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LlamaIndex Development · London

LlamaIndex Development in London

Building retrieval systems on LlamaIndex for London organisations, where the index is the product. A capable model given the wrong three paragraphs will answer confidently and wrongly, so how documents are split, enriched and ranked determines quality far more than which model sits at the end of the pipeline.

Why this comes up

The problem

The system retrieves passages that mention the right words and miss the passage that actually answers the question.

What you get

What we deliver

  • Chunking designed around document structure rather than a fixed character count
  • Metadata attached at ingestion so retrieval can filter as well as match
  • Hybrid retrieval where keyword and semantic search each cover the other's gaps
  • Reranking applied when the first pass returns plausible but unhelpful passages
  • Source attribution returned, so answers can be checked against the document
  • Ingestion built to re-run, because documents change and indexes go stale

Want this scoped for your business in London?

Thirty minutes, no charge, no sales script. You leave with a written summary of what llamaindex development would actually involve — whether or not you use us.

Book a 30-minute call

Working in London

London

London clients usually come to us because they want senior people actually on their project rather than a large agency's B team, and because Midlands rates buy considerably more delivery per pound.

Clients here are usually replacing an agency, and want senior people on the work at rates that are not Central London rates.

Sectors we work with in London

  • Financial Services
  • Professional Services
  • Technology
  • Media
  • Hospitality
  • Retail

What we work with

Technologies and platforms

  • LlamaIndex
  • Python
  • pgvector
  • Claude API

Who we work with

Industries we serve

  • Professional services
  • Legal services
  • Financial services
  • Healthcare
  • Technology companies

Why us

Why London businesses choose Asionis

  • Projects typically launched within 4–8 weeks
  • No long-term contracts required
  • All team members UK-based
  • Dedicated account manager and development team
  • Transparent reporting with monthly performance metrics
  • Scalable from startup to enterprise

How we work

  1. Step 1

    Free consultation

    A 30-minute call to understand the problem. You keep the written summary either way.

  2. Step 2

    Proposal

    Scope, timeline and a fixed price, in writing, before anything starts.

  3. Step 3

    Build

    Short cycles with regular check-ins, so you see progress rather than hear about it.

  4. Step 4

    Launch and support

    We handle the go-live and stay available afterwards.

LlamaIndex Development in London — common questions

Why does chunking matter so much?
Because it decides what can be retrieved together. Splitting on a character count cuts tables in half and separates a heading from the paragraph it governs, so the retrieved fragment lacks the context that made it meaningful in the document.
What does metadata add?
The ability to narrow before matching. Document type, date, department and status let a query about current policy exclude superseded versions entirely, which solves a class of wrong answer that no amount of better semantic matching will fix.
Is semantic search enough on its own?
Usually not. It handles paraphrasing well and struggles with exact terms — product codes, names, specific clauses — where keyword matching is precise. Running both and combining the results covers considerably more question types than either alone.
How do we keep the index current?
Treat ingestion as a pipeline that runs, not a task that was done. Source documents change, and an index built once will confidently answer from a version that was superseded months ago — with no signal to the user that it has done so.
Do you work with businesses across Greater London?
Yes. We are based in Leicester, United Kingdom and work with clients throughout London, including London and the surrounding Greater London area. Most collaboration happens remotely, and we travel for kick-offs and key milestones.
What kind of London businesses do you usually work with?
Clients here are usually replacing an agency, and want senior people on the work at rates that are not Central London rates. Beyond that we work across Financial Services, Professional Services, Technology, Media, Hospitality and Retail.
Do you cover the areas around London?
Yes — we work throughout London, including Reading, Milton Keynes, Cambridge, Brighton. London is an urban area of roughly 9,000,000+, and we take on work across the wider Greater London region rather than the city boundary alone.

Talk to us about LlamaIndex Development in London

A 30-minute call with someone who would actually work on it. No sales script, no obligation.

  • Projects typically launched within 4–8 weeks
  • No long-term contracts required
  • All team members UK-based
  • Dedicated account manager and development team
  • Transparent reporting with monthly performance metrics
  • Scalable from startup to enterprise

Or reach us directly

07707 771599admin@asionis.com

Leicester, United Kingdom