Jason is available for hire
Hire JasonJason Brown
Verified Expert in Engineering
Mobile Developer
Bagworth, United Kingdom
Toptal member since November 15, 2016
Bio
Jason is a software architect with 38 years of experience, including PCI DSS compliance for card payments in UK rail ticketing at Atos Worldline. He founded Schedrix, a Microsoft Dynamics 365 Business Central extension that sequences production for food and drink factories using a Google OR-Tools solver on Azure, and led its AppSource submission. Jason designs the architecture and leads an AI-assisted delivery pipeline that is held to strict testing and CI gates.
Portfolio
Capability Systems
Dynamics 365 Business Central, AL, Microsoft AppSource, Python, FastAPI...
CineMe Ltd
JavaScript, React, Node.js, Next.js, TypeScript, Vercel, AI Integration...
Seer Software LLC
.NET MAUI, Xamarin.Forms, C#, Firebase Cloud Messaging (FCM), GitHub Actions...
Experience
- Microsoft SQL Server - 20 years
- C# - 18 years
- Software Architecture - 10 years
- TypeScript - 5 years
- Azure - 3 years
- AI-assisted Development - 2 years
- AL - 1 year
- Dynamics 365 Business Central - 1 year
Work Experience
Founder and Principal Architect
2026 - PRESENT
Capability Systems
- Designed and led Schedrix, a Business Central extension that proposes the order to run production orders on each line in food and drink factories.
- Architected an AL extension calling a Python FastAPI service on Azure that solves line sequences with a constraint solver.
- Built plain-English changeover rules: Claude interprets each rule, the planner confirms it, and allergen cleans can't be shortened by other rules.
- Took the extension through AppSource: own object range, AppSourceCop with warnings as errors, code signing, passed validation, submitted October 2026.
- Added breakdown replanning: a planner describes the breakdown in a sentence, and Schedrix records the downtime and replans the remaining window.
- Set up an AI-assisted delivery pipeline: I wrote the specs and architecture, agents wrote most of the code, and independent review gated 140+ merged PRs.
- Built a local CI gate running about 600 AL tests in a Business Central container, 800+ Python tests, and 500+ web tests on every change.
- Provisioned the Azure platform with Terraform: Container Apps, PostgreSQL, Key Vault, and Application Insights telemetry from every BC tenant.
Technologies: Dynamics 365 Business Central, AL, Microsoft AppSource, Python, FastAPI, Google OR-Tools, Constraint Programming, Azure, Terraform, Claude API, Next.js, TypeScript, PostgreSQL, Solution Architecture, Agentic AI Systems, Large Language Model Operations (LLMOps), Orchestration, Back-end Development, AI Agents, Agentic Coding, Claude, Sentry, Artificial Intelligence (AI), Front-end Development, Software Development, Software Development Lifecycle (SDLC), Prompt Engineering, AI Tools
Full-stack Developer
2026 - 2026
CineMe Ltd
- Led the beta-to-production launch of Cineme.ai, an AI film-production SaaS, delivering a live demo-ready for the 2026 Cannes Film Festival on a fixed, immovable deadline.
- Worked directly with a BAFTA-nominated director-founder and a technical advisor from Google DeepMind to meet production standards under tight time pressure.
- Transitioned an AI-generated/AI-assisted codebase to a stable, production-grade deployment on Next.js 15, Vercel, Supabase, and TypeScript.
- Implemented Inngest to orchestrate reliable, event-driven background workflows and long-running AI jobs in a live production environment.
- Optimized server-side rendering and serverless functions, hardening performance and reliability for a high-visibility live showcase.
- Restructured the database and cloud model for production scale and stabilized Anthropic and OpenAI API integrations powering the platform's AI processes.
- Maintained strong daily overlap with the London time zone throughout the engagement to collaborate closely with the founder and advisor.
Technologies: JavaScript, React, Node.js, Next.js, TypeScript, Vercel, AI Integration, Claude Code, Inngest, Serverless Functions, Anthropic, OpenAI API, Image Generation, GitHub Actions, Agentic Coding, AI-assisted Development, Software Engineering, Architecture, Software Architecture, Security, Solution Architecture, AI Systems, Back-end Development, Sentry, Artificial Intelligence (AI), Front-end Development, Software Development, Software Development Lifecycle (SDLC), Prompt Engineering, AI Tools
Senior .NET MAUI Developer
2025 - 2026
Seer Software LLC
- Migrated a large Xamarin.Forms childcare-management app to .NET MAUI on iOS and Android, keeping the existing features working throughout.
- Rebuilt the app's custom controls for .NET MAUI, replacing Xamarin-only renderers with MAUI handlers.
- Integrated Firebase Cloud Messaging for push notifications to parents and staff on both platforms.
- Built a GitHub Actions pipeline that builds, signs, and releases the app to the Apple App Store and Google Play.
- Rejoined in August 2026 to tighten up releases, giving both apps one build number and a pipeline that only ships builds from main.
- Added Sentry release health and fixed two long-standing Android crashes during the August 2026 return.
Technologies: .NET MAUI, Xamarin.Forms, C#, Firebase Cloud Messaging (FCM), GitHub Actions, iOS, Android, Mobile App Development, Sentry, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Senior Full-stack Developer
2025 - 2025
BlueFleet S.L.
- Developed a Flutter app for data input, which included GPS location and details of deliveries and collections.
- Built a .NET Core 8/C# server with data stored via Entity Framework Core on a PostgreSQL database.
- Deployed the system via Fastlane to Google Play Console, Docker Hub, and a Docker Compose/YAML script to Linux servers.
Technologies: Flutter, C#, Angular, HTML, Application State Management, Firebase, SQL, PostgreSQL, Kubernetes, Mobile App Design, Minimum Viable Product (MVP), APIs, Identity & Access Management (IAM), Back-end, Mobile Development, Model View ViewModel (MVVM), Web Development, Microservices, React, Mobile App Testing, Unit Testing, Supabase, ASP.NET Core, Server-side Rendering (SSR), Test-driven Development (TDD), Web Content Accessibility Guidelines (WCAG), Web Performance Optimization (WPO), .NET 10, Full-stack Development, Linux, Git, AI Integration, API Integration, GPS, Cross-platform App Development, Software Engineering, Architecture, Software Architecture, iPhone, SQL Server 2017, Dependency Injection, Solution Architecture, API Design, Back-end Development, Sentry, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Senior C#/C++ Developer
2024 - 2025
Connells Group
- Designed and developed a C++ and C# interface to a SOAP service for requesting and tracking home conveyancing requests.
- Created Azure functions and queues to securely and reliably receive webhook requests.
- Configured deployments using Azure DevOps pipelines and Octopus Deploy.
Technologies: C#, C++, SQL Server 2019, CI/CD Pipelines, SQL, Azure DevOps, Octopus Deploy, React, Azure, APIs, Back-end, Web Development, Unit Testing, Cloud Architecture, ASP.NET Core, Test-driven Development (TDD), xUnit, xUnit.net, .NET 10, Full-stack Development, Git, API Integration, Azure Cloud Services, Microsoft Azure, Azure App Service, GitHub Actions, Software Engineering, Architecture, Software Architecture, API Design, Back-end Development, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Senior Full-stack Developer
2023 - 2024
Flying Colours
- Designed and developed the Flutter app responsible for recording flight training outcomes and uploading these to the back-end server when next connected to the Internet.
- Spearheaded the creation of an Angular back-end management system.
- Containerized the software components to enable deployment via a Docker Compose/YAML script.
Technologies: Angular, C#.NET, Flutter, Docker, SQL Server 2019, Full-stack, HTML, CSS, JavaScript, TypeScript, Mobile Apps, .NET Core, Mobile, Redux, .NET, Entity Framework, Entity Framework Core, REST APIs, Cloud Services, ASP.NET, C#, Microsoft Visual Studio, SQLite, Microsoft SQL Server, Android, Visual Studio 2022, Visual Studio Code (VS Code), Web Services, Front-end, Dart, Mobile App Development, Application State Management, Riverpod, SQL, Stripe API, Mobile App Design, Minimum Viable Product (MVP), APIs, Content Management Systems (CMS), Identity & Access Management (IAM), Back-end, Mobile Development, Model View ViewModel (MVVM), Web Development, Microservices, Python, Mobile App Testing, Unit Testing, Stripe, ASP.NET Core, Server-side Rendering (SSR), Test-driven Development (TDD), Web Content Accessibility Guidelines (WCAG), Web Performance Optimization (WPO), RxJS, WCAG 2, xUnit, xUnit.net, .NET 10, Full-stack Development, Linux, Git, API Integration, GPS, Cross-platform App Development, Software Engineering, Architecture, Software Architecture, iPhone, Dependency Injection, API Design, Back-end Development, Sentry, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Senior Full-stack Developer
2018 - 2023
Capability Systems
- Developed and designed a mobile app, Angular website, and C# server back end that collected and stored health-related information in an SQL server database.
- Designed the system to help with the training and advancement of children with learning difficulties. Ensured the system met the US Health HIPAA Privacy Rule.
- Spearheaded the design and development of the Angular website, including the NgRx Redux-style state management of the website.
Technologies: Angular, Xamarin, C#.NET, SQL Server 2016, Flutter, Full-stack, HTML, CSS, JavaScript, TypeScript, Mobile Apps, Mobile GPS, .NET Core, Mobile, Redux, .NET, Entity Framework, Entity Framework Core, Web Services, REST APIs, ASP.NET, C#, Microsoft Visual Studio, SQLite, Microsoft SQL Server, Android, Visual Studio 2022, Visual Studio Code (VS Code), Cloud Services, Front-end, Dart, SQL, Mobile App Design, Minimum Viable Product (MVP), APIs, Identity & Access Management (IAM), Back-end, Mobile Development, Web Development, Microservices, Windows Presentation Foundation (WPF), Unit Testing, ASP.NET Core, Web Content Accessibility Guidelines (WCAG), Web Performance Optimization (WPO), RxJS, WCAG 2, .NET 10, Full-stack Development, Linux, Git, API Integration, Software Engineering, Architecture, Software Architecture, API Design, Back-end Development, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Senior Developer
2016 - 2017
US software company
- Built a Xamarin.Forms on-demand services app for iOS and Android, Uber-style, with live job requests and Firebase push notifications.
- Created a dating app using Xamarin.Forms running on iOS and Android for a Toptal client. Large parts were then reused to create a marketing app running on Android and iOS.
- Developed the ILS app for the iPhone and iPad. This app lets pilots practice their instrument landing system approaches at any airport.
- Built the NextStop app for iOS, Android, and Windows Phone for use by visually impaired people—it announces the next stop that a bus will arrive at.
- Created a REST web service using the Web API that allows the secure downloading of an encrypted SQLite database containing details of nearly 35,000 approaches.
- Created a Microsoft SQL database to provide the data for the REST web service.
Technologies: C#, Xamarin.Forms, Mobile Apps, Mobile GPS, Mobile, Entity Framework, REST APIs, Web Services, Cloud Services, .NET, ASP.NET, Microsoft Visual Studio, SQLite, Xamarin, Microsoft SQL Server, Android, Visual Studio Code (VS Code), Front-end, Mobile App Development, FDA, SQL, Stripe API, Mobile App Design, Minimum Viable Product (MVP), APIs, Identity & Access Management (IAM), Back-end, Mobile Development, Web Development, Microservices, Windows Presentation Foundation (WPF), C++, Mobile App Testing, Unit Testing, Stripe, Web Content Accessibility Guidelines (WCAG), RxJS, WCAG 2, Full-stack Development, Amazon Web Services (AWS), Git, API Integration, GPS, Cross-platform App Development, Software Engineering, Architecture, Software Architecture, Healthcare, iPhone, Security, Solution Architecture, API Design, Back-end Development, Firebase Cloud Messaging (FCM), Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Software Consultant
1996 - 2015
Atos Worldline
- Worked as a senior developer in a team of up to 15 on WebTIS, the train ticket website used by East Coast, First Group, and other UK train operating companies.
- Developed a PCI DSS-compliant card vault holding encrypted card details for a UK rail ticketing website handling over 50,000 transactions and $3 million in sales a day.
- Built the card authorization service, including 3D Secure, that authorized over 50,000 transactions a day.
- Built the site's SQL Server database, with all access through stored procedures.
- Replaced Microsoft CMS, letting the website move off a legacy 32-bit operating system onto modern virtualized servers.
- Designed and built many of the site's pages and services in C#, ASP.NET MVC, and JavaScript, on a service-oriented architecture, delivering on a tight, immovable launch deadline.
Technologies: ASP.NET, C#, JavaScript, Microsoft Visual Studio, Microsoft SQL Server, .NET, Cloud Services, Web Services, Front-end, Documentation, SQL, APIs, Back-end, Web Development, C++, Windows Desktop, Unit Testing, Visual Basic, Full-stack Development, Software Engineering, Architecture, Software Architecture, PCI DSS, Encryption, ASP.NET MVC, OWASP, Service-oriented Architecture (SOA), Model View Controller (MVC), Web API, Security, Solution Architecture, API Design, Back-end Development, Modernization, Cryptography, Front-end Development, Software Development, Software Development Lifecycle (SDLC)
Software Consultant
1995 - 1996
NatWest Home Loans
- Employed to understand and debug this very complex C++ code in order to make the system maintainable.
- Rationalized the existing undocumented C++ code and designed and implemented an understandable method of extending it, significantly improving the ability of the team to respond to requests from management.
- Trained the other team members to maintain the system themselves, and improved development procedures by introducing SourceSafe and better build techniques.
- Received a letter of commendation from senior management for our work in supporting a TV marketing campaign.
Technologies: C++, Windows, Windows API, Unit Testing, Visual Basic, Software Engineering, Solution Architecture, Modernization, Software Development
Software Engineer
1991 - 1993
Technolog
- Wrote the code for the Newlog 4, a gas pressure logger and controller used by British Gas, including at Selsey Bill, in assembler on a 63705 microcontroller.
- Wrote the Windows software in C that talked to the loggers over modems, and worked on site with the customer during testing and installation.
- Brought C to a logger based on a Mitsubishi 377 microcontroller, which made complex monitoring and logging routines much easier to write.
Technologies: Embedded C, Assembly, Embedded Systems, Firmware, Microcontrollers, Software Development
Software Engineer
1988 - 1991
GEC Plessey Telecommunications
- Supported development of the Swingi business telephone exchange, which GPT built and Nokia sold under its own name, writing in C and assembler.
- Built peripherals for testing, including a microcontroller-based converter that let old rotary phones dial into the exchange using DTMF.
- Tested the exchange software during development, working with the development team to find and fix faults before release.
Technologies: Embedded C, Assembly, Embedded Systems, Firmware, Microcontrollers, Software Development
Project History
Schedrix: production sequencing for Microsoft Dynamics 365 Business Central
https://www.capability-systems.com/schedrixSchedrix is a Business Central extension that schedules production runs for each line in food and drink factories, where every changeover costs line time, and allergen cleans can't be skipped. A planner writes a changeover rule in plain English ("moving from a product with milk to one without needs a 45-minute clean"); Schedrix shows how it understands it and uses it only once the planner confirms it. It then proposes a sequence that keeps changeovers short without dropping a required clean. Nothing changes in Business Central until the planner applies the proposal, and Revert reverts it.
I designed the product and architecture and led the build. The AL extension reads production orders, routings, and calendars and calls a Python service on Azure, which interprets rules with Claude and solves the sequence with a constraint solver. It was built for AppSource from the start, with code signing, AppSourceCop, and a local CI gate that runs the AL tests in a Business Central container. I built it through an AI-assisted pipeline I direct: I write the specification and architecture, agents write most of the code, and independent review checks every change.
I designed the product and architecture and led the build. The AL extension reads production orders, routings, and calendars and calls a Python service on Azure, which interprets rules with Claude and solves the sequence with a constraint solver. It was built for AppSource from the start, with code signing, AppSourceCop, and a local CI gate that runs the AL tests in a Business Central container. I built it through an AI-assisted pipeline I direct: I write the specification and architecture, agents write most of the code, and independent review checks every change.
KeepSong: AI-generated Memorial Songs and Films, Sold Through Funeral Directors
https://www.keepsong.co.ukKeepSong turns a family's memories and photos into a personal song and a short film for a funeral or memorial. It is sold through funeral directors as a white-label service, so each director's families see the director's own brand. A family member signs in via a magic link, shares memories, approves the lyrics, then commissions the song; the system writes the lyrics, checks them for safety, generates the song, aligns the words with the music, and builds the film.
I designed and built it end to end. It's a Next.js 16 and React 19 web app with three separate areas for families, funeral directors, and operations staff, and a Node worker that runs the generation pipeline from Azure Service Bus, scaling to zero when idle. Data is in Azure PostgreSQL Flexible Server with Drizzle, and every query is scoped to the funeral director's tenancy, with a CI test proving one director can never see another's families. It runs on Azure Container Apps with Key Vault and managed identities, all in Terraform. I built it through an AI-assisted pipeline I direct, with a local CI gate and independent review on every change, over 2,300 commits.
I designed and built it end to end. It's a Next.js 16 and React 19 web app with three separate areas for families, funeral directors, and operations staff, and a Node worker that runs the generation pipeline from Azure Service Bus, scaling to zero when idle. Data is in Azure PostgreSQL Flexible Server with Drizzle, and every query is scoped to the funeral director's tenancy, with a CI test proving one director can never see another's families. It runs on Azure Container Apps with Key Vault and managed identities, all in Terraform. I built it through an AI-assisted pipeline I direct, with a local CI gate and independent review on every change, over 2,300 commits.
ATrack Mobile App and Website
https://www.atracksolutions.com/A Xamarin app and Angular website with C# and SQL server back end used to provide training and record training outcomes for children with autism-related learning difficulties. I designed and developed the full-stack implementation of this system, which complies with the HIPAA requirements.
Purchase Train Tickets on the British Rail Network
I developed this page and associated purchase pages that allows the purchase of train tickets for use on the British rail network. It uses C#, ASP.NET, and extensive JavaScript. This website sells over $3 million worth of tickets per day on the busiest days.
Fly ILS Approaches Anywhere
This app uses the GPS location and an extensive database of airport runways to simulate an ILS on any runway. The app allows you to create your own ILS anywhere. Choose a convenient ground feature in Google Maps, enter the coordinates and the runway heading and threshold elevation for this feature then practice your ILS skills. Perfect for keeping your skills up-to-date without annoying your local airfield neighbors and without paying any navigation fees.
Education
2019 - 2023
Bachelor's Honors Degree in Business Management
Nottingham Business School - Nottingham, United Kingdom
2001 - 2002
Microsoft Certified Solutions Developer (MCSD) in Computing
Microsoft - Nottingham, UK
1985 - 1988
Bachelor of Engineering (Honors) in Microelectronics and Microprocessor Applications
University of Newcastle upon Tyne - Newcastle upon Tyne, UK
Certifications
MARCH 2017 - JUNE 2019
Xamarin Certified Mobile Developer
Xamarin (Microsoft)
JANUARY 2002 - PRESENT
Microsoft Certified Solution Developer
Microsoft
Skills
Libraries/APIs
Web API, Entity Framework, REST APIs, React, Windows API, Node.js, Stripe, Google Maps, Stripe API, RxJS, OpenAI API, Claude API, SignalR
Tools
Microsoft Visual Studio, Claude, Git, Claude Code, Firebase Cloud Messaging (FCM), Sentry, Terraform, xUnit, xUnit.net, Dynamics 365 Business Central, Google OR-Tools, Azure Application Insights, AI SDK, Azure App Service
Languages
JavaScript, C#, C#.NET, HTML, CSS, TypeScript, HTML5, CSS3, Dart, C++, SQL, Visual Basic, AL, Embedded C, Assembly, Python
Frameworks
ASP.NET, Flutter, Angular, Bootstrap 3+, .NET Core, Redux, .NET, Entity Framework Core, Next.js, ASP.NET Core, .NET MAUI, ASP.NET MVC 5, Riverpod, Windows Presentation Foundation (WPF), ASP.NET MVC, NestJS, Tailwind CSS
Paradigms
Dependency Injection, Service-oriented Architecture (SOA), Model View Controller (MVC), Mobile App Design, Mobile Development, Unit Testing, Test-driven Development (TDD), Management, Model View ViewModel (MVVM), Microservices, Web Performance Optimization (WPO), Constraint Programming, Azure DevOps
Platforms
Xamarin, Windows, Visual Studio 2022, Visual Studio Code (VS Code), Mobile, Azure, Windows Desktop, Linux, Vercel, Android, iOS, Firebase, Docker, Kubernetes, Amazon Web Services (AWS)
Storage
SQLite, Microsoft SQL Server, SQL Server 2016, SQL Server 2019, SQL Server 2017, PostgreSQL, Azure Cloud Services
Industry Expertise
Healthcare
Other
Xamarin.Forms, OWASP, Full-stack, Mobile Apps, Mobile GPS, Cloud Services, Web Services, Front-end, Mobile App Development, Application State Management, Minimum Viable Product (MVP), APIs, Back-end, Web Development, Mobile App Testing, Large Language Models (LLMs), Server-side Rendering (SSR), .NET 10, Full-stack Development, AI Integration, API Integration, Microsoft Azure, GPS, Cross-platform App Development, AI-assisted Development, Software Engineering, Architecture, Software Architecture, Security, Solution Architecture, API Design, AI Systems, Agentic AI Systems, Large Language Model Operations (LLMOps), Orchestration, Back-end Development, Modernization, Front-end Development, Software Development, Software Development Lifecycle (SDLC), iPhone, Encryption, IT Project Management, Firmware, CI/CD Pipelines, Documentation, Artificial Intelligence (AI), AI Agents, Agentic AI, Cloud Architecture, Supabase, AI Tools, Prompt Engineering, Generative Artificial Intelligence (GenAI), Web Content Accessibility Guidelines (WCAG), WCAG 2, GitHub Actions, Agentic Coding, Microsoft AppSource, FastAPI, PCI DSS, Optimization, Embedded Systems, Microcontrollers, Cryptography, FDA, Octopus Deploy, Content Management Systems (CMS), Identity & Access Management (IAM), Gemini API, Vector Databases, OpenAI, RAG Systems, Inngest, Serverless Functions, Anthropic, Image Generation, Manufacturing, Production Planning & Scheduling
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