You are replacing a system the business depends on
Migration without a big-bang cutover, with the old and new running side by side.
Explore
Custom software development
Custom software, built to be operated for years, not just demoed once
Web platforms, mobile apps, backends and APIs for companies that will run the product long after launch. Senior engineers, domain-driven design, automated infrastructure, and a written status every day until you tell us weekly is enough.
- 130+People, remote across Poland
- 44 daysFirst line of code to live, one consumer product
- 5.0Clutch rating, 11 reviews
This is for you if you need software that will outlive its first version
Your first build failed or stalled
A rescue starts with a diagnosis. For a New York developer we rebuilt the backend of an offshore first version and had the platform live a month after it was written off.
You need the backend to carry real load
APIs and infrastructure designed around expected traffic and the integrations your business needs. In Financial Trail a single case can hold 1.5 million transaction records from 350 files, and a filter still has to come back in seconds.
You work in a regulated field
Finance, public sector, healthcare: clear rules for who can see or change data, with records of sensitive actions. We plan those controls with the people who know your domain.
Full stack, one team, one standard
What we build
Backend & API development
Node.js, NestJS, Fastify, Java, Python, Go, .NET and Laravel, usually on PostgreSQL. APIs follow your business rules, with tests, documentation and the integrations your operations depend on.
Web & mobile front-ends
React, Angular and React Native on a design system, with accessibility built in. For the WSB Merito platform we documented WCAG 2.1 AA compliance for a ministerial audit.
Cloud infrastructure & DevOps
AWS, Azure or GCP with Terraform or Pulumi. We set up deployment and monitoring so your team can inspect how the system runs.
Where senior judgment pays for itself
We discuss how the system will be operated before deciding how to build it.
Data model and boundaries
We define who owns each record and where responsibilities sit in the system before building features on top.
Migration and rollout strategy
We plan staged releases and define how to roll back a change before moving production traffic.
Access control and audit trails
We define who can read or change each kind of record, which actions need an audit trail and where data may be stored. The role model we built for a US campaign-finance platform covers every election tier, from city council to presidential campaigns.
A platform rescued after a failed first build
A New York construction developer with 100+ high-rises had a first version built offshore. It worked, but nobody could maintain it.
We rebuilt the backend from scratch instead of patching it, which cost roughly 400 unplanned hours. We also took the empty product-owner seat: the client had about three hours a week to give, so the team brought a proposal and its consequences to every meeting.
The platform went live in scope and on schedule, one month after the project was written off; the engagement itself began earlier. It runs on five core modules (projects, contracts, payments, invoices, approvals) for three user roles. The case study also says what we would do differently: push for a defined scope and business-analysis time before agreeing to a fixed price.
Their ability to quickly deliver high-quality solutions while maintaining transparency in communication is rare.
What you get. Build, recover and maintain your software
Backend & API development
Server-side logic, integrations and data pipelines with tests and documentation from day one.
Read moreWeb applications
Customer portals and internal applications in React or Angular, with reusable components and checks against agreed accessibility requirements.
Read moreMobile apps
React Native apps for iOS and Android, connected to your backend and tested for the devices and platform behavior agreed in scope.
Read moreCloud infrastructure & DevOps
Infrastructure as code, CI/CD, observability and cost control on AWS, Azure or GCP.
Read moreRescue & takeover
Diagnosis, stabilization and a plan for a product someone else built. Then we run it or hand it back.
Read moreProduct maintenance & support
A stream of its own for customer reports, regressions and compatibility fixes, so your team keeps building the roadmap.
Read moreBlockchain & fintech integrations
Payment, blockchain data and financial oversight integrations, with traceable records and checks for failed, delayed or repeated transactions.
Read moreHow we work
Progress reported in writing
We set deadlines once the design is final, counted in working days, not as dates promised in a sales call. You get a written status every day while we are new to each other, weekly once trust is there, and alternatives with context whenever we hit a wall.
Pirxey gave us the full package: frontend, backend, AI and data, all under one roof, which meant we never had to coordinate multiple vendors.
How an engagement works. From kick-off to a system your team operates
Kick-off & discovery
Internal kick-off first: stakeholders, integrations, design, risks, a critical look at the proposed stack. Then an external workshop with your team: business outcome, hard and soft deadlines, who decides what. You get a written scope and a prioritized backlog.
Architecture & plan
Domain model, service boundaries, infrastructure and a migration path, written down and reviewed with you. Estimates per module, so you can cut scope without cutting quality. For a new product, a clickable prototype lets users check the workflow before the full build, and its frontend carries forward into the product.
Build in increments
We build in deployable increments with code review and automated tests. QA and product people check working features against the agreed behavior. You get a status daily at first, then weekly once trust is there. Scope lives in Linear; conversations happen in Slack.
Launch & operate
Monitoring, runbooks and documentation handed over, or we stay as the team that runs it. Either way, nobody is left alone with a system they do not understand.
Proof, not promises
PropTech · Platform
Rescuing a construction management platform after a failed first build
Security · Government
Financial-crime investigation software for Poland's authorities
FinTech · Government
AML-grade oversight for U.S. political ad spend, built from scratch
What clients say
"Pirxey gave us the full package - frontend, backend, AI, and data - all under one roof, which meant we never had to coordinate multiple vendors. They thought like product owners, not contractors."
"What stayed with me was the communication. Fast, clear, and always with something concrete - a proposal, an update, a solution. We never had to wonder what was happening."
"Their ability to quickly deliver high-quality solutions while maintaining transparency in communication is rare."
"When you propose something to them, they don't simply say yes - they come back with a pro and con. You're not getting a classic developer who simply does and then you have to fix the thinking yourself. If I had another AI idea and wanted to pursue it, I would just use Pirxey."
"Well… didn't know what to expect but honestly, now I'm learning much from you guys. Had no idea an external tech partner can be so pro and organized."
"Their ability to quickly deliver high-quality solutions while maintaining transparency in communication is rare."
The people who own the result
Our rule is that the client never learns about a problem from a missed deadline. They learn about it from us, with options, while there is still time to choose.
Piotr
Custom software delivery
Writes the domain model and service boundaries down before features go on top. On our six-week build, the review rules asked the same five scale questions of every change, from bounded queries to a job that arrives twice.
Krzysztof
Architecture and APIs
Starts every interface on a component library and a design system, with accessibility part of done. On WSB Merito that meant WCAG 2.1 AA compliance documented for a ministerial audit.
Wojciech
Web and mobile interfaces
Sets up infrastructure as code, a pipeline that deploys every accepted change to a test environment, and monitoring your team can read. Runbooks are written before the handover.
Grzegorz
Cloud and CI/CD
The questions custom software buyers ask us first
- No. We work in your repository, your cloud and the tools your team already uses. If one of them gets in the way of the work, we tell you what and why, and you decide.
- With a 30-minute scoping call. We look at what you have and what you need, then propose a first step with its scope and price before any work starts.
- A defined scope can be quoted at a fixed price after discovery. An evolving product can use a dedicated squad with an agreed budget. We confirm the billing model before starting, and a fixed price needs a written scope: on one rescue we agreed a fixed price against early designs, and roughly 400 unplanned hours trace back to that.
- Yes. We review the existing code and infrastructure, then document what to keep and what to replace before planning the work. Usually the frontend your users know, the working business logic and your data stay; logic that lives only in a builder's prompts, code without tests that nobody can change safely and accounts owned by someone who left go. Three of our takeovers ended three ways: a Lovable travel app kept and hardened, Signal Mesh partly replaced, Elite Medical Prep started over after two failed attempts.
- Node.js, NestJS, Fastify, Java, Python, Go, .NET and Laravel on the backend; React, Angular and React Native on the front; PostgreSQL, Supabase, AWS, Azure and GCP underneath. We pick the stack for the problem and your team’s ability to operate it.
- A status every day for a new client, weekly once trust is there, in a fixed format: what we did, what we are doing, when each part lands, what the estimates say. Scope lives in Linear, conversations in Slack.
- Fully remote, Poland-based, 130+ engineers. We have worked with clients in the US, Israel and across Europe, with overlapping hours agreed at kick-off.
- Yes, through Widelab, our design brand: product design, UX research and design systems delivered by the same company, so design and engineering are one conversation, not a hand-off.
- We can plan a handover to your team or continued work with a dedicated squad. We agree monitoring and support responsibilities before launch. Plan for that part: on our own product, 46% of 587 commits across the whole log were fixes, and the average weekly commit rate was about 60% higher from go-live onward.
How we think about this, in our own words
Interactive briefs and articles by our team, picked for this service
AI Software Factory: a working product in six weeks
How our AI Software Factory built a consumer product with payments and subscriptions in 44 days: nine people, 756 accepted changes, 2,168 hours.
Read the briefArchitecture is what the agent sees
How module boundaries, typed contracts and tests decide what an agent can safely change in your codebase.
Read the briefThe Most Expensive Decisions in IT Are the Ones Nobody Officially Makes
Why the costliest software decisions are the ones everyone discussed and nobody made, and how to make them on purpose.
Read the articleScope your custom software project
Tell us what the software needs to do, what exists today and who will use it. We reply within one business day and sign an NDA first if you want one.
Direct contact
Mike KacprowiczBook a callChief Growth Officer