Артем

ARTEM DEMCHYSHYN
[open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section) | TW8, London, UK | LinkedIn | GitHub

PROFESSIONAL SUMMARY

Java Backend Developer based in London, building production-style backend systems, open-source libraries, and AI-assisted workflow
products with Java 17/21, Spring Boot, Spring Security, JPA/Hibernate, SQL, Docker, and GitHub Actions. Creator of GraphCompose,
a Maven Central-published modular document layout engine with deterministic two-pass layout, automatic pagination, pluggable
rendering backends, and regression testing. Also built CVRewriter, an end-to-end Spring Boot and React platform combining resilient
vacancy scraping, provider-agnostic AI orchestration, real-time SSE progress, JWT security, encrypted persistence, Stripe billing, and PDF
generation. Focused on clean architecture, secure API design, automated testing, documentation, and maintainable delivery.

TECHNICAL SKILLS

Languages: Java 17/21, SQL, TypeScript and JavaScript (working knowledge), Kotlin (basic)

Backend: Spring Boot 3/4, Spring MVC, Spring Security, Spring Data JPA, Hibernate, REST API design, DTO mapping, Jakarta Bean
Validation, Lombok, MapStruct

API & Security: JWT authentication, role-based access control, short-lived scoped tokens, BCrypt, AES-GCM encryption, email
verification, CORS, ownership validation, RFC 7807 problem details, Swagger/OpenAPI

Databases: MySQL, H2, Oracle SQL, SQLite, relational database design, Flyway migrations

Testing: JUnit 5, Mockito, AssertJ, H2 integration testing, Vitest, Playwright E2E, layout snapshot testing, visual regression testing

Tools & DevOps: Git, GitHub, Maven, Docker, Docker Compose, GitHub Actions, Nginx, IntelliJ IDEA

Document & AI Systems: GraphCompose, Apache PDFBox, Apache POI, PDF generation, semantic DOCX export, Server-Sent Events,
Playwright scraping, Gemini/OpenAI/DeepSeek API integration, schema-validated JSON outputs, token usage tracking

Core Java: OOP, Collections, Streams API, Records, Optional, IO/NIO, JDBC, multithreading, ExecutorService, concurrency fundamentals,
ServiceLoader/SPI

PROJECTS

GraphCompose
(Java 17/21, Apache PDFBox, Apache POI, Maven, JUnit 5, GitHub Actions)

Created and maintain an open-source, Maven Central-published Java document layout engine for server-side CVs, invoices, reports,
proposals, and other structured business documents. Recorded 6,400+ downloads from 441 unique sources over three months, with
analytics showing activity associated with 119 organisations. Designed a semantic DSL, deterministic two-pass measurement/layout
pipeline, automatic pagination, modular core, and ServiceLoader-based rendering backends, with layout snapshots and pixel-level visual
regression testing. Shipped the 2.0 module split with production PDF rendering, opt-in semantic DOCX export, templates, migration
guides, CI, examples, benchmarks, documentation, and versioned releases.

CVRewriter
(Java 21, Spring Boot 4, Spring Security, JPA/Hibernate, MySQL, Flyway, React 19, TypeScript, Docker Compose, Playwright, SSE, Stripe)

Designed and built a full-stack platform that turns a job URL into a tailored, editable CV and downloadable PDF. Implemented
HTTP/JSON-LD scraping with Playwright fallback, a provider-agnostic AI layer for Gemini, GPT, and DeepSeek with schema-validated
structured output, six-stage SSE progress using short-lived scoped JWTs, AES-GCM encryption at rest, audit history, token tracking, Stripe
subscriptions, 28 Flyway migrations, and isolated production/development/test Docker environments. Published a public architecture
showcase covering the data flow, security model, technical decisions, screenshots, and trade-offs while keeping the production source
private.

Spring Cart API
(Java 17, Spring Boot 3.4, Spring Security, JPA/Hibernate, MySQL, Flyway, MapStruct, Docker, OpenAPI)

Developed a production-style e-commerce REST API for products, shopping carts, and cart items. Implemented JWT authentication,
admin/user role-based authorization, pagination, filtering, rate limiting, Jakarta Bean Validation, DTO mapping, Flyway migrations,
Docker Compose setup, and Swagger/OpenAPI documentation.
 PROFESSIONAL EXPERIENCE

Independent Software Developer Apr 2024 – Present
London, UK

Designing and releasing open-source Java libraries and production-style backend products. Own architecture, implementation, security,
persistence, automated testing, CI/CD, Maven Central publishing, documentation, issue tracking, and release management across
GraphCompose, CVRewriter, Spring Cart API, and supporting developer tools.

Bartender Aug 2022 – Present
Caprice Holdings – Scott's Richmond, London, UK

Work in a fast-paced, high-standard hospitality environment requiring clear communication, reliability, attention to detail, and teamwork;
promoted within 7 months for consistency and performance.

Lead Engineer Sep 2016 – Feb 2022
Nikoplast, Odesa, Ukraine

Led engineering work across planning, execution, quality control, and delivery; improved workflows, maintained quality standards,
coordinated technical work, and mentored 8 team members.

EDUCATION & CERTIFICATIONS

Backend Engineering with Java & Spring Apr 2024 – Present
Independent Study and Project Development

Spring Boot, REST APIs, Spring Security, JPA/Hibernate, testing, Docker, database migrations, and production-style backend architecture
applied through public and private projects.

Oracle SQL Course Jan 2024 – Jun 2024
Self-Study

DDL/DML, joins, transactions, views, sequences, relational database fundamentals, and Oracle SQL tooling.

Advanced Java Course (OCA-aligned) Dec 2023 – Jan 2024
Self-Study

Multithreading, Streams API, JDBC, functional programming, collections, reflection, and advanced Java fundamentals.

BSc in Hydraulic Engineering Sep 2012 – May 2017
Kherson State Agrarian and Economic University, Ukraine

(UK equivalent: 2:1)

ADDITIONAL INFORMATION

Languages: English (Professional Working Proficiency), Ukrainian (Native), Russian (Native)

Work Eligibility: Right to work in the UK