Professional profile
Przemysław Bańkowski
Senior Software Developer – .NET specialist
I build software that ships to production and actually solves the client's problem — from idea to deployment.
5+
years of commercial experience
21+
delivered projects
2×
Team Leader role
C2
English level
About
For over 5 years I've designed and built commercial applications — architecture, business logic, integrations, deployment. .NET/C# is my main specialization. I've also worked as a backend team leader, with real responsibility for code quality and the stability of systems running in production.
If your project needs a different stack than .NET, I've likely already worked with it — PHP on warehouse and ERP systems, Python on camera image analysis, Angular and React on frontend integrations, Qt and C++ on a mobile app. One project I built end-to-end, solo: backend in .NET, frontend in Next.js, smart contract in Rust.
Domains I've worked in:
ERP & finance
HR & time tracking
Asset management
Manufacturing & maintenance
Logistics & warehousing
Web3 / Blockchain
AI
Digital accessibility
Public sector & education
What I do
End-to-end project delivery
From requirements analysis through implementation to deployment — regardless of the technology stack.
Backend architecture in .NET/C#
From a single module to multi-module systems — DDD, Clean Architecture, production scale.
Integrations & process automation
Connecting external systems and orchestrating processes — AI APIs, blockchain, exchanges, client systems.
Team leadership
Coordinating a backend team's work, responsible for code quality and stability.
Spec Driven Development
Precise specification of requirements and architecture before implementation — especially when working with AI-native tools.
BACKEND
.NETC#ASP.NET CoreEntity Framework CoreDDDClean Architecture
DATA
SQL ServerMySQL
API
REST APISignalRJWTOAuth2
DEVOPS
DockerCI/CDAzureAzure DevOps
TESTS
xUnitTestcontainers
FRONTEND / OTHER
ReactNext.jsAngularRustPython
Selected projects
Web3 / Blockchain
Team Leader
Web3 platform for trading digital assets
A commercial Web3 platform for trading digital assets (NFTs), used in production by thousands of users. I was responsible for the .NET backend architecture, core business logic, and coordinating the backend team as Backend Team Leader.
↳ Led a 5-person backend team, platform serving thousands of active users in production
Context: a multi-module, enterprise-class platform for buying virtual real estate in the Metaverse (NFTs), architecture based on Domain-Driven Design with separate domain models for transactions, balances and assets — decoupled from blockchain and payment integrations.
Auction/marketplace engine: designed and built from scratch a trading system for NFT land plots — bidding auctions, fixed-price sales, bulk sales, full auction-state control → the core of the platform's transaction mechanism, handling real trading of thousands of NFT plots.
Database performance: the Cartesian Explosion problem when fetching one-to-many relations was overloading server memory and CPU. Solution: query splitting (
.AsSplitQuery()) and disabling change tracking on reads (.AsNoTracking()) → shorter API response times on read operations.Real-time data: SignalR (WebSockets) for instant updates of balances, asset prices and blockchain transaction statuses in the UI.
Metaverse map optimization: the "fetch the whole visible area every time" approach made the interactive map's first load take several seconds. Together with the frontend, I reduced the amount of data transferred and changed the fetch strategy (full area once, then only new fragments) → noticeably faster first load and smoother map panning.
Leadership role: coordinating a 5-person backend team, code review, mentoring, coding standards, close collaboration with the PM, smart-contract team, frontend and DevOps (CI/CD, Docker), Agile in Azure DevOps.
Web3 / Blockchain
Web3 platform for creating and managing utility tokens
My own Web3 "token launcher" project on Solana — from concept, through a .NET backend and a Rust smart contract, to a Next.js frontend. Ran in production with around 6,000 real users, including 800 within 3 days during a growth spike.
↳ ~6,000 real production users (800 in 3 days), solo from concept to deployment
Context: a personal project, built end-to-end as the sole developer — .NET 8 backend in Clean Architecture, a Rust/Anchor smart contract, Next.js/React frontend with Solana wallet integration.
On-chain/off-chain economics: computing full token allocations on-chain would be costly and inflexible. Solution: the backend calculates and signs the allocation with an Ed25519 key, the contract only verifies the signature before payout → lower transaction costs without losing flexibility in business rules.
"Earn-to-promote": designed and tested a reward mechanism, paid in the platform's token, for verified social-media promotion tasks, protected against farming with reCAPTCHA v3.
Controlled token sale: a contract with an explicit sale-round state (rising price), hard sale limits (per transaction, per round and globally), and an emergency-pause mechanism with a one-hour cooldown → predictable token distribution with no risk of overselling or pause-mechanism abuse.
Scale: around 6,000 real production users, including 800 within 3 days during a promotional campaign, dozens of tokens created.
Web3 / Blockchain
Team Leader Blockchain-based competition and media platform
An enterprise-class system for sharing media and running competitions with secure cryptocurrency prize transfers, built on public and private blockchain, with vote purchases integrated with Stripe.
Vote synchronization: a batched write mechanism (batch vote) and a dedicated scheduler with automatic retries of failed crypto transfers after on-chain errors → resilient to temporary blockchain-network failures, competition closing and prize distribution without manual intervention.
User-generated content control: only identity-verified (KYC) users could create their own community competitions, additionally approved by an administrator before launch → a controlled user-generated-content mechanism that preserves platform compliance and security.
Leadership role: coordinating the backend team, code review, mentoring, coding standards, Agile in Azure DevOps.
AI / Automation
Finance
Exchange trade automation and monitoring system
A proprietary trading bot run on my own capital, operating 24/7 in production on a VPS — assessed as profitable/promising on real capital.
Market anomaly detection: an algorithm detecting significant large orders in the order book — a statistical threshold (standard deviation), a USD liquidity threshold, a volume threshold and a round-price requirement — as a position-entry signal.
Risk management: early signal invalidation when the order shrinks below 30%, plus a Pearson correlation filter with BTC (above a set threshold → order cancellation), independent of the classic stop loss.
Position management: up to three progressive take-profit levels, a two-tier stop loss (primary + emergency) and a trailing stop-loss threshold that follows price movement — full automation of open-position management without manual intervention.
Duplicate-transaction protection: out-of-order WebSocket events and possible duplicates could lead to a trade being executed twice. Solution: a state machine + async semaphores (
SemaphoreSlim) → stable processing with no risk of double-spending. Manufacturing / infrastructure
PPM system for production performance monitoring
A system monitoring production-line performance, deployed at several manufacturing-sector clients, calculating the OEE (Overall Equipment Effectiveness) metric from machine data.
OEE loss engine (Loss Analyzer): automatic calculation and categorization of performance-loss causes on production lines based on configurable conditions → replacing manual analysis with an automated calculation.
Input data quality: when the OPC connection to a machine was lost, the system could incorrectly treat it as still running. Solution: automatically switch the machine's status to "Off" on connection loss → protecting OEE calculations from bad data.
Manufacturing / infrastructure
CMMS system for maintenance management
An application supporting machine oversight for several manufacturing-sector clients — inspection scheduling and repair cost accounting.
Digital inspection checklists: configurable questions and answers with photo attachments, linked to a specific task and machine → a structured, digital replacement for the paper inspection report.
Hall/Map editor: a visual layout of machines on the shop-floor plan instead of a text list → faster location of a machine needing inspection or repair.
Finance
HR
Manufacturing / infrastructure
ERP system for business process management
A large, mature ERP system integrating finance, HR and production, providing data centralization and automation of key workflows.
Finance & HR document workflow: business-partner registration, IBAN-standard bank account number validation, invoice generation and editing.
Production planning: assigning tasks to employees, reports summarizing work on production orders, a mechanism calculating completed output quotas, and Gantt chart editing.
Manufacturing / infrastructure
WMS system for warehouse operations management
A system supporting goods receiving, storage, picking and shipping at a manufacturing plant, with a large number of related tables and existing warehouse/production logic to get familiar with before starting work.
Warehouse/production improvements: a form auto-fill mechanism after scanning a product barcode, and automatic reservation of raw materials and products earmarked for production on a specific order.
Warehouse documentation: a system for issuing and managing warehouse documents along with changes to how their printouts are generated, assigning a warehouse to an order, and displaying quantities of produced goods.
AI / Automation
Lead Developer
AI platform for generating songs and music content
A commercial platform using AI to generate lyrics, synthetic voices and music tracks. As the module's lead backend developer, I brought the product to a finished, tested state, ready for production deployment.
Context: a backend responsible for orchestrating content generation across AI models (OpenAI GPT, ElevenLabs, MusicGPT) — text, voice, music, graphics — as part of a commercial client engagement.
Long-running tasks: generation took anywhere from a dozen seconds to several minutes, which caused timeouts in a standard HTTP request. Solution: a background-worker architecture — the API only queued the job, dedicated background services tracked progress and reported completion → stable, fully asynchronous processing under heavy load.
Access limits (STokens): paid AI actions had to be gated behind an active annual subscription with a separate, periodically renewed point budget. Solution: a service validating the subscription and STokens balance, with a full transaction history and token refunds on generation failure → a consistent, auditable system for billing costly AI actions.
AI provider migration: switching to a different music-generation provider, thanks to a shared integration abstraction, initially required only a configuration change, no code rewrite → a well-designed integration with a swappable external provider.
Portals & integrations
Lead Developer
Multilingual CMS for content management
An extensive CMS (public portal, admin panel, intranet, professional exam module) for a nationwide industry organization with around 50 regional branches. As lead backend developer I was responsible for architecture, database and API design, integrations with client systems, security and permissions, plus some frontend work (Next.js/React).
Context: the lead backend developer role — content multilingualism at the database level, dynamic permissions, a professional exam and certification module, Przelewy24 payment integration. Architecture based on DDD and Clean Architecture.
Exam-committee assignment algorithm: a greedy algorithm assigning committee members based on scarcity of required qualifications and workload over the last 365 days → an automatic, balanced committee proposal replacing manual selection, with built-in feasibility validation.
Concurrency and seat limits: risk of overbooking the seat pool under concurrent registrations. Solution: pessimistic locking (
UPDLOCK, HOLDLOCK) at the transaction level + optimistic locking (RowVersion) on editable entities → complete elimination of business errors, 100% transactional data consistency.Branch subdomain system: around 50 regional branches on one shared database and system core, each with its own subdomain, content and local administration → an access matrix controlling visibility by scope (global/branch) and request origin.
Asset management
Lead Developer
System for automating inventory-count processes
A web system supporting a full-scale physical inventory count of fixed assets for a large energy/industrial-sector organization, integrated with the SAP fixed-assets module. Supports multiple committees and count teams working in parallel in the field, partly offline, from a mobile app.
↳ Domain model built essentially from scratch
Context: a system for a large energy/industrial-sector entity, integrating asset data from three sources (SAP FIAA, ZMW, ŚOI); a domain model (committees, count teams, count sheets) built essentially from scratch.
Field work without connectivity: committees scanned assets in halls and yards with unstable internet. Solution: a dedicated endpoint for a batched write of many scans at once (
CreateScans) → data collected offline synced in a single request once the connection is restored.Large-scale work division: automatic generation of count sheets grouped by primary user, business unit, or cost center → the work of around 140 count teams organized by the client's organizational structure instead of manually assigning thousands of items.
SAP integration: asset data imported from the SAP FIAA (Fixed Assets) module and mapped onto the system's domain model, along with a return report updating the last inventory-count date and count-sheet number in SAP → a full data cycle closed automatically, with no manual re-entry.
HR
Finance
System for time tracking and project management
A time-tracking and resource-planning module in a larger, multi-contributor Blunovation product, tied to project budgets — two-step leave approval, a team availability panel, support for 5 languages.
Context: working on self-contained areas (mainly the leave and time-tracking module) in a larger, multi-contributor product sold to external clients and also used internally at the company — backend and frontend (Angular), Clean Architecture.
Leave flexibility: an employee needing to handle something for part of a day formally had to take a full day off. Solution: extended the leave logic with a half-day leave option.
Leave approval process: a two-step flow (manager → HR) with automatic emails at every stage (submission, approval, rejection, return from leave), plus a "today's availability" panel showing which employees are available on a given day and who is on leave.
Project list performance: project, task and leave list views loaded all related timecards up front, slowing down the load. Solution: switched eager loading to on-demand lazy loading, with a new dedicated endpoint returning a single task's data → faster list-view loading.
AI / Automation
Finance
System for automated purchase invoice processing
An application automating the extraction of data from purchase invoices (tax ID, amounts, currency, dates, line items) with an OCR engine (Azure Form Recognizer) and importing it into the database.
Semantic validation of the OCR result: a raw read doesn't guarantee correctness — a dedicated layer on top of the OCR output (tax-ID checksum verification, recognizing currency codes in text), covered by unit tests → misread data is caught before further processing.
Human-in-the-loop verification: the backend returns bounding boxes for recognized fields, the frontend highlights them on the invoice scan and allows manual correction before saving → the user verifies and corrects the data instead of blindly trusting the automated read.
Accessibility / education
Presentation-authoring app for blind and low-vision users
Accessibility instead of WYSIWYG: popular presentation tools (PowerPoint, Impress) are poorly accessible to blind users because they rely on direct graphical manipulation. Solution: an interface based entirely on structured forms, with full ARIA support and keyboard navigation → WCAG 2.0 compliance confirmed by an automated HTML validator.
File generation: reading presentation data with slides and elements from a relational database and programmatically recreating them in a PowerPoint application object → export to PPTX/PDF/PNG in around 1.5s, within the target performance requirement (under 5s).
The app was manually tested with a real blind user and one low-vision user (creating presentations independently), with no accessibility or functionality issues reported.
AI / Automation
Manufacturing / infrastructure
Object detection and counting system for the production process
Joining the project required independently picking up a new field (computer vision models, Intel OpenVINO) — I had previously only worked in the related but distinct area of OCR.
Demo features: counting objects crossing a designated line, counting bottles within a time window and calculating a rotations-per-minute rate, detecting water-film conditions on a product, alerting when an employee enters a designated hazard zone.
Finished, technically advanced versions of the demo features are used in presentations to prospective clients in the manufacturing sector.
Manufacturing / infrastructure
Lead Developer Mobile app for managing alarm systems
An independent migration of a mobile app (Android/iOS) from Xamarin to Qt/QML + C++, with no prior experience in either technology — communication with alarm panels over MQTT (Mosquitto broker), native iOS extensions (Touch ID, push notifications), App Store publication.
Access management: scripts generating and updating the MQTT broker's ACL files (a separate file per user), with automatic configuration reload after a permission change.
Panel communication stability: the alarm panel could reset after receiving several MQTT messages at once, and partition state sometimes went out of sync between the panel and the app. Solution: improved message-handling and state-sync logic, plus disabling UI actions unavailable in a given state → more stable communication and elimination of invalid user actions.
Accessibility / education
System supporting academic process organization
A course system (LMS) for the Institute of Computer Science at UPH — a lab-assignments module designed and built from scratch, where instructors publish assignments with a maximum point value and students submit solutions and projects for grading.
Grade-change history: changes to points awarded to students had no history at all. Solution: a dedicated model recording every point change with a date and a link to the specific participant and class → the ability to trace grading history.
Attendance-list automation: instead of building a custom Google Meet integration, importing the attendance list directly from the export of a popular, ready-made browser extension for that purpose → a fast, pragmatic solution instead of a costly API integration.
Asset management
Asset register and inventory system
An extensive asset register system, deployed at several clients — including a public-sector body and a leader in the healthcare sector. Full asset lifecycle (intake, transfer, disposal, upgrade) with a configurable, multi-step document approval process.
Accountability during staff turnover: when an employee left (automatically removed from Active Directory), their assigned assets could become "orphaned". Solution: extended AD sync to check assigned assets and automatically email the manager.
ServiceNow integration from scratch: a ServiceNow API integration built from the ground up (XML parsing, mapping to the domain model) → a new asset data source integrated automatically, with no manual re-entry of client data.
Portals & integrations
Reporting and cybersecurity systems for a global container-terminal operator
Targeted technical support on two internal systems for a global container-terminal operator: a KPI reporting and benchmarking tool covering over a dozen terminals across several regions, and a terminal cybersecurity assessment portal.
Distinguishing annual data: KPI input data entered by terminals didn't distinguish data groups meant only for the annual report from data reported monthly. Solution: added a flag marking annual data in the input templates and factored it into Excel report generation.
Data import stability: Excel data imports were failing in production, blocking terminals from submitting reporting data. Solution: analyzed and fixed the input-validation logic → a stabilized import mechanism used by terminal administrators.
Stack modernization: independently upgraded the backend (.NET 8→10 LTS, C# 14, EF Core 8→10, Microsoft Graph SDK 5.x→6.x) and adapted the frontend to Angular 21 (migrated the build to esbuild, converted components to standalone, introduced Vitest and ESLint, upgraded MSAL v4→v5) → an up-to-date, consistent technology stack across both layers.
Finance
Portals & integrations
Analytics system integration with SAP FC
An accounting-data reconciliation system between a COGNOS database and the SAP FC module for the client's finance/controlling department — automatic account and company mapping, reconciliation rules, exchange-rate handling, recurring exports and email notifications.
Legacy stack modernization: independently carried out a comprehensive upgrade of an outdated stack (.NET 6→10 LTS, C# 10→14, EF Core 6→10, Angular 14→21) on a production system integrating financial data → an up-to-date, long-term-supported (LTS) stack.
Mapping data integrity: risk of duplicate Cognos/SAP accounts and companies when creating or updating mapping data. Solution: uniqueness validation on create/update operations → preserved consistency of data reconciled between systems.
Portals & integrations
Shared identity and permissions service
An internal authentication, user, role and permission management service, shared simultaneously by several independent internal systems (including the CMS, CMMS, and inventory systems).
GDPR compliance: designed and implemented a complete self-service and admin account deletion/anonymization mechanism, accounting for the user's activity in the connected system before deletion → safe account removal without losing data still needed on the other side of the integration.
Self-initiated security review: during my own code review (no external audit involved) I found and fixed three independent vulnerabilities — passwords leaking into logs, log injection, and email enumeration on password reset.
Experience
07/2025 — present
Developer / Analyst
Blunovation Sp. z o.o. · B2B contract
02/2021 — 07/2024
Developer / Analyst
Blunovation Sp. z o.o.
Show earlier internships (2014–2020)
07/2020 — 09/2020
Intern
Blunovation Sp. z o.o.
06/2020 — 08/2020
Trainee
Instytut Informatyki UPH w Siedlcach
01/2016 — 02/2016
Trainee
Urząd Gminy Łomazy
07/2014 — 08/2014
Intern
RAM-SERWIS Sp. z o.o.
Certificates
Umiejętności Jutra AI
2026
2026
C2 Proficient · 80/100
2026
2026
Builder · Architect · Champion
2026
2026
OSINT & OPSEC Basics
2026
2026
Polish AWSome Week
2021
2021
Risk & quality management, ISO audit
2020
2020
Git – Version Control
2019
2019
Show remaining courses and certificates (11)
11/2020 – 12/2020
React and AngularJS programming course
11/2020
"Effective Team Building" course — communication and conflict resolution within a team
11/2020
"Communication, Self-Presentation, Assertiveness" course
05/2020
"Technical Analysis in Risk Management" certificate
05/2020
"Quality Management Systems" certificate
02/2020
"Lead Auditor of an Information Security Management System" certificate
11/2019
"Git – Version Control System" certificate
03/2017
Vocational qualification "E.14. Building Web Applications and Databases, and Database Administration"
08/2016
Vocational qualification "E.13. Designing Local Computer Networks and Network Administration"
08/2015
Vocational qualification "E.12. Assembly and Operation of Personal Computers and Peripheral Devices"
08/2014
Certificate of participation in the national internship program "Gain Professional Experience"
References
PG
Piotr Gryczka
Fullstack Developer (.NET/PHP/Java) · same team
I had the chance to work with Przemek on .NET projects, and he's definitely a developer worth recommending. He delivers on tasks, works in an organized way, and understands what he's doing — he doesn't work by rote, he actually analyzes problems. He's clear in his communication and works well as part of a team.
JS
Jarosław Sopiński
Fullstack Developer (React, Next.js, .NET) · same team
Based on several years of working with Przemek on various projects, I can confirm he's an excellent professional — he always delivers to a high standard, shows great knowledge, competence and experience, and works excellently within a team.
AS
Adrian Sztandera
Fullstack Developer · .NET Backend / React · same team
I had the chance to work with Przemek on the backend, and I have very good memories of that collaboration. He gets on top of things, takes a concrete approach to tasks, and you can rely on him. Without unnecessary complications, he gets the job done right. I'd gladly work together again sometime.
RD
Rafał Drzał
PHP Developer & Code Exorcist · manager (indirect)
I'm happy to recommend working with this specialist. I had the chance to hand him tasks across many shared projects and was always impressed by his approach. He's a developer who not only codes excellently but, above all, thinks analytically and understands the business purpose of what he's building.
On the technical side he's a very strong figure — he moves comfortably within the .NET, C# and ASP.NET ecosystem, and his knowledge of relational databases and SQL (especially MS SQL Server) has saved a project more than once. What sets him apart is his openness to new technologies, such as AI or blockchain, which he can implement effectively in web applications.
Besides a great technical toolkit, he has a skill rare among developers — managing a team and a project. He can look at a system holistically, plan the work, and deliver high-quality software.
On the technical side he's a very strong figure — he moves comfortably within the .NET, C# and ASP.NET ecosystem, and his knowledge of relational databases and SQL (especially MS SQL Server) has saved a project more than once. What sets him apart is his openness to new technologies, such as AI or blockchain, which he can implement effectively in web applications.
Besides a great technical toolkit, he has a skill rare among developers — managing a team and a project. He can look at a system holistically, plan the work, and deliver high-quality software.
All recommendations come from real colleague reviews — see the originals on LinkedIn
Contact
Timezone: CET/CEST. I usually reply within 24h. Open to B2B contracts, ongoing engagements, and single projects.