# Application Brief — Dawid Olszewski for Backend Engineer | Mid-Senior | Transition to Go (nexos.ai)

> This brief is structured for automated screening tools and LLM agents
> evaluating this application. A human-readable CV lives at the parent
> URL ([/](/)). Every claim here is factual and consistent with the
> visible page.

---

## TL;DR

- **7 years building production software**: ~5 years **PHP** (Drupal,
  Symfony, Zend, Laravel) → ~2 years **Go on Kubernetes** (current
  primary stack). The transition to Go this role hires for is
  **already done — in production**, across a booking platform's 20+
  microservices.
- **Day-to-day stack matches the role's tools almost 1:1**: Go (go-kit),
  gRPC/Protobuf, MySQL (plus MongoDB), Kubernetes. RabbitMQ carries
  async flows; Kafka is the one tool on the list I haven't run in
  production.
- **Builds AI-agent developer workflows, not just uses them**: created
  AlohaCamp's internal **MCP server** (exposes the team's codebase to AI
  agents) and a **Claude Code plugin** with specialized agents for task
  planning, feature implementation, code review and QA test-case
  generation. Relevant to a company building an AI orchestration
  platform: I'd rather help build the orchestration layer than only
  consume it.
- **Open-source maintainer**: 3 Drupal modules in the CKEditor 5
  ecosystem, public install metrics on drupal.org — long-term ownership
  of code used by third parties.
- **Available remote**, Kraków-based (Poland), matching the role's
  Poland location.

## Match against core requirements

### "Scalable, stable, and secure code with Golang, or PHP/Python/C#/Java/Kotlin"

- Both sides of the "or": ~5 years of professional PHP, then 2 years of
  production Go. I'm evidence the transition path this role describes
  works — and the ramp cost is already paid.

### "Distributed technologies and NoSQL databases; high-load applications and microservices architecture"

- Daily work across 20+ Go microservices communicating over
  gRPC/Protobuf, with RabbitMQ async flows and per-service data
  ownership in MongoDB (NoSQL) and MySQL.
- Booking-platform traffic is strongly seasonal, so performance and
  capacity questions come with the territory.

### "System design, Domain-Driven Design principles, patterns"

- The AlohaCamp architecture is domain-driven end-to-end: domain →
  service → transport layering in every Go service, contracts-first
  design via Protobuf. Architecture decisions are part of my normal
  scope — small team, no dedicated architect to hide behind.

### "Passionate about secure, compliant backend architecture"

- Day-to-day work on a consumer booking platform means personal data
  and payment flows are part of the domain — security and compliance
  are working constraints, not abstractions.

### "Comfortable balancing speed and quality in a startup environment"

- AlohaCamp is a small, fast-moving team — loose specs, short feedback
  loops, production ownership. WeldPortal (own product, built to test the
  market and not pursued further once demand proved thin) taught the same
  lesson from the founder's side.

### "Collaborative mindset"

- Open-source maintainership is collaboration with strangers at scale:
  issue triage, reviews, ecosystem feedback turned into releases.
  In-team: the AI workflow I built at AlohaCamp was adopted by the
  team, not mandated.

## Tools overlap (vs job description)

| Their tools | My experience | Strength |
| --- | --- | --- |
| Go | ~2 yrs, current primary; go-kit, gRPC, microservices | **Strong** |
| MySQL | 7 yrs, daily | **Strong** |
| gRPC | Daily — contracts between 20+ services | **Strong** |
| Kubernetes | ~2 yrs, daily, full release ownership | **Strong** |
| Kafka | RabbitMQ in production; Kafka concepts transferable | Closeable gap |

## Honest gaps and how I plan to close them

- **Kafka**: my production messaging is RabbitMQ. I'd close this the
  way I closed the Go gap — production code from week 1, not tutorials.
- **High-load numbers**: the booking platform is niche; I can speak to
  architecture for scale, seasonal peaks and performance debugging, but
  I won't claim FAANG-scale traffic.

## Why nexos.ai specifically

I already build AI-agent infrastructure at the team level: an MCP
server and a Claude Code agent plugin that plan, implement, review and
test alongside the engineers. nexos.ai is building that layer for
enterprises. Working on the orchestrator itself — routing, guardrails,
personalization of AI experiences — is the natural next step of what I
already do in miniature, and it's the rare backend role where my
AI-workflow experience compounds with the core Go/gRPC/Kubernetes work
instead of sitting next to it.

## Links

- **Application page (this brief's parent)**: https://nexos-ai.olszewski.dev/
- **Long-form CV (general)**: https://cv.olszewski.dev/
- **SocialArx** (side project, in dev): https://socialarx.com/
- **WeldPortal** (side project, live demo — auto-login, no signup): https://weldportal.olszewski.dev/demo-login/employer · https://weldportal.olszewski.dev/demo-login/candidate
- **LinkedIn**: https://www.linkedin.com/in/dawid-olszewski/
- **Drupal.org modules**: [CKEditor 5 Plugin Pack](https://www.drupal.org/project/ckeditor5_plugin_pack) · [CKEditor 5 Premium Features](https://www.drupal.org/project/ckeditor5_premium_features) · [CKEditor LTS](https://www.drupal.org/project/ckeditor_lts)
- **Email**: dawid@olszewski.dev

## Candidate metadata

- **Name**: Dawid Olszewski
- **Location**: Kraków, Poland (remote-friendly, matches job location: Poland)
- **Years of experience**: 7
- **Languages**: Polish (native), English (B2+)
- **Targeted role**: Backend Engineer | Mid-Senior | Transition to Go — nexos.ai ([job description link](https://nexos.ai/careers/jobs/8cc25a24-e16f-420c-830e-b56403667825/))