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We build software that defies expectations. Full-stack development, AI-powered platforms, and systems that actually work — shipped fast, built to last.
From concept to production — we handle the full lifecycle of modern software systems.
End-to-end web applications built with React, TypeScript, Node.js, and modern tooling. Production-grade code from day one.
Intelligent systems with LLM integration, smart automation, and AI assistants that actually add value to your workflow.
Multi-tenant platforms built for scale. Auth, billing, admin dashboards, and the infrastructure to support real growth.
Clean API design, third-party integrations, and system interconnections. tRPC, REST, WebSockets — whatever the job needs.
Infrastructure that doesn't keep you up at night. CI/CD pipelines, containerisation, monitoring, and reliable deployments.
Hardened auth flows, row-level security, rate limiting, CSP headers, and performance tuning for real-world load.
HTTP 417 fires when reality doesn't match expectations. We took that as a name because we don't build what people expect — we build what they actually need.
Error 417 is a development studio specialising in AI-powered platforms, SaaS products, and complex full-stack systems. We move fast, ship clean code, and obsess over the details that separate prototypes from products.
Based in London. Working with clients who want software built properly the first time.
Two platforms, one philosophy — software that actually works for real people.
A comprehensive, modular SaaS platform that brings together AI assistance, financial management, wellness tracking, learning systems, IoT control, and more — all under one intelligent roof. Built from the ground up with a dual-database architecture and production-grade security.
Conversational AI with streaming responses, proactive suggestions, and a Skills Manager that keeps costs low by injecting only relevant context.
Budget tracking, expense categorisation, and financial insights — all secured with row-level security and encrypted storage.
Adaptive learning systems and real-time translation, powered by intelligent AI that personalises to each user.
Health metrics tracking, wellness insights, and personalised recommendations — integrated across the platform.
Unified device control and automation, bridging the gap between your digital assistant and physical environment.
A real-time multilingual communication platform that breaks language barriers instantly. Speak in your language, be understood in theirs — with an optimised speech pipeline delivering sub-4-second end-to-end translation latency. Deployed multi-region for global reach.
Optimised speech-to-speech pipeline — speak naturally and hear the translation in near real-time with sub-4s latency.
Built around natural conversation, not text boxes. Google Cloud TTS delivers natural-sounding voice output across languages.
Fly.io edge deployment ensures low latency wherever your conversation partners are in the world.
Full security audit complete with 26 findings addressed. Production-grade auth and data protection from day one.
Battle-tested technologies. No hype-driven choices — every tool earns its place.
Tell us what you're building. We'll tell you how we'd ship it.
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