Custom RAG developmentservices for answers that come from your own documents, with the source attached.

We build the whole retrieval-augmented generation system: connectors to your content, parsing and indexing, retrieval, the answer step with citations, a test set that shows whether answers are right, and the deployment in your cloud. One team, from the first data review to production.
Discuss your RAG project

The model is rarely the problem. What it was given to read usually is.

A RAG system answers from the passages it retrieves. If the right passage was never indexed, was cut in half, or lost out to an outdated copy, the model writes a confident answer from the wrong text. So most of the work is not prompt writing. It is parsing your documents properly, finding the right passages for each question, and measuring both steps on real questions before users see anything.

Where RAG projects go wrong

01

Documents are parsed badly

Tables, scanned PDFs, multi-column layouts and slide decks turn into scrambled text, and nobody notices until the answers are wrong.
02

The right passage is not retrieved

Vector search alone often misses exact terms such as product codes, names and clause numbers. Without keyword search and reranking, the answer step may never see the correct text.
03

Chunks lose their context

A paragraph split away from its heading, date or product name reads the same as a paragraph about something else.
04

Old and duplicate content wins

Three versions of the same policy sit in the index, and the system quotes the one that was replaced last year.
05

People see what they should not

The index ignores the permissions of the source system, so an answer can quote a document the person asking is not allowed to open.
06

Nobody can say if it got better

Changes are judged by trying a few questions by hand. A fix for one question quietly breaks ten others.

What you have when we finish

A RAG system you can run, change and check without us.

Numbers, not impressions

  • A test set made from your own questions
  • Scores for retrieval and for answers
  • A list of known weak spots and why they are weak

Answers people can verify

  • Answers link to their source passages
  • A "not found" reply when the evidence is missing
  • Access rules applied before the model sees anything

An index that stays current

  • New and edited documents picked up automatically
  • Deleted and replaced documents removed
  • Failed files reported, not silently skipped

Full ownership

  • Code in your repository
  • Infrastructure and model accounts in your name
  • Documentation and a handover session for your engineers

Signs you need a custom RAG system

An off-the-shelf assistant is fine for a small, clean set of files. These are the points where teams usually need something built for their data.

1

Your prototype impressed, then disappointed

The demo on twenty files worked. On the full document set, answers became vague or wrong.

2

Content lives in many systems

Answers depend on a wiki, a ticket system, shared drives and a database, each with its own format and access rules.

3

Wrong answers have a cost

Support, legal, finance or operations staff act on what the system says, so every answer needs a source they can open.

4

Access rules matter

Different teams, customers or tenants must only get answers from the content they are allowed to see.

5

Content changes every day

New documents, edits and deletions have to reach the index quickly, without re-processing everything.

6

You need it inside your own product

The answers have to appear in your app, with your login, your design and your usage limits, not in a separate chat tool.

What we do

RAG development services, from raw documents to production

Data and use-case review

We read a sample of your content and your users' real questions, and tell you what RAG can answer well, what it cannot, and what has to be cleaned first.

Connectors and ingestion

Pipelines that pull content from your systems, parse it, split it and keep the index in step with the source as documents change.

Retrieval design

Hybrid search, reranking, metadata filters and query rewriting, tuned on your questions until the right passages come back.

Answer generation

Prompts and model choice for answers that stay inside the retrieved text, cite it, and say so when the documents do not cover the question.

Evaluation

A test set built with your subject experts, scoring for retrieval and for answers, and a report you can read without an ML background.

Permissions and security

Per-user and per-tenant filtering at retrieval time, safeguards against instructions hidden in documents, and control over what reaches a model provider.

Deployment

An API and infrastructure in your cloud account, with environments, CI, monitoring and a way to roll back a bad change.

Application and integration

A search or chat interface, or an API your own product calls. Web and mobile clients come from the same team.

The five parts of a RAG system we build

Each part can fail on its own, so each one is built and tested separately before we judge the whole.

Ingestion and indexing

Connectors to your drives, wikis, ticket systems and databases

Parsing of PDFs, scans, tables and slides, checked on your files

Chunking that keeps headings, dates and document titles

Incremental sync: edits and deletions reach the index

Source permissions stored with every chunk

Retrieval

Keyword and vector search combined

Reranking of candidates before the answer step

Filters by date, document type, team or customer

Query rewriting for follow-up and vague questions

Results limited to what the user may see

Answer generation

Answers grounded in the retrieved passages

A link to the source next to each claim

A plain "not found in your documents" when evidence is missing

Model chosen by quality, speed and cost on your questions

Retrieved text handled as data, with checks against hidden instructions

Evaluation and operations

A test set of real questions with expected answers and sources

Retrieval and answer quality scored separately

The test set re-run on every change

Logging of questions, retrieved passages and answers

Cost and response time tracked per request

Technologies we build RAG systems with

Python and FastAPI for pipelines and the API, PostgreSQL for data, AWS, Docker and Kubernetes for deployment. The vector store, the orchestration library and the model provider are chosen with you per project: for example PostgreSQL with a vector extension or a dedicated vector database, a library such as LangChain or LlamaIndex or plain code, a hosted model or one you run yourself.

Python
FastAPI
PostgreSQL
AWS
Docker
Kubernetes
TypeScript
React
Who is this for

For teams that need answers from their own content

Product companies

You want document Q&A or search inside your SaaS product, with each customer's data kept apart.

Mid-size and enterprise teams

Staff lose hours searching policies, contracts, manuals and tickets spread across systems with different access rules.

Founders

Your product idea depends on accurate answers from a specific body of knowledge, and a demo is not enough for customers.

Teams with a stalled prototype

An internal proof of concept exists, but accuracy, permissions or cost keep it from going live.

Where are you now?

Not sure RAG fits

Check it on a sample of your data first.

Starting from zero

Build the full system, end to end.

Prototype exists

Turn it into something you can release.

Live but unreliable

Measure it, find the cause, fix it.

Adding to a product

Connect RAG to your app and data.

Short on engineers

Outsource RAG development to one team.

How a RAG project runs

01

Data and question review

We look at real documents and real questions, agree what a correct answer is, and write down what is out of scope.

02

Test set and baseline

Together with your experts we collect questions with expected answers and sources, then measure a simple first pipeline against them.

03

Pipeline build

Ingestion, retrieval and generation are improved one at a time, with the test set re-run after each change so you see what helped.

04

Permissions and integration

Access rules, the API, the interface or the connection to your product, and security checks on documents and prompts.

05

Pilot and release

A limited group uses it on real work. Their failed questions go into the test set, then we release to everyone with monitoring in place.

06

Operate and improve

New sources, model updates and content changes are handled against the same test set, by us or by your team after handover.

How we work

Choose how to start

RAG Discovery Sprint

most popular

2-week fixed-price start

Fixed price. The build is quoted after it.

For teams that want proof on their own data, and a clear scope, before committing to a full build.

Review of your sources and access rules

First test set from your real questions

Baseline pipeline on a sample of your data

Architecture and running-cost outline

Scope and estimate for the full system

Start with discovery

Dedicated RAG team

Engineers and QA on your system, month by month

Monthly, team-based.

For the full build and for live systems that keep getting new sources, users and requirements.

Python and backend engineers

Web and mobile developers when you need an interface

QA for answers as well as for the app

Test-set results shared at every demo

Team size adjusted as the scope changes

Discuss your team

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 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
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 

What clients say about working with Gilzor

Verified reviews from Clutch. The projects differ, the way we work is the same.

“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

RAG is mostly data engineering, search and testing around a model. That is the kind of work we do on AI products.

What we bring

AI on real documents

For an AI payroll platform we built PDF data extraction from salary slips with automated validation. Salary calculation errors fell by 17%.

Search experience

For QLode, an AI fashion commerce product, we built image and text search and the backend behind its AI-driven flows.

Products shipped

70+ products launched for startups, SMBs and product companies.

Clients who return

85% of our clients come back with new work.

Quick start

Projects can start in about two weeks.

What makes us different

Test set before tuning

We agree how quality is measured before we change anything.

Plain reporting

You see which questions fail and why, not just an average score.

No lock-in

Vector store, framework and model are chosen for your case and can be swapped.

Honest about limits

If plain search or a simpler tool would do the job, we tell you.

Overlap with US hours

Our team in Poland shares part of the US working day for calls and demos.

What our clients
frequently ask

What do custom RAG development services include?

The full system: connectors to your content, parsing and indexing, retrieval, answer generation with citations, a test set and scoring, access control, deployment in your cloud and the interface or API people use. You can also hire us for one part, for example to fix retrieval in a system you already have.

How do you know the answers are correct?

We build a test set of real questions with expected answers and source passages, written with people who know the subject. Retrieval is scored on whether the right passage came back, and answers on whether they match the source and cite it. The set is re-run on every change, so a regression shows up before release.

Do we need a vector database?

Not always a separate one. For many document sets, a vector extension in PostgreSQL next to keyword search is enough and keeps operations simple. A dedicated vector database makes sense with very large indexes or heavy filtering needs. We test the options on your data and decide with you.

Should we use RAG or fine-tune a model?

RAG fits when answers must come from content that changes and must be traceable to a source. Fine-tuning changes how a model writes or behaves, but it does not keep facts current and cannot show where an answer came from. Many systems need only RAG, and some combine both. Our RAG consulting page covers this decision in detail.

Is this suitable for enterprise RAG development, with access rules and sensitive data?

Yes, that is a design input from day one. Permissions from the source systems are stored with the indexed content and applied at retrieval time, so the model does not receive text the user may not see. We agree with you where data is stored and which model providers may process it, including the option of models that run inside your own infrastructure. We do not make compliance claims on your behalf.

How long does a RAG project take?

It depends mainly on the number of sources, the state of the documents and the access rules. The 2-week Discovery Sprint ends with a baseline measured on your data and a timeline for the full build, so you get a figure based on your content and not on a guess.

How are RAG development services priced?

The Discovery Sprint is a fixed price. The build is then quoted as a fixed price for an agreed scope or as a dedicated team billed monthly. Model usage and hosting are separate running costs, paid by you to your providers, and we estimate them during discovery.

Can we outsource RAG development and still own the result?

Yes. Code lives in your repository, infrastructure and model accounts are in your name, and the test set and documentation are part of the handover. Your engineers can take the system over, or we keep operating it with you.

No sales pitch

Tell us about your documents and questions

What content should the system answer from, who will ask, and what do you have today? We'll reply with a suggested approach and a quote. If RAG is the wrong tool, we'll say so.

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