Ivan MatiushkinIntegrations, automation and internal systems for businesses

Ivan Matiushkin · Independent contractor · Poland / remote

Internal business applications and reliable data integrations

I build approval workflows, improve existing software and make data imports traceable. We agree on the result and acceptance checks before work starts.

Find your starting point ↓Describe your problem

No introductory call required. Start with a written description.

From fragments to structure — a visual metaphor.

Data reconciliation · first engagement

Two files. One discrepancy report.

When orders, invoices or payments disagree across two systems, I compare two CSV or XLSX files for one agreed period.

What you get An HTML report and Excel workbook with missing records, duplicates and amount differences. You can trace each discrepancy to its source rows.

Request a quote for your comparison →View a sample report

Start with a description of both files and an approximate row count. We agree on scope, price and timing before you order.

01 / Find your starting point

From your situation to working software.

A new application, a change to existing software or a better flow of data. Explore how I can help, with a concrete example for each direction.

Your situation is different? Describe your situation →

02 / Capabilities and examples

Independent examples with test data. They show the implementation approach, not client deployments.

01 / INTERNAL APPLICATIONS

Your work needs a tool of its own.

Requests in email, decisions in chat and statuses in a spreadsheet. Your team needs one place to see what is happening and who owns the next step.

What I can buildAn application with forms, roles, case statuses and decision history, built around your process.

An example to explore

Operations Desk

Create a request, approve it as a manager and inspect the history with named participants. Switch organization to check that its records stay separate.

Next.js / TypeScript · Node.js / Fastify · PostgreSQL / Prisma · Redis / BullMQ

Try the live demo ↗Discuss a similar task →
Code and tests ↗Verification results ↗Open the example →

No account needed · a separate visitor workspace · English UI. Approvals run online; Redis/BullMQ queues are verified in Docker and CI.

Operations Desk
Create a request, approve it as a manager and inspect the history with named participants. Switch organization to check that its records stay separate.
Open the example
Recorded real interface · test data · English UI

02 / DEVELOPMENT AND REPAIR

Good software can work better.

A missing feature, an awkward import or a bug that keeps returning. I can start with a specific change to the application you already use.

What I can buildA new feature or fix, regression tests and instructions for handing over the change.

An example to explore

Atomic CRM extension

Explore CSV review before writing: a preview, duplicates, invalid rows and explicit contact selection.

Explore the extension →Discuss a similar task →
Code and tests ↗A Java bug-fix example ↗

Atomic CRM is by Marmelab. My contribution: a contact-import review step. Available to run locally.

Atomic CRM extension
Explore CSV review before writing: a preview, duplicates, invalid rows and explicit contact selection.
Explore the extension
Recorded real interface · test data · English UI

03 / INTEGRATION AND AUTOMATION

Stop moving the same data twice.

An order arrives in one system and gets retyped into another. An update disappears after a failure, or arrives twice.

What I can buildA data flow with mapping, error handling and a way to verify what reached its destination.

An example to explore

Data Bridge + webhook reliability

Try a controlled flow with retries. Inspect a separate FastAPI and PostgreSQL implementation on GitHub.

Open the example →Discuss a similar task →
Code and tests ↗Explore integration tests too →
Data Bridge + webhook reliability

One event. One result.

  1. Receive the event
  2. Check for duplicates
  3. Deliver or retry

Inspect what happens after a lost connection and when the same record arrives again.

Open the example
Illustrated example flow · synthetic data

04 / MIGRATION AND REPORTING

Change systems. Keep track of your data.

You are moving records, combining exports or explaining different report totals. You need to know what matches and what needs correcting.

What I can buildA validated import, a discrepancy report and a trace back to the source of each issue.

An example to explore

Data migration / Revenue BI

Correct a mapping, replay rejected records and compare source with target. Explore where report values come from too.

Open the example →Discuss a similar task →
Code and tests ↗Reports do not match? Explore the differences →
Data migrationSource → match
6Source records
4Delivered before correction
6Matched after replay

TX-104 + TX-106Replayed after correction

SKU-X99 mapping corrected. Four delivered records remain unchanged.

Matching total: PLN 1,534.50

Open working example
Illustrated scenario · synthetic data · not a live run

05 / TEXT PROCESSING AND AI

Less reading. More usable information.

The same information needs extracting from requests and documents. Automation is useful when you can verify the result and catch mistakes.

What I can buildAn extraction workflow with validation, source references and review of uncertain results.

An example to explore

AI workflow lab + change evaluation

Follow a request through fields and sources. Explore a tool that catches regressions before release.

Open the example →Discuss a similar task →
Code and tests ↗

The lab uses synthetic data and simulated actions. The repository demonstrates evaluation; recorded model runs failed acceptance.

AI workflow lab + change evaluation

From a message to a checked result.

  1. Written request
  2. Fields and sources
  3. Human review

A result to review, with sources and visible errors.

Open the example
Illustrated example flow · synthetic data

Your situation is different?

Describe it in your own words. You do not need a ready-made solution or a specification.

Describe your situation →
All projects on GitHub ↗

Workflow demonstrations

Membership, booking and a reviewable handover

Try the new Operations Desk modules in a separate public test environment with its own database. Free hosting limits apply; this is a synthetic demonstration.

Synthetic data only. Payment simulator; no real bank, card or email connection. Discuss a complete application or start with one import, resource type or restore rehearsal.

03 / A clear starting point

How I start a project

  1. Describe the problem

    Tell me what happens today and what you would like to improve.

  2. I review the task

    I check the available materials, clarify open questions and identify what is needed to start.

  3. I suggest a practical next step

    I agree with you on the first stage, its result, price and timing before paid work. Further stages can extend the application.

  4. I build, test and hand over

    I show progress, check the result against the agreed requirements and hand over the code with setup instructions.

The initial review checks fit and the next step. A detailed audit, architecture or prototype is a separate agreed scope.

Portrait of Ivan Matiushkin
Ivan Matiushkin Poland / remote

04 / Independent specialist

Work directly with me

I am Ivan Matiushkin, an independent specialist in Poland working remotely. I build custom software, internal tools and automations for specific business problems. You work directly with me, from written requirements to handover.

Written-first collaboration

Independent contractor in Poland, working remotely. I can start by email with a written brief and an agreed paid test task. Working hours and any prepared calls are agreed separately. Settlement through Useme where compatible with the client; Useme is not my company.

Agreements and payment

I agree with you on scope, price, timing, ownership and support before work begins. Contracts and payments can be handled through Useme where applicable; Useme is an intermediary, not my company.

Technical examples and practical guidesExplore the automation demonstration →
Problems, checks and a sample deliverable

05 / Start with a description

What’s not working the way it should?

Two or three sentences are enough: which systems you use, what is not working and what result you need. No finished specification or phone call required. I will reply by email with questions or a proposed first scope.

You can also email me directly: ivan@matiushkin.com

LinkedIn · GitHub

I will use your details only to respond to your enquiry and discuss working together. Do not include passwords, customer data or other confidential information. Cloudflare delivers the message to my inbox, which is hosted by Google Workspace.

About your data and site statistics

Start with a description — no attachments or system access needed. Price and timing require a separate agreement.

Optional details
Useful details
  • What is manual or not working today?
  • Which systems do you use?
  • What specific result would help?

You do not need every answer. Start with what you already know.

How did you find me? (optional)

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