Load does not break systems.Decisions made two years earlier do.

one/2/work builds the parts that carry weight: backends under load, apps on every screen, and AI that runs in production with a budget, an evaluation set and someone on call. A team of 50+, for products that cannot afford a bad Tuesday.

What we don't do
  • Websites
  • Landing pages
  • MVPs for a pitch deck
  • Bodies by the hour without a brief
  • Demos that never ship

01

What we build

Three kinds of work. Each has a failure mode we have seen often enough to name it.

01

Backends under load

Products where the load graph only goes up

What usually breaks
One database, synchronous writes, a rollback nobody has rehearsed
What we build instead
Event-driven core, idempotent writes, capacity proven on a rig before the season proves it for you
Team and time
5–8 people · 4–6 months
GoJavaKafkaNATSPostgreSQLClickHouse

02

Apps on every screen

Teams shipping to phone, desktop and watch at once

What usually breaks
Two codebases, manual regression, one release a quarter
What we build instead
Shared Kotlin core, native UI where the platform expects it, automated regression, a train every two weeks
Team and time
3–5 people · 3–5 months to store
SwiftSwiftUIKotlinComposeKMPC#WinUI

03

AI in production

Companies whose AI pilot impressed everyone and never shipped, and companies that need to add AI to a system already under load

What usually breaks
No evaluation set, no cost ceiling, no fallback for when the model is wrong, and a demo that dies on the first real data
What we build instead
Retrieval over your own data, agents with human checkpoints, evals gating every release, self-hosted inference when the API bill stops making sense, and an on-call rotation for the model like for any other service
Team and time
2–4 people · 8–12 weeks to the first production slice
PythonPyTorchvLLMTritonpgvectorQdrantRAGMCPLangGraph

02

One engagement, week by week

How a typical project runs, from the first letter to the day we hand over the pager.

  1. Week 0

    You describe the system. We read it.

    Not a sales call. A written first read of your system within three business days, with the questions we would bring to a call.

    You hold: a first opinion, in writing

  2. Weeks 1–2

    Audit sprint

    We read the code, the incidents and the graphs, and talk to whoever gets paged. Two people, fixed price, your repository.

    You hold: a plan, ranked risks and a price

  3. Week 3

    First increment on your staging

    Every two weeks something demonstrably works, demoed live, with hours reported against the plan.

    You hold: working code and a burn chart

  4. Week 8

    We break it first

    Load rig at twice the forecast peak, failure drills, a rollback someone has actually performed. Launch day is boring on purpose.

    You hold: a load report and a runbook

  5. Week 14

    Launch

    Staged rollout behind flags. The same team that built it is on call for it.

    You hold: a system that survives a Tuesday

  6. Week 15+

    Stay or step back

    We keep the pager, or we train your team and leave the runbooks behind. Leaving us takes a calendar invite, not a migration.

    You hold: everything, in your repository

Weeks are indicative. The order is not.

03

Rules of engagement

No bench, no subcontractors. The rules below are why clients stay.

50+ people, four practices

Backend and platform
22
Mobile and desktop
12
Data and AI
10
SRE, QA, design
8
  1. 01

    You meet the team before the contract.

    If you would not hire them, we do not staff them.

  2. 02

    Nobody is rotated off mid-project.

    Whoever designed the system is still there when it is time to scale it.

  3. 03

    Every decision is written down, in your repository.

    Nothing lives in a chat thread.

  4. 04

    We say no before the contract, not during it.

    If the deadline or the budget does not fit the work, you hear it in week zero.

  5. 05

    The team that built it is on call for it.

    Incentives stay honest when the author is the one woken up.

  6. 06

    No account managers.

    You talk to the people doing the work. That is the whole layer.

  7. 07

    A model is a service, not a demo.

    It gets an SLO, a cost ceiling, an evaluation set and a pager, or it does not ship.

  8. 08

    After twelve months you may hire them.

    With a transfer fee agreed up front. Better that than pretending the option does not exist.

04

What it costs

Four ways to buy the same team. Prices are anchors; the number you sign comes out of the audit sprint.

Start here

€8k

fixed

Audit sprint

Two weeks, two people, your repository. A plan, ranked risks and a price. If any of the three disappoints you, it ends there and you keep the documents.

Fits when you need to know what you are dealing with

€8.6k

per person · month

Squad

Five to ten people owning a product line end to end, with a named lead. Monthly, thirty days' notice.

Fits when the work is a product, not a project

€95k

per phase

Project

A defined launch with a hard date. Phases with a fixed price each, once the audit sprint has told us what is inside.

Fits when there is a date and a scope

€54

per hour

Specialist

One to three named people inside your own team, on your rituals. Weekly timesheets.

Fits when you have a team and a gap

Every model includes a lead and QA without extra billing, a security review before each release, an NDA and a GDPR data-processing agreement, and full IP transfer on payment. Rates assume 160 billable hours a month.

05

The stack we answer for

Conservative on purpose: tools you can still hire for in two years. Anything unusual arrived with a written reason and an exit.

stack.txt
backend:
Go · Java · Kotlin · C# · .NET · C / C++ · Python · Node.js · Rust · Spring Boot · ASP.NET Core · gRPC · Protobuf 3 · GraphQL
web:
TypeScript · Vue.js · Nuxt · Next.js · React · Node.js · Vite · WebSocket · SSR
data:
PostgreSQL · MongoDB · ClickHouse · Elasticsearch · Redis · Kafka · NATS · NATS JetStream · RabbitMQ · Debezium · Airflow
infra:
Kubernetes · Helm · Docker · Terraform · ArgoCD · GitHub Actions · AWS · GCP · Bare metal · Prometheus · Grafana · OpenTelemetry
mobile:
iOS · iPadOS · watchOS · macOS · Windows 10/11 · Android · Linux · Swift · SwiftUI · Kotlin · Compose · KMP · C# · .NET · WinUI · Qt · Flutter
load:
k6 · Gatling · JMeter · Testcontainers · Playwright · pprof · Failure drills
ai:
PyTorch · vLLM · Triton · TensorRT · ONNX · Ray · RAG · MCP · pgvector · Qdrant · LangGraph · MLflow · Claude / OpenAI APIs

06

Objections we hear early

All answers open. Nothing behind a click.

You are in Serbia. Is that a problem for an EU company?

It is simple. OneTwoWork doo is an EU-compatible counterparty: contracts under your law or ours, invoices in EUR, VAT handled, a GDPR data-processing agreement signed with the MSA. CET hours cover the whole EU working day.

Will you take over code you did not write?

That is most of our work; the audit sprint exists for it. We have never walked away from a codebase, though we have twice recommended a rewrite the client did not want to hear about.

Do you work fixed price?

Per phase, yes, once the audit sprint has told us what is inside. Fixed price on an unexamined system is a guess dressed up as a commitment, and one of us always pays for it.

What if the load we plan for never arrives?

Then you paid for headroom you did not need. That is why the first phase is sized to the load you can actually forecast, and the rest stays a documented plan.

What happens when someone leaves the team?

Rarely, but it happens. Every part has two people who can carry it, decisions are written in your repository, and the handover period of a replacement is not billed.

Our AI pilot works. Why isn't it done?

Because a pilot answers one question and production answers thousands, some of them hostile. Between the two sit an evaluation set that tells you when the model got worse, a cost ceiling so a traffic spike does not become an invoice, a fallback for when the model is wrong, and someone who is paged when it is.

07

Describe your system

Tell us what it is and what is wrong with it. You get a written first read within three business days.

Before you write — a quick fit check

Write to us if

  • Your system has real load, or a date by which it will
  • Something is already in production, or there is code to read
  • You want a written opinion before a sales conversation
  • You can give us two weeks and access to the repository

Probably not us if

  • You need a website, a landing page or a small app
  • The budget is under €50k and the scope is still open
  • You want a quote without anyone looking at the system first
  • The decision is about price alone

If you are unsure which column you are in, write anyway. Saying no quickly is also a service, and we do it in writing.

NDA on request. Your data stays in the EU. We answer ourselves, with no automated sequences.

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