I build dependable web applications, from the database to the browser.
I'm Callum Peers, founder of Vantara Labs and a senior backend engineer at TheTin. I work mostly in C# and .NET, with Vue and Nuxt on the front end.
The koi pond behind this page is live. Click any open water between the panels to dive in.
Technologies I work with
Grouped by area, strongest first.
Frontend Development
- Advanced
- Vue.js
- Nuxt
- Angular (2+ / AngularJS)
- TypeScript
- JavaScript (ES6+)
- SCSS / Bootstrap
- HTML & CSS
- Tailwind CSS
- Intermediate
- React
- Next.js
- Babylon.js
Backend Development
- Expert
- C# & .NET (Core / Framework)
- ASP.NET (Web API / MVC)
- REST APIs
- Advanced
- SQL Server
- PostgreSQL
- Firebase
- Node.js
- Intermediate
- Stripe
- Cassandra
- WebSockets / WebRTC
- Redis
- Peer-to-Peer Networking
DevOps & Cloud
- Advanced
- Azure
- Google Cloud
- Git & GitHub Actions
- Azure DevOps
- Intermediate
- Terraform
- AWS
- Bitbucket
- SVN
- Docker
- Cloudflare
- Jira
Testing & Methodologies
- Advanced
- Agile / Scrum
- TDD & Unit Testing
- Integration & E2E Testing
- OOP & Design Patterns
- Intermediate
- Secure Coding / App Sec
Featured projects
A few things I've built outside the day job, including the pond this site sits on.
Planning Poker
A real-time planning poker table for agile estimation, built with a friend: join a room, pick a card, and reveal everyone's votes together.
- Angular
- TypeScript
- Socket.io
- Node.js
ScreenShare
A peer-to-peer screen-sharing app: everyone in a room can stream one or more screens at once, straight to each other's browsers over WebRTC.
- Angular
- TypeScript
- WebRTC
- Socket.io
- Node.js
The Koi Pond
The 3D pond behind this site. Sail a small boat, cast a line, and fill in the Koi Journal as you catch each variety.
- Babylon.js
- TypeScript
- Nuxt 3
Where I've worked
I founded Vantara Labs, a UK software company that builds and runs its own web products, alongside my role at TheTin. I do the engineering end to end: product code, infrastructure, billing, releases and operations.
- Manage every Google Cloud project, IAM binding, budget alert, Cloudflare DNS record and the Stripe product catalogue as code in Terraform, with a reviewed plan for every change
- Deploy from GitHub Actions with keyless Workload Identity Federation instead of long-lived service-account keys
- Built the company website (vantaralabs.co.uk) as a statically generated Nuxt site with a Firebase contact function
- Run a self-hosted knowledge and memory service for the AI coding agents I work with, reachable only over a private Tailscale network
- Nuxt
- Vue.js
- TypeScript
- Firebase
- Google Cloud
- PostgreSQL
- Terraform
- Stripe
- Cloudflare
- GitHub Actions
Senior Backend Engineer
TheTin Ltd
Mar 2023 – Present·Remote / London, UK
Key member of the backend team building and maintaining a suite of client-facing products. Lead several legacy-to-modernisation projects (incl. full migration from .NET Framework to current .NET versions), drive cost-optimised cloud hosting solutions and own the release pipeline end-to-end.
- Migrated a mission-critical legacy app to modern .NET and GitHub Actions, cutting build-and-deploy time from hours to minutes
- Designed and implemented hosting changes that trimmed cloud spend by >30 %, then documented the approach for future projects
- Took ownership of multiple existing applications, stabilising defect backlog and improving maintainability
- Regularly liaise with project managers to turn client requirements into technical deliverables
- C#
- ASP.NET
- .NET Core / .NET 8
- SQL Server
- Git (GitHub & Bitbucket)
- GitHub Actions
- Vue.js
- Node.js
- TypeScript
- SCSS
- Azure
Backend Software Engineer
Codeweavers Ltd
Sep 2017 – Feb 2023·Dunston, Staffordshire, UK
Developed scalable SaaS solutions for the automotive industry in a fast-moving agile environment. Split time between core feature work and the dedicated Software Security team, integrating automated security checks and driving compliance initiatives.
- Piloted and rolled out security-scanning tools in the CI pipeline, catching critical issues pre-production
- Facilitated cross-team compliance workshops that closed multiple audit gaps ahead of deadline
- Actively practised and promoted pair-programming, boosting code quality and knowledge-sharing
- C#
- ASP.NET
- .NET Core
- PostgreSQL
- SQL Server
- Cassandra
- Angular 2+ / AngularJS
- Node.js
- TypeScript
- SCSS / Bootstrap
- SVN → Git migrations
- CI/CD (Azure DevOps)
- Jira
- TDD / Unit, E2E & Integration testing
Indie Developer
Personal Projects
2015 – Present·Staffordshire, UK
Side projects I build to learn things properly, from Discord and Telegram bots to real-time web apps.
- Built LightBot, a sharded Discord music bot with a companion website for controlling playback (2018–2020)
- Built ScreenShare, a peer-to-peer WebRTC app where everyone in a room can stream several screens at once (2019–2021)
- Co-wrote Planning Poker, an open-source real-time estimation table for agile teams (2022)
- Node.js
- Angular
- TypeScript
- WebRTC
- Socket.io
- Discord.js
- SQLite
- Docker
Get in touch
Want to talk about something I've built, an idea or a role? Send me a message, or find me on GitHub and LinkedIn.