IT WORKS. BARELY. WE FIND WHAT'S HIDING.
That "temporary" fix from 2021 is now load-bearing. The consultant who drew impressive diagrams vanished when problems got hard.
We assess. We embed with your team. We leave them stronger.
For CTOs, VPs of Engineering, and technical leaders at growth-stage companies.
"We hired Szymon twice. The platform he built handles 10x what the old one could. It's the core of our business now."
— CEO, Hospitality Payments PlatformProblems We Solve
The monolith that grew too fast. The microservices that became a distributed nightmare. The compliance audit three months out. The on-call rotation burning out your best people. We've seen these patterns before.
System Architecture
Systems designed for the scale you need in 2-3 years: multi-region deployments, event-driven processing, cloud-native patterns proven inside Tier-1 banks.
Fintech, Payments & Travel
Over a decade building systems where failure costs real money. Payment gateways, trading platforms, and travel tech. We know the regulatory constraints and the operational pressure.
Embedded Senior Engineering
The people in the sales call are the people doing the work. Senior engineers embedded with your team. We pair, build, and transfer skills until your engineers own the systems independently.
Technical Leadership
Fractional CTO and strategic technical leadership. Setting direction, building the right team, and making sure the board speaks engineering.
We also specialize in
Engagements We've Delivered
Real pressure, real deadlines. Systems that couldn't go down. Teams that needed to ship faster. Here's what we delivered, and what it took.
Multi-Region Payment Gateway
Engineered payment gateway microservices with multi-region availability. Built Kafka-based event-driven architecture for asynchronous payment monitoring and reconciliation across three AWS regions.
Platform scaled to handle 1M+ daily transactions, supporting revenue growth without adding operational headcount.
10x Scale During Hypergrowth
Led architecture decisions for a hospitality payments platform during rapid expansion. Redesigned core systems and migrated to managed cloud services, cutting infrastructure costs by 40%. Introduced TDD practices and modernized legacy Groovy codebase to Kotlin.
Supported 10x revenue growth while cutting infrastructure costs by 40%. The platform became the core of the business.
AI Assistant Shipped to 50,000 Employees in 12 Weeks
The bank needed an AI productivity tool across 50,000 employees within one quarter, a board-mandated deadline. We embedded with the team, built the Kotlin/Spring Boot backend, integrated LLM models with enterprise workflows, and ran comprehensive load testing. Shipped to production on time for the bank-wide rollout.
Met a board-mandated deadline. Shipped to 50,000 employees in 12 weeks, now adopted enterprise-wide.
Global Airline Reservations Platform
Built airline reservations service handling sensitive PII and payment data with enterprise-grade encryption and compliance controls. Led development team to become highest-performing unit within the global program. Designed scalable service frameworks adopted across multiple teams.
Team went from middle-of-the-pack to #1 velocity. Service framework adopted programme-wide, accelerating delivery across 20+ teams.
Legacy Batch Processing: 1 Hour to 45 Seconds
Modernized a healthcare billing reconciliation system nobody would touch. No tests, no documentation, no original builders. Used inverted TDD to capture existing behavior as a spec, then rewrote incrementally with parallel validation.
System that blocked releases for months became a non-issue. 80x faster processing, two junior engineers now own it independently.
"We hired Szymon twice. The first time he modernized our codebase and introduced real engineering practices. The second time we handed him the keys to rearchitect everything. The platform he built handles 10x what the old one could, and it's the core of our business now.
"We almost bought a third-party monitoring tool we didn't need. Szymon did the analysis, showed us our in-house system could do more, and made it happen. That saved us a vendor dependency and a six-figure contract. He thinks like an owner, not a contractor.
"Szymon built the reference architecture templates that twenty other teams ended up adopting. He didn't just ship his own service — he turned what he built into the golden path for the entire programme. His team went from middle-of-the-pack to the highest-performing unit in the delivery.
Ready to talk?
30 minutes. No pitch. Just a conversation.
How We Work
We assess. We chase it down alongside your team. We unleash them. Three phases, each with named checkpoints — so you always know where we are and what comes next.
The Pointer Assessment
2–3 weeksFive trails through your engineering health. We find what's hiding before it bites.
The Chase
3–12 monthsEmbedded engineering alongside your team. Building, fixing, shipping.
The Unleashing
4–8 weeksYour team operates independently. Proven, not assumed.
Who You're Working With
Szymon Kaczorowski
I've spent 15 years inside systems that can't go down — payment gateways built for 99.99%+ uptime, monolith-to-microservices migrations at HSBC, architecture that took a fintech platform from first users to 10x scale. Every engagement taught me the same lesson: the teams that succeed aren't the ones with the best architecture. They're the ones who understand their own systems well enough to own them.
That's why I built Grupa VII around the methodology you see above. The Pointer Assessment came from years of walking into codebases where nobody could tell me what would break first. The Chase came from JP Morgan, Sabre, and a dozen startups where the only way forward was to embed, pair, and ship alongside the team. The Unleashing came from the realization that if your team can't continue without me, I haven't done my job.
Recent Writing
Real problems, real codebases, real decisions. Technical deep-dives from engagements and the patterns we keep seeing.
Deep Tracks: Mapping India Outside the Heap
When your dataset is 33 billion grid squares and your deployment constraint is one machine, the JVM's garbage collector becomes your enemy. How memory-mapped files turned an impossible memory problem into a solved one.
The Overgrown Trail
A healthcare financial system's batch processing took an hour. After the rewrite, it took 45 seconds. But the 80x speedup wasn't the real win was removing the production risks that had accumulated over years of neglect.
Picking Up the Scent
A CTO asked for an honest assessment of their stack before a board presentation. What I found in two days changed how she talked about engineering to her board, and probably saved the company from a painful surprise during their next fundraise.
Frequently Asked
Answers to the questions we hear most often. If yours isn't here, let's talk.
We embed with your team for 6-24 month engagements. Not as outside observers. We push to your repo, attend your standups, join your Slack channels, do code reviews, participate in architecture discussions, and share on-call rotations. When we leave, your team should be stronger than when we arrived.
We start with a 3-month initial engagement, enough time to assess, embed, and deliver measurable progress. Most clients continue for 6-24 months as we move through the full methodology, but either party can end with 30 days notice after the initial period. We earn continued business; we don't lock you in.
Assessments and due diligence are fixed-price: defined scope, clear deliverable, number upfront. Embedded engineering is a monthly retainer scaled to team size and involvement. Fractional CTO engagements are monthly at a lighter cadence. We're upfront about costs before any work begins. No surprises, no padding. The best way to get a number is to scope it together.
No. After the 3-month initial engagement, we continue month-to-month. There are no lock-in contracts or cancellation penalties. Most clients stay because the work is delivering value, not because they're contractually obligated.
Fintech, banking, payments, and travel. Industries where I've spent over a decade building systems that process real money and serve millions of users. I understand the regulatory constraints, security requirements, and operational pressures.
NDAs before any technical discussions. All code belongs to you. We don't reuse client code across engagements. We follow your security policies.
With your team, never instead of them. We mentor, pair program, and transfer knowledge. Your team should be better engineers after working with us.
We stay on problems until they're solved. We don't hand off to junior developers after the sale. We limit our client count so you get focused attention. And we measure success by whether your team can continue without us.
Engagements are led by a principal-level engineer with over a decade of experience. Team size is typically 1-3 senior engineers depending on scope. We don't subcontract to juniors. The people in the sales call are the people doing the work.
We're based in Poland (CET/CEST) and have deep experience working with distributed teams across Europe and the US. We maintain significant overlap with both London and US East Coast hours, and adjust our schedule to match your team's core hours.
Typical ramp-up is 1-2 weeks from contract signing to first commit. We spend the first week on codebase orientation, meeting the team, and understanding your architecture. By week two we're contributing to code reviews and sprint work. Full productivity within the first month.
Our Stack
Languages
Frameworks
Cloud
Data
Practices
Start the Conversation
30 minutes. No pitch. Just a conversation to see if we're the right fit, with honest feedback even if we're not.
You'll speak directly with Szymon. Video call, no salespeople, no prep required.