Work Experience
Lena Sędkiewicz
Software engineer specialising in building secure web applications. I combine hands-on programming experience (TypeScript, JavaScript, React, Node.js, Java) with deep knowledge of cybersecurity and cyberpsychology — OWASP standards are part of my everyday toolkit.
I am expanding my knowledge of AI and prompt engineering. I regularly speak at industry conferences.
My longer-term goal is to become a Security Champion — a software engineer who bridges the worlds of development and cybersecurity, writing code that is not only functional but secure by design.
- TypeScript
- JavaScript
- Java
- PHP
- SQL
- GraphQL
- REST API
- Node.js
- MongoDB
- React
- Vue
- Spring
- Spring Boot
- Tailwind
- Laravel
- Gatsby
- Vite
- Docker
- Kubernetes
- Kafka
- Prometheus
- Grafana
- Postman
- Burp Suite
- Google Tag Manager
- Screaming Frog
- Jest
- unittest
- AWS
- Microsoft Azure
- TDD
- WordPress
- CSS
- SASS
- HTML
- Responsive Web Design (RWD)
- Webflow
- Kali Linux
- Security Awareness
- Accessibility
- Technical SEO
- Git
- GitHub
- GitLab
- Scrum
- Kanban
- Jira
- ClickUp
- Trello
- Visual Studio Code
- PyCharm
- Polish: C2
- English: C1
- German: A1
- French: A1
Bayer, Warsaw, Poland (hybrid) — Intern Software Engineer
April 2026 - present
- I co-develop and maintain software within the Crop Science division (TypeScript, JavaScript, React, Node.js, AWS)
- I work in a cross-functional team: close collaboration with a Product Specialist, QA and security teams, and directly with stakeholders
MSedkiewicz, Warsaw, Poland - self-employed (Fullstack Developer, freelance)
May 2023 - April 2026
- I create websites: from consulting clients and assessing business needs, through designing the initial graphics or collaborating with a designer, coding and testing the site, to maintaining and updating it.
- I optimize websites for technical SEO and ensure their security and accessibility.
- I implement web application security measures based on standards like the OWASP Top Ten and OWASP ASVS, and use AI ethically in the development process (code review, documentation generation, test-writing support).
- 15+ completed projects for individual clients and small to medium-sized enterprises, including on-site technical and cybersecurity support.
Selected projects
Advertising Platform for a Real Estate Client (NDA; February 2024 - May 2024)
- I collaborated on the application development with BackEnd, UX/UI, Manual Testing, SEO and DevOps specialists
- I created new components and views for the project's application (Vue) and website (WordPress)
- I did technical SEO optimisations
- I tested the code developed for application (including regression tests).
KKS Lech — football club fan portal
- Development and deployment of a visually refreshed version of the website, supplemented with new functionalities (e.g., commenting for non-logged-in users) and performance improvements
Polub Dentystę — dental clinic website
- Development and deployment of a new version of the website optimized for technical SEO, accessibility and security; ongoing project maintenance
Code First Girls (remote) — +Masters (Java) & Mid Level Accelerator
November 2025 - April 2026
- In a five-person team working in sprint-style cycles I co-developed a microservice application (NDA): improving deployment efficiency through CI/CD, hardening application security, and shipping new features
- I initiated many of the team's activities and was a driving force behind organising our work
- Technologies: Java, Spring, Spring Boot, TDD, Docker, Kubernetes, Kafka, Prometheus, Grafana
Wyższa Szkoła Biznesu - National Louis University, Nowy Sącz, Poland — Guest Lecturer
October 2024 - March 2025 · October 2025 - March 2026
- I taught the Cyberpsychology course: digital accessibility, disinformation, digital hygiene, and safe online practices
- I built awareness of the human factor in cybersecurity and critical thinking around AI and modern technologies
Tech Leaders Program, Kraków — Fullstack Developer Mentee
February 2025 - June 2025
- Intensive backend upskilling under the guidance of a Senior Fullstack Developer: database architecture, backend architecture, REST API and database design (React, TypeScript, Node.js, MongoDB)
- Practical Agile project work: MVP planning, task estimation and sprint planning
Onely, Texas, USA — Junior Web Developer
November 2021 - April 2023
- I created components and functionalities that improved the page architecture and metrics related to the website's technical SEO
- I refactored website's code and worked on reducing its cyberattack surface
- I supported the marketing team in website management, provided training on website maintenance, implemented new solutions related to the website, and assisted in optimising tools associated with the website and marketing (e.g., Google Tag Manager)
Lena Inspirations, Warsaw, Poland — self-employed
June 2016 - December 2021
- Own business at the intersection of psychology, education and content: BSFT therapy, psychology lectures and workshops, copywriting for the IT industry
- Transferable skills I use in engineering daily: communicating with diverse stakeholder groups, teaching, analytical thinking and problem-solving
SWPS University, Warsaw, Poland
2010-2017
Master's degree in General Psychology (studied in English language)
Physical Education Academy (AWF), Katowice, Poland
2017-2019
Postgratuate studies: IInd degree coach (fencing)
WSNOZ, Warsaw, Poland
2019-2020
Postgratuate studies: pedagogical training
- "From 0 to pentester" — course by Kacper Szurek
- Sekurak Academy — ongoing cybersecurity upskilling
- TryHackMe (since June 2026)
- "Za Rączkę" mentoring program (01/2025 - present) — Java, Python and backend development; selected projects: socket communicator app, Snake game, console checkers
- Sekurak Academy (participant; 01/2024 - present) — cybersecurity upskilling
- Securitum Publishing House — psychological commentary in Robert Kruczek's book "Socjotechnika w praktyce. Triki i kruczki hackowania ludzi" (Social Engineering in Practice)
- Not The Hidden Wiki (03/2025 - present) — creating a podcast about digital hygiene
- WarsawJS Meetup (04/2023 - 08/2024) — volunteer, photographer
Psychology Specialist (2017-2021): psychotherapy in an addiction treatment centre (Brief Solution-Focused Therapy), psychology lectures and workshops at a post-secondary school (Go Work, 2018-2020), and marketing content for IT-industry training and software. Earlier also: fencing classes, social media and marketing strategies.
- Photography
- Fencing (epée, longsword)
- Formula 1
- Premier League
- Crocheting
- board games (especially Terraforming Mars, Calico, Azul)
- cyberpsychology
- resilience
- HSP
- social psychology
- BSFT