RAG evaluationservices for systems that sound sure of themselves, and are wrong too often.

Your RAG system is live or close to it, and people have stopped trusting its answers. We measure it on your own questions, show which step fails (the source content, chunking, retrieval or the prompt), fix that step and leave you with checks that run on every change.
Get your RAG system measured

"It feels better now" is not a measurement. A test set is.

Many RAG teams tune by trying a few questions after each change and judging the answers by eye. That hides regressions: the change that fixed one question quietly broke others. Evaluation replaces the impression with a fixed set of questions, known correct answers and a score for each step of the pipeline, so you can see what a change did before users do.

Why RAG answers go wrong

01

The right passage is never retrieved

The answer exists in your documents, but search returns other chunks. The model then answers from what it was given, or from its own memory.
02

Chunks cut the meaning in half

A table is split from its header, a clause from its exception, a step from the procedure it belongs to. Each piece is retrieved without the part that makes it true.
03

The sources disagree with each other

An old policy and its replacement both sit in the index. The system picks one, and nobody can say which one it will pick tomorrow.
04

The model answers anyway

When retrieval finds nothing useful, the prompt does not tell the model to say so. Users get a fluent answer with no basis in your content.
05

Every fix breaks something else

A new chunk size or prompt improves the questions you tried and worsens the ones you did not. Without a regression set you find out from complaints.
06

Nobody tested what it should refuse

Documents can carry hidden instructions, and retrieval can return content the person asking is not allowed to see. These risks stay invisible until someone looks for them.

Four places a wrong answer comes from

We score each stage separately. A single overall score tells you the system is bad, not what to change.

Source content

  • Outdated and duplicate documents
  • Pages that contradict each other
  • Text lost when PDFs and tables are parsed

Chunking and indexing

  • Chunks that split tables, lists and clauses
  • Missing titles, dates and document type
  • An index that lags behind the documents

Retrieval

  • The relevant passage is not in the results
  • Exact terms and product codes that vector search can miss
  • Good results ranked below weak ones

Generation

  • Claims the retrieved text does not support
  • No "I don't know" when context is missing
  • Answers that ignore part of the question

Signs your RAG system needs an evaluation

Any one of these means you are making decisions about the system without data.

1

You cannot state its accuracy

When leadership asks how often the answers are correct, the honest reply is "we don't know".

2

Users check every answer

People open the source document after each reply, so the system saves them no time.

3

The same question, different answers

Small changes in wording produce replies that contradict each other.

4

Citations point to the wrong place

The answer links to a document that does not say what the answer claims.

5

A model or library upgrade is waiting

You want to switch the model, the embeddings or the vector store and have no way to compare before and after.

6

Security has started asking questions

Nobody can show who is able to retrieve which documents, or what happens when a document contains instructions for the model.

What the work consists of

RAG evaluation and optimization, step by step

Test set from real questions

We collect questions from your logs and your subject experts, write the expected answer and the passage that supports it, and add questions the system should decline.

Retrieval measurement

For each question we check whether the supporting passage is retrieved and how high it ranks. That gives recall and ranking scores for the search step alone.

Answer quality measurement

We score answers for correctness against the expected answer and for faithfulness: every claim must be supported by the retrieved text.

Judge calibration

Automated scoring with an LLM judge is fast, but it has to agree with people. We compare it with human grades on a sample and adjust it before trusting its numbers.

Root cause analysis

Each failed question is assigned to a cause: content, parsing, chunking, retrieval, ranking or prompt. You see which cause accounts for most failures.

RAG optimization

We fix the largest causes first: chunking strategy, metadata, hybrid search, reranking, query rewriting, prompts. Each change is rerun against the full test set.

RAG content optimization

We list the documents that produce wrong answers (outdated, duplicated, contradictory or badly parsed) and tell your content owners what to fix, merge or remove.

RAG risk assessment

We test prompt injection through user input and through documents, check that retrieval respects user permissions, and review what personal data lands in logs and prompts.

What you have at the end

The results stay with you: in your repository, running in your pipeline, readable by people who were not in the project.

A baseline and a findings report

Scores for retrieval and for answers, per question type

Failed questions grouped by cause, with examples

A ranked list of fixes with expected effort

A test set and regression checks

The test set in your repository, in a plain format

An evaluation run in CI on every pipeline change

Before and after scores for each fix we make

A risk register

Prompt injection tests and their results

Permission checks on retrieval, per user role

Data-leak paths found, with a fix for each

Tools we work with

We evaluate the system you already have, whatever it is built on. The evaluation code is usually Python and runs in your CI. The evaluation framework, the judge model and any tracing tool are chosen with you per project, for example between an open-source library such as Ragas or DeepEval and a small custom harness.

Python
FastAPI
PostgreSQL
Node.js
Docker
AWS
Kubernetes
TypeScript
Who is this for

For teams that already have a RAG system

Product companies

A RAG feature is in your product and customers report wrong answers. You need to know how bad it is and what to fix first.

Founders

Your prototype impressed in the demo and now fails on real documents. You need numbers before the next release or investor update.

Internal tools teams

Employees stopped using the knowledge assistant. You need evidence to decide between repairing it and replacing it.

Security and compliance leads

You have to sign off on a system that reads internal documents and want its injection and access risks tested first.

Where do you need help?

Measure what we have

A baseline for retrieval and answer quality on your questions.

Find the cause

Know which pipeline step produces most wrong answers.

Fix retrieval

Chunking, hybrid search, reranking and metadata, tested against the baseline.

Clean the content

A list of documents to update, merge or remove.

Stop regressions

An evaluation run on every change, before release.

Assess the risks

Prompt injection, permissions and data leaks tested and documented.

From "it seems off" to a measured, fixed system

01

Access and scope

We get read access to the pipeline, the index and the logs, and agree which question types and user roles matter most.

02

Test set

We draft questions, expected answers and supporting passages. Your subject experts review them, because only they know what a correct answer is.

03

Baseline

We run the current system against the test set and score retrieval and answers separately. You see the numbers before any change is made.

04

Diagnosis

Failures are grouped by cause and ranked by how many questions each cause affects. We agree on the order of fixes with you.

05

Fix and re-measure

One change at a time, each rerun against the whole set, so every gain and every regression is visible.

06

Regression checks

The evaluation moves into your CI, with a threshold you choose, and your team gets a walkthrough of how to extend the test set.

How we work

Choose how to start

Discovery Sprint

most popular

2-week fixed-price start

Fixed price.

For teams that need a baseline and a diagnosis before deciding what to fix.

First test set from your questions

Baseline scores for retrieval and answers

Failures grouped by cause

Initial injection and permission checks

Ranked fix plan with an estimate

Start with a baseline

Optimization team

Engineers working through the fix plan

Monthly, team-based.

For systems that need sustained work: retrieval changes, content cleanup and checks in CI.

Python and backend engineers

QA for test sets and answer grading

Fixes measured against the baseline

Evaluation wired into your CI

Regular demos with before and after scores

Discuss your system

AI products we've built and rescued

Data MANAGEMENT & payroll

AI Payroll Platform (NDA)

Europe

An AI-powered payroll validation platform that extracts data from salary slips, verifies payroll calculations, and automates reporting and approval workflows for HR and finance teams

Before
→
after
↓
Manual payroll validation
↑
17% fewer salary calculation errors
↓
Complex PDF extraction
↑
AI-powered PDF data extraction
↓
Manual approval workflows
↑
Automated payroll validation and reporting workflows
↓
 Limited processing scalability
↑
Scalable platform for payroll processing
AI CONSUMER APPS

AI Mobile Editors

Global
4M+
DOWNLOADS COMBINED
Before
→
after
↓
Existing  codebase required stabilization
↑
Both apps stayed instore
↓
AI features broken or misleading
↑
AI rebuilt to production quality
↓
App Store compliance at risk
↑
App Store compliance restored
↓
Reviews declining fast
↑
Product stabilized 
AI Commerce PlatformE

QLode

USA
Europe

An AI-powered fashion commerce platform that helps retailers deliver personalized shopping experiences through virtual styling, AI recommendations, image search, and intelligent product discovery.

Before
→
after
↓
AI search didn't scale
↑
AI-based recommendation engine developed
↓
Scalable infrastructure needed
↑
Image & text search implemented
↓
Complex retailer integrations
↑
Multi-retailer integration architecture built
↓
Product discovery wasn't production-ready
↑
High-performance backend for AI-driven flows

What clients say about working with Gilzor

Verified reviews from Clutch. The subject changes from project to project, the way we work does not.

“They were incredibly fast and efficient at scoping the project and then delivered within very tight deadlines.”
Clement Nevoret CEO, Pointblank GmbH Mobile app development · $10,000 to $49,999 Verified review on Clutch
“I was impressed with how quickly we got a stable and well-designed product.”
Natalia Burakova Senior Product Manager, Impala Studios Mobile app development and support · $200,000 to $999,999 Verified review on Clutch
“The team met all commitments, aligning with our company's objectives.”
Verified client Individual entrepreneur, IT company Mobile app, API and UX/UI design · $50,000 to $199,999 Verified review on Clutch

The people you will talk to

Art Scherbakov
Art ScherbakovCo-Founder
Andrew Laminsky
Andrew LaminskyCTOLinkedIn
Yuri Rudenya
Yuri RudenyaHead of Mobile Development at GilzorLinkedIn
Alena Timofeeva
Alena TimofeevaProduct Marketing LeadLinkedIn

Make the most of the experienced team

We are a global team of
creative
and
strategic thinkers
who specialize in building custom digital products
from scratch. Our main goal is to
deliver high-quality solutions
that meet our clients' needs.
We are a global team of
creative
and
strategic thinkers
who specialize
in building custom digital products
from scratch. Our main goal is to
deliver high-quality solutions
that
meet our clients' needs.
Learn more
85%
recurring customers
12M
the biggest fundraising round by one startup
X3 MRR
growth of partner's business in 5 mos
2 weeks
for project start
5+ years
av. partnership duration with SMBs and product companies

Why Gilzor

We treat a RAG system like any other software that has to be correct: define what correct means, test for it, fix what fails and keep the tests.

What we bring

AI work measured by errors

On an AI payroll platform we built, automated extraction and validation of salary slips led to 17% fewer salary calculation errors.

Experience fixing AI features

For two AI editor apps with 4M+ downloads combined, we rebuilt the AI features to production quality.

Engineering and QA in one team

Python and backend engineers work next to QA, so the people who measure can also fix.

Track record

70+ products launched for startups, SMBs and product companies. 85% of clients come back.

Quick start

Projects can start in about two weeks.

What makes us different

Numbers before opinions

We change nothing until there is a baseline to compare against.

No promised score

We do not quote an accuracy target before measuring. Some limits come from the content, and we say so.

Your experts decide what is correct

We build the test set, your people approve the expected answers.

Nothing locked to us

Test set, evaluation code and reports live in your repository.

Overlap with US hours

Our team in Europe overlaps with part of the US working day.

What our clients
frequently ask

What do your RAG evaluation services include?

A test set built from your real questions, separate scores for retrieval and for answers, a diagnosis that assigns each failure to a cause, and a ranked fix plan. If you continue with us, we make the fixes, re-measure after each one and put the evaluation into your CI. A risk assessment covering prompt injection, permissions and data leaks can be part of the same work.

How many test questions do we need?

Enough to cover each question type and user role with several examples, which depends on how varied your content is. We start with a smaller set to get a first baseline quickly and grow it as failures show where coverage is thin. Quality matters more than size: each question needs an expected answer and a supporting passage that your experts have approved.

Which metrics do you measure?

For retrieval: whether the supporting passage is in the results (recall) and how high it ranks. For answers: correctness against the expected answer, faithfulness to the retrieved text, and whether the system declines when it should. We report them separately, because a system can retrieve well and still answer badly, and the fix is different in each case.

Can an LLM grade the answers, or do people have to?

Both. An LLM judge makes it practical to rerun hundreds of checks after every change, but its grades are only useful if they match human judgment. We have people grade a sample, compare the judge against them, adjust the judge's instructions and keep a human review for the question types where it stays unreliable.

We did not build the system ourselves. Can you still evaluate it?

Yes. For a system built by another vendor or on a managed platform, we need a way to send questions and see the answers with the retrieved passages. If the platform does not expose the retrieved passages, we can still score answers end to end, but the diagnosis is less precise, and we tell you that at the start.

What does RAG optimization usually change?

It depends on where the failures are. Common changes are a chunking strategy that keeps tables and sections intact, metadata filters, combining keyword and vector search, a reranking step, rewriting the user's query, and a prompt that requires answers to stay within the retrieved text. Sometimes the largest gain is content cleanup rather than code.

What does a RAG risk assessment cover?

We test whether instructions hidden in user input or in indexed documents can change the system's behavior, whether a user can retrieve content outside their permissions, and what personal or confidential data ends up in prompts, logs and third-party services. You get the test cases, the results and a fix for each finding. It is a technical assessment, not a formal compliance audit.

How is the work priced?

The Discovery Sprint is a 2-week fixed-price engagement that ends with a baseline, a diagnosis and an estimate for the fixes. After that, a defined set of fixes can be a fixed price for the agreed scope, and ongoing optimization is billed monthly for a team.

No sales pitch

Tell us what your RAG system gets wrong

Describe what it is built on, what content it reads and a few questions it answers badly. We'll come back with how we would measure it and a quote for the baseline.

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