a decoupled, state-of-the-art React SPA (Single Page Application) using TypeScript and modern state management (Redux Toolkit, TanStack Query).\n\nCloud Orchestration:Design and deploy the modernized stack on AWS, leveraging services like Lambda, ECS (Fargate), S3, and RDS.\n\nAPI Design:Build robust, secure RESTful APIs that serve as the bridge between the new React frontend and the modernized backend.\n\nCI/CD Implementation:Establish automated pipelines for building, testing, and deploying both the .NET and React components.\n\nTechnical Requirements\nBackend Expertise\nLegacy:Deep understanding of .NET Framework 4.8, ASP.NET MVC, and Web API.\n\nModern:Expert-level proficiency in .NET 6/7/8and ASP.NET Core.\n\nLanguage:Advanced C# skills (Generics, LINQ, Async/Await, Dependency Injection).\n\nDatabase:Experience with SQL Server (T-SQL) and migrating to AWS-managed databases (RDS/Aurora).\n\nFrontend Expertise\nReact:Strong experience with Functional Components, Hooks, and modern React patterns.\n\nLanguages:JavaScript (ES6+) and TypeScript(Required).\n\nTools:Experience with Vite or Webpack, and CSS frameworks (Tailwind, Material UI).\n\nCloud & DevOps (AWS)\nCompute:Hands-on experience with AWS Lambda(Serverless) or Amazon ECS/EKS.\n\nInfrastructure:Familiarity with Infrastructure as Code (CloudFormation, CDK, or Terraform).\n\nDeployment:Building CI/CD pipelines (GitHub Actions).\n\nPreferred Qualifications\nExperience using the AWS Porting Assistant for .NETor AWS Transform.\n\nFamiliarity with containerization (Docker) and orchestration.\n\nKnowledge of Authentication/Authorization standards (OAuth2, OpenID Connect, AWS Cognito).\n\nProven track record of successfully migrating at least one large-scale enterprise application.\n\nWe thank you for your interest. Only those selected for an interview will be contacted.\nGFL is committed to equal opportunity for all, without regard to race, religion, color, national origin, citizenship, sex, sexual orientation, gender identity, age, veteran status, disability, genetic information, or any other protected characteristic. If you are interested in applying for employment and need special assistance or an accommodation to apply for a posted position, please contact  \nPlease note that GFL does not provide visa sponsorship for this position. Valid work authorization in the country where the job is located is required. Successful candidates will be required to provide valid documentation confirming their eligibility to work in the country where the job is located prior to their start date.\nThis hiring process may utilize machine-based systems to assist in screening and assessing applicants. Final selection decisions are made by our recruitment team.","description_format":"text","description_chars":3822,"description_truncated":false,"requirements":{"experience_years_min":6,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Waste Management"],"lifecycle":[{"event":"open","at":"2026-11-05T16:30:15Z"}],"visa":[],"liveness":{"score":7,"band":"cold","label":"Long shot","p_open":1,"p_active":0.256,"p_room":0.28,"age_days":151,"expected_fill_days":28,"reasons":["conf:0","stale_co","velocity","win:tail","crowd:brand"],"computed_at":"2026-11-07T05:47:08Z"},"pay":null,"html_url":"https://alion.io/job/gflenv-senior-software-engineer","json_url":"https://alion.io/job/gflenv-senior-software-engineer.json","meta":{"generated_at":"2026-11-07T17:06:07Z","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":24697,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-08T00:00:00Z"}},"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":1802390},"rest":"https://alion.io/mcp/rest/get_company?id=1802390"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fgflenv-senior-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%2Fgflenv-senior-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%2Fgflenv-senior-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/gflenv-senior-software-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fgflenv-senior-software-engineer"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3817181}},{"tool":"search_jobs","arguments":{"company":"gflenv.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3817181},"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. Docs: https://alion.io/developers"}}