We build software that ships — at scale.
Revenant Systems is a UK software consultancy built on twenty years of engineering high-throughput, real-time systems — platforms that process billions of events a month. We work directly with startups, growing companies, and established SMEs where software, data, infrastructure, or spreadsheets have become business-critical. Senior engineers, in-house. Quietly. Correctly. On time.
Why teams call us
Something else? Let's talk →- “Our AI feature works in the demo but fails with real users.” AI Production-Readiness Audit →
- “Our AWS bill has grown faster than our traffic.” Cloud Cost Audit →
- “PostgreSQL is slow and nobody knows why.” PostgreSQL Performance Audit →
- “We've inherited a system nobody understands.” Legacy System Rescue Assessment →
- “The business runs on a spreadsheet we're scared to change.” Excel Workbook Audit →
- “We need a senior team to build the product properly.” Full-Stack Development →
Services
View all services →Full-Stack Application Development
Production web applications built end to end — data model, API, and interface. Go, Node.js and Python on the back end; Astro and HTMX for fast, lean front ends — and cross-platform mobile apps when you need to reach iOS and Android.
Go · Node.js · Python · Astro · HTMX · React Native · ExpoAI Consultancy
Practical AI integration — model selection, agent design, and LLM features built to hold up in production, not just in a demo. We also expose your existing applications to LLMs as tools agents can drive, automating workflows that used to take a person.
Anthropic · OpenAI · Google · OpenRouter · Python · Pydantic · LMStudio · llama.cppData Engineering & Analytics
The full data path — tracking and ingestion pipelines through to dashboards and reporting systems that turn raw events into decisions.
Python · PostgreSQL · ClickHouse · DuckDB · Data Warehousing · AirflowPackages
View all packages →Cloud Cost Audit
A fixed-price audit of an AWS estate's spend — where the money goes, what's over-provisioned, idle, or architecturally expensive — delivered as a severity-ranked report and a prioritised savings roadmap.
Excel Workbook Audit
A fixed-price analysis of the Excel workbooks your business actually runs on — what they do, where they're fragile, and a clear route to fixing or replacing what the audit finds.
PostgreSQL Performance Audit
A fixed-price, fixed-scope audit of a production PostgreSQL database — query load, indexing, autovacuum, configuration, and cost — delivered as a severity-ranked report and remediation roadmap.