Ing. Marek Krištof

Senior full-stack engineer · Java · Spring Boot · Angular · Camunda 8

Marek Krištof — Senior full-stack engineer

I design, build and run software, from banking platforms to company websites.

For 8+ years I've been building and running business-critical systems in finance — tax reporting for a global reinsurer, banking processes on Camunda 8. Through my company, KriSoft s.r.o., I join teams as a senior contractor and design, build and run custom websites and web apps for businesses — from first draft to hosting and updates.

Get in touch See my work
Portrait of Marek Krištof

Services

Two ways I can help.

Need a senior engineer on your team, or someone to build your website or app? Same person, same rigor.

For companies & teams · Enterprise contracting

Does your team need a senior engineer?

A senior Java / Spring Boot and Angular engineer who joins your team on contract via KriSoft s.r.o. and takes real ownership — remote, invoiced B2B.

  • Backend services and APIs in Java & Spring Boot
  • Angular frontends for complex, data-heavy applications
  • Azure, CI/CD and process orchestration with Camunda 8
  • Architecture reviews and a pragmatic second opinion
Discuss a contract

Experience

8+ years of building software — most of it in finance.

I'm a developer from Košice. I've been building software for more than 8 years, mostly for banks and insurers, so I got used to doing things properly the first time.

What I enjoy most is solving complicated problems, from idea to production. I care about clean code and clean architecture. I spot antipatterns early and would rather point them out than let them grow.

When I take something on, I treat it as mine. I want it to be fully working, and a happy customer is the best reward for me.

I'm proactive, I like learning new things, and I like meetings with a structure. I'm happy to help colleagues. When something breaks in production, I'm usually the first to jump in.

Selected work.

Aug 2026 – present

Client-onboarding migration to Camunda 8

Prvá stavebná sporiteľňa Banking

Full-Stack Developer (contract) · Aardwark s.r.o.

A bank's core client-onboarding process moved from a legacy IBM BAW platform to Camunda 8 — rebuilt as a Spring Boot microservice that behaves exactly like the original. Identity and compliance checks, documents with e-signing, cancellation — plus integrations with a national registry, identity verification and the bank's internal systems.

Every process covered by end-to-end tests against real Kafka and object storage.

  • Java
  • Spring Boot
  • Camunda 8
  • BPMN / DMN
  • Kafka
  • Docker
Nov 2021 – Jul 2026

Group tax calculation & reporting platform

Swiss Re Global reinsurer

Full-Stack Developer (contract) · Aardwark s.r.o.

Tax calculation and reporting across IFRS and US GAAP for a global reinsurer. I designed and built the IFRS tax system and owned the architecture of its high-throughput data loads: bulk-loading data for many legal entities at once, then processing it entity by entity with transformations, reconciliation and error reporting, driven by Azure Service Bus events and REST state sync. I made the core data-generation process fast and resilient — async and multithreaded, with Resilience4j throttling, bulkheads, time limits and retries. I also led the Angular frontend, was the first line of response for critical issues, and reviewed code and mentored colleagues every day.

Nearly five years keeping a business-critical system correct, fast and in production.

  • Java
  • Spring Boot
  • Angular
  • Azure
  • CI/CD
Apr 2021 – Oct 2021

Mutual-fund purchase modules

Deutsche Börse European exchange operator

Full-Stack Developer (contract) · Aardwark s.r.o.

Modules for buying mutual funds at a European exchange operator — work where every number has to be right.

  • Java
  • Spring
  • Angular
  • Oracle
  • REST
Sep 2020 – Jan 2021

Internet banking for a major bank abroad

International Bank of Azerbaijan (ABB) Banking

Java Developer · BSC SK s.r.o.

Back-end development of an internet banking system for a major foreign bank, plus improvements that raised software quality and reduced technical debt.

  • Java
  • Spring
  • Liferay
  • Hibernate
  • Oracle
  • SOAP
Oct 2019 – Sep 2020

Instruction-processing engine for myGEMINI Digital Bank OS

Banking Software Company (BSC) Banking

Java Developer

Developed a configurable engine for processing banking transactions in BSC's product myGEMINI Digital Bank OS, designed for reusability and clean integration across diverse client requirements.

One engine, reused across multiple clients.

  • Java
  • Spring Boot
  • QueryDSL
  • Elasticsearch
  • Docker
Feb 2018 – Jul 2019

Cross-platform mobile app for young athletes

Nordlicht IT Solutions Sports · mobile

Java Developer

Built a cross-platform mobile app for young football players with CodeNameOne, delivering consistent behaviour across Android and iOS from a single codebase.

One codebase for both Android and iOS.

  • CodeNameOne
  • Android
  • iOS

Own project.

Dark-mode screenshot of RunZones showing a 10 km run in 50:00 with the equivalent race times Own product Pace calculator and training zones for runners A minimalist calculator for live pace, time and distance, plus training zones derived from Jack Daniels' VDOT and a recent race result. Open the app ↗
Show earlier roles & academic projects (5)Hide earlier roles & academic projects

Earlier roles and side projects — from QA to university work.

  • Aug 2019 – Oct 2019

    Java Developer · Unicorn s.r.o.

    Legacy Java Swing desktop application for the banking sector.

    Banking

  • May 2017 – Dec 2017

    QA Tester · Inlogic Software s.r.o.

    QA for Android, iOS, HTML5 and J2ME games.

    Games · QA

  • Master's thesis

    Athlete movement monitoring system

    A system to track and analyze athletes' movement — a Spring / Hibernate backend with a CodeNameOne + React client and ESP32 sensors feeding the data.

    Sports · IoT

  • University team project · team lead

    Public-transport route planner for Košice

    An app built by a team I led, finding the best public-transport connections across Košice and computing optimal routes with Dijkstra's shortest-path algorithm.

    Public transport

  • Bachelor's thesis

    AR learning app for children with disabilities

    An interactive educational application using augmented / virtual-reality techniques (JavaFX + NyARToolkit) to help children with disabilities learn.

    Education · AR

Certifications

  • Azure Developer Associate AZ-204Azure Developer Associate (AZ-204)
    Microsoft
  • Azure Fundamentals AZ-900Azure Fundamentals (AZ-900)
    Microsoft
  • Azure AI Fundamentals AI-900Azure AI Fundamentals (AI-900)
    Microsoft
  • Spring Professional 2021Spring Professional (2021)
    VMware

Education

Computer Science
Technical University of Košice · 2014–2019

Languages

  • English — professional
  • Slovak — native

Outside work

  • Endurance running & trail racing
  • Specialty coffee

Recommendations

What colleagues say.

Excerpts from recommendations on my LinkedIn profile, quoted as written.

He inherited a multi-application data flow that originally required 4 developers to manage—and for the past 2 years, he’s handled it solo while actively redesigning and improving the architecture.

JakubDevOps & cloud consultant · 5 years on the same project

Rather than staying in his comfort zone, he quickly picked up Angular and delivered a frontend that was extremely well-received by our stakeholders.

MariánSenior IT manager · my direct manager

He never rushed to the first answer; he’d stay with a problem until it was genuinely solved … he picked up whatever work needed doing — not only the interesting parts, but the tedious, thankless ones too.

DaliborBusiness analyst · 4 years on the same team

He didn’t just fix what was broken — he often identified the root cause and prevented future issues along the way.

MarošQA engineer · 3+ years on the same project

See all recommendations on LinkedIn ↗

Stack

Tools I use in production.

The core I work with every day — expand to see everything I've shipped with.

  • Java
  • Spring Boot
  • Camunda 8
  • TypeScript
  • Angular
  • RxJS
  • Hibernate / JPA
  • PostgreSQL
  • Oracle
  • Microsoft Azure
  • Azure DevOps
  • Docker
  • JUnit
  • Claude Code
Show all toolsShow core only

Languages

  • Java
  • TypeScript
  • SQL
  • C#
  • C

Backend

  • Spring Boot
  • Spring
  • Hibernate / JPA
  • QueryDSL
  • MapStruct
  • REST
  • SOAP
  • OpenAPI / Swagger
  • Microsoft Graph
  • Resilience4j
  • OAuth2

Process automation

  • Camunda 8
  • BPMN
  • DMN

Frontend

  • Angular
  • RxJS
  • HTML / CSS / JavaScript
  • AG Grid
  • React
  • Bootstrap
  • Material Design
  • JavaFX
  • CodeNameOne
  • Unity

Data & storage

  • Oracle
  • PostgreSQL
  • MySQL
  • Elasticsearch
  • MongoDB
  • Redis
  • Databricks

Cloud & DevOps

  • Microsoft Azure
  • Azure Service Bus
  • Azure DevOps
  • AWS
  • Docker
  • Open Liberty
  • Jenkins
  • Maven
  • Node.js
  • npm
  • Git
  • CI/CD

AI & LLMs

  • Claude (Anthropic)
  • Claude Code
  • OpenAI
  • Azure AI
  • AI-assisted development

Testing & quality

  • JUnit
  • Mockito
  • Wiremock
  • TestNG
  • Newman
  • SonarQube
  • ESLint
  • Prettier
  • Spotless
  • Checkstyle
  • PMD

Tools & ways of working

  • IntelliJ IDEA
  • Eclipse
  • Postman
  • Jira
  • Confluence
  • Bitbucket
  • Sourcetree
  • Oracle SQL Developer
  • HP ALM
  • Scrum
  • Waterfall

Earlier / legacy

  • Java Swing
  • IBM WebSphere
  • Apache Ant
  • NTLM

Exploring on the side — personal experiments, not client workLocal LLMs / OllamaGenerative AINLPMulti-agent systems

Contact

Let's work together.

Have a project, a role, or just a question? Tell me a bit about it and I'll get back to you within one business day. We can start with a free, no-obligation call.

  • Response within one business day
  • Košice, Slovakia · working remotely
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