codechu.

Independent software systems engineering

Complex software
problems.
Solved.

When a software problem keeps returning and the cause isn’t clear, start here.

Get a clear diagnosis and, when needed, hands-on implementation. Architecture, performance, SQL/data, and distributed systems.

Discuss a problem Explore engagements

Independent senior engineer. Work directly with Onur.

Deep in the backend.
Across the whole system.

  • C# / .NET
  • Architecture
  • Distributed systems
  • SQL Server
  • Performance

01 / When to bring me in

The problem that keeps
coming back.

Bring me in when your team needs a clear diagnosis, an architectural decision, or a safe modernization path.

Something is slow. The reason isn’t clear.

The database is under pressure, responses are slow, or services behave unpredictably.

The architecture is getting in the way.

Changes feel risky. Integrations are brittle. The issue crosses service boundaries.

The old system still has a job to do.

Modernize legacy systems in stages while keeping them useful.

02 / Focused engagements

A focused scope.
A practical next step.

Start with an investigation.
Implement when the path is clear.

ENGAGEMENT / 01

Architecture &
Performance Diagnostic

Start with an unclear problem. Get a focused investigation and a recommended next step.

  • Architecture and code investigation
  • Bottlenecks, risks, and prioritized findings
  • Written report with a recommended solution path

A standalone engagementDiagnosis first.

Discuss a diagnostic
ENGAGEMENT / 02

Legacy .NET
Modernization Assessment

Modernize legacy .NET in stages, keeping what still works.

  • Current state, dependencies, and migration risks
  • Architectural recommendations
  • Staged migration plan and implementation roadmap

A route for your existing systemA staged plan.

Discuss modernization
ENGAGEMENT / 03

Focused
Engineering Sprint

Hands-on implementation for a defined software-system problem.

  • Performance bottlenecks and backend defects
  • Architecture refactoring and migration
  • Messaging, integrations, and distributed systems

A defined technical problemWorking solution.

Discuss a sprint

Scope, deliverables, and price agreed after a short technical discussion. Implementation can follow as a separate engagement.

03 / Selected engineering work

Different systems.
The same curiosity.

Anonymized examples from .NET,
distributed systems, and data processing.

01

DISTRIBUTED SYSTEMS / DAPR

Working through system limits

Problem
A Dapr limit issue required correction.
Approach
Investigate the limit and the system’s behavior.
Solution direction
A targeted correction to the Dapr issue.
02

DATA PROCESSING / PLM

Breaking the problem into chunks

Problem
A data-processing problem in a PLM system.
Approach
Divide the processing work into manageable chunks.
Solution direction
A chunking-oriented solution.
03

MODERNIZATION / T-SQL → .NET

Moving logic beyond the database

Problem
Existing T-SQL logic needed modernization.
Approach
Review the logic’s place in the backend architecture.
Solution direction
Migration toward modern .NET.

Brief problem patterns, without outcome or performance claims.

04 / The engineer behind Codechu

Onur Barlık.

Independent engineer.
Systems thinker.
Problem solver.

WRITING SOFTWARE SINCE1997

I want to understand why a system behaves the way it does. Then help it behave better.

My work centers on backend and distributed systems, with deep C# / .NET experience. I’m drawn to ambiguous problems: unexpected behavior, difficult migrations, and architecture decisions without an obvious answer.

Codechu is my independent practice. You work directly with me, from investigation through implementation.

Tools follow the problem.

C# / .NET, SQL Server, Redis, RabbitMQ, Dapr, NATS, Docker, and Kubernetes. I choose the tools to fit the system and the problem.

05 / How we work

Less ceremony.
More clarity.

A technical conversation.
A focused scope and a clear handover.

  1. 01

    Describe the problem

    Share the symptoms, system context, and what you’ve already tried.

  2. 02

    Talk it through

    A short technical conversation to understand the situation and fit.

  3. 03

    Define the scope

    Agree the scope, deliverables, access, and price before starting.

  4. 04

    Follow the evidence

    Investigate or implement, with clear updates along the way.

  5. 05

    Hand over clearly

    Findings or a working solution, with a clear handover.

Let’s find the right next step

A difficult problem
is a good place to start.

You don’t need a perfect brief. Start with what’s happening.

Email Onur

onur@codechu.com

Describe the problem directly to Onur. No project commitment.