Skip to content
Marcin Adamczyk

Senior Software Engineer · Independent Technical Partner

Need to move faster?I’ll build the next part.

I help founders and product teams turn unclear requirements, fragile systems and difficult integrations into shipped software.

One senior engineer. Direct access. From first look to shipped code.

Product features · Existing systems · Integrations · AI-assisted development

When to bring me in

When the next move needs more than more code.

Bring me in when the technical path or scope is not yet clear enough to act on.

01

The feature is still unclear

I turn product intent, constraints and edge cases into a buildable technical plan. I make assumptions explicit before they become code.

Idea → plan

02

The system works, but the next change feels risky

I understand the existing code, limit the risk and implement the change without forcing a rewrite. The approach fits the codebase and its release path.

Risk → shipped change

03

The difficult part needs senior ownership

Integrations, backend workflows, data flow or AI-assisted code that needs proper engineering review. I stay responsible for the technical choices and what ships.

Draft → dependable software

Explore services

Ways to work together

Start with the level of ownership you need.

The engagement stays close to the work: a focused review, a defined build, or ongoing senior support.

01

Review

A senior technical review of a repository, feature, integration, or decision.

Result: Risks, decisions, and a practical next step.

02

Build

I design and implement the feature, integration, or backend change.

Result: Working, reviewed software.

03

Ongoing

Fractional senior engineering support for decisions, implementation, and code review.

Result: Senior ownership without another full-time hire.

See how I work

Why work with me

You work directly with the engineer making the decisions and writing the code.

I’m a senior software engineer with over 13 years of experience across startups and larger companies. My strongest areas are Ruby on Rails, backend systems, integrations, system design and product delivery.

  • Ruby on Rails
  • Backend systems
  • Integrations
  • System design
  • Product delivery
  • AI-enabled workflows
More about me

Start here

Bring me the difficult part.

A repository, Loom, rough feature brief or a few honest sentences are enough. I’ll tell you whether I can help and what the next useful step is.

No polished brief needed.