An international technical software development conference
About The Event
DEV: Challenge Accepted is a full-day single-track conference for software developers of all levels. The conference focuses on the latest trends and technologies in the industry, providing attendees with the opportunity to learn from experienced professionals and network with their peers. Frontend, backend, full stack, QA, DevOps, Managers - it's a great opportunity for everyone to stay up-to-date with the latest developments in their field and gain valuable insights from industry leaders. For our fourth edition, we would like to welcome you on September 28, 2025, at the John Atanasoff Forum in Sofia, Bulgaria. With a focus on providing valuable content and fostering a sense of community among attendees, DEV: Challenge Accepted - The Elevation is an event not to be missed for any software developer.
What is it like? Check it out:
Currently available: Early bug tickets
By buying a ticket, you get:
- Full onsite and online access to the conference.
- Unlimited networking opportunities to connect with like-minded tech enthusiasts
- Unlimited coffee to keep your energy high throughout the day
- A tasty lunch to fuel your learning and networking sessions
- Access to sponsor booths, offering insights into cutting-edge tech solutions
- An opportunity to interact directly with speakers in the Speakers Corner
- Chance to win exciting prizes from sponsor raffles
- All the fun of meeting old buddies and making new friends in the tech community
- ... and many more!
Haven't decided yet?
Register for news and get online access to the conference absolutely free of charge.
Not sure about coming over?
Come on - the combined cost of your flights, accommodation, and a full-access conference ticket here is often less than just a basic entry pass at some other events. Thanks to our sponsors, it is not only a budget-friendly event, but you also get the complete experience - comprehensive learning, extensive networking, and the chance to explore the vibrant culture of a charming EU country - Bulgaria . Reach us if you need any help for visas, travel, and accommodation - we will be happy to help.
Event Schedule
28 Sep 2025 (Sunday)
09:00-09:30
Login
Badge pickup, coffee, networking
09:30-09:50
Opening Ceremony
Opening with our well-known hosts Vladislav Violinov and Toni Karabashev
09:50-10:20
🎤 Build Successful Teams & Remain Profitable in the Age of AI and Economic Change
Hashtags: #Leadership #Teams #AI #Economics #Inclusion #BusinessGrowth #TeamStructure
Suitable for: Everyone
Thrive through change. In a world of shrinking budgets and rising expectations, building resilient, profitable teams is no longer optional — it’s survival. Maria will start the conference and show strategies to lead smarter, scale faster, and future-proof your business without sacrificing quality or control. This session is designed for agency owners, project managers, and technical leads striving to maintain profitability amidst the economic uncertainty and AI boom. She will also share strategic approaches to structuring modern teams that drive profitability and growth even in uncertain times. Walk away with actionable frameworks, real-world examples, and future-ready strategies to scale smartly, enhance profitability, and lead your teams confidently into the next era.

Maria Totova-Cholakova
💼 Founder & CEO of IT Talents Academy
💼 Chairperson of Drupal Bulgaria Association
🚗 Plovdiv, Bulgaria
Maria is the founder and CEO of IT Talents Academy, a dynamic Bulgarian company, delivering smart outsourcing and talent development solutions to businesses across Europe. She also serves as the chairperson of the Drupal Bulgaria Association, actively contributing to the open-source community. With a background as a developer, team lead, and university instructor, Maria brings a wealth of experience to her leadership roles. She is a passionate advocate for diversity and inclusion in the tech world and is dedicated to fostering the next generation of IT professionals.
10:40-11:10
🎤 Let’s Build AI That Will Replace You
Hashtags: #AI #AIAgents #Automation #LiveCoding #CodingAssistants #DeveloperTools
Suitable for: Backend, Fullstack, AI/ML Developers, DevOps, Management, Technical QA
AI Agents are the next big thing everyone has been talking about. They are expected to revolutionize various industries by automating routine tasks, mission critical business workflows, enhancing productivity, and enabling humans to focus on creative and strategic work. But can they really replace developers? Alex takes us on a hands-on journey into the world of AI Agents — what they can do, what makes AI coding agents fundamentally different from basic LLMs, and why they are positioned to redefine how software gets built. Expect a live demo showing how to build and use your own agent, ready to boost productivity from day one. All of the code will also be available for people to play with, and they will be able to apply what they've learned right away essentially.

Alex Shershebnev
💼 Head of ML/DevOps, DevRel @ Zencoder
✈️ Funchal, Portugal
Alex is a seasoned engineering leader with a passion for building high-performing teams and scalable systems. With over 15 years of experience in the software industry, he has a proven track record of delivering innovative products and driving technical excellence. Alex is a strong advocate for open-source and is an active contributor to several projects. He is also a frequent speaker at international conferences, sharing his insights on topics ranging from machine learning to DevOps.
11:10-11:40
🎤 Unlock Peak Productivity with Model Context Protocol
Hashtags: #AI #Embeddings #VectorDatabases #Infrastructure #Productivity #Tools
Suitable for: Backend, DBA, Fullstack, AI/ML Developers, DevOps, Tech Leads, Architects
AI promises to revolutionize software development, but fragmented tools and complex integrations often bottleneck its potential. The Model Context Protocol (MCP) presents a practical, standardized approach to mitigate these issues. Nikolay will provide a concrete overview of MCP and illustrate its application through specific use cases. We will see how developers, QA engineers, and architects can leverage it today to slash integration overhead, automate tedious tasks, and build truly intelligent, context-aware workflows. We'll touch upon the growing ecosystem, security considerations, and how you can begin experimenting with MCP to drive real efficiency improvements in your daily tasks.

Nikolay Stoitsev
💼 Senior Engineering Manager @ StorPool Storage
📌 Sofia, Bulgaria
Nikolay is a Senior Engineering Manager at StorPool Storage, where he leads the development of high-performance software-defined storage solutions. With a deep expertise in distributed systems, he is passionate about building reliable and scalable infrastructure. Nikolay is a regular speaker at tech meetups and conferences. When he's not architecting storage solutions, he enjoys spending time with his kids.
12:00-12:30
🎤 How Google built Zanzibar
Hashtags: #Authorization #Zanzibar #Security #Scalability #DistributedSystems #GoogleScale
Suitable for: Backend, Fullstack, DevOps, AI/ML Developers, Management, Architects, Security Engineers
Sohan will cover the design and implementation of Zanzibar, Google's globally distributed authorization system. We will explore the challenges of building a scalable and consistent permission system and how Zanzibar addresses them. The session will delve into the core concepts of Zanzibar, including its data model, consistency models, and API. We will also discuss how Zanzibar is used at Google to power authorization for services like YouTube, Google Drive, and Google Cloud. At the end, you’ll gain insights into how Zanzibar enables fine-grained, flexible access control at scale.

Sohan Maheshwar
💼 Lead Developer Advocate @ AuthZed
✈️ Amsterdam, The Netherlands
Sohan is the Lead Developer Advocate at Authzed, where he helps developers build secure and scalable authorization systems. Sohan is a frequent speaker at international conferences, sharing his expertise on topics such as Authorization, Cloud and AI. In his free time, he enjoys visual arts, trivia, and playing frisbee.
12:30-13:00
🎤 GitHub Actions: Cloudy with a Chance of CI/CD
Hashtags: #CI/CD #GitHubActions #Automation #CloudNative #Workflows
Suitable for: DevOps, Backend, Fullstack, QA, Tech Leads, Management
GitHub Actions has become one of the most popular choices for automating software workflows directly in your repository. In this session, Sefo will demonstrate the power of GitHub Actions for building robust and scalable CI/CD pipelines. You will learn the fundamentals — workflows, jobs, and steps — and how to extend them with custom or community-contributed actions. We'll dive into secure secrets management, job matrices, caching, conditional execution, and environment-based deployments. Finally, you’ll walk away with best practices for pipeline design, including testing strategies, deployment models, monitoring techniques, and actionable insights to automate smarter.

Serafim Karparov
💼 Software Architect @ IBM
📌 Sofia, Bulgaria
Serafim is a Software Architect at IBM, where he leads the planning and execution of complex projects and key initiatives within the IBM Software webMethods division. He has over 15 years of experience in the software industry, with a focus on Java, CI/CD, DevOps, and cloud-native technologies. Serafim is a passionate advocate for automation and is always looking for ways to improve the software development lifecycle. He loves learning new tech with a cold beer in hand and a smile on his face..
13:00-13:50
🍔 Lunch
Want to become a sponsor of our lunch break? Contact us.
13:50-14:20
🎤 Using React without using React
Hashtags: #React #VanillaJS #UIArchitecture #StateManagement #JavaScript
Suitable for: Frontend, Fullstack
In this talk, Krasi will explore how to apply the principles of React to build applications without using the React library itself. He will break down the core principles that power React: component-based architecture, declarative UI, and smart state management. Then, Krasi will show how you can apply them without importing React at all. Using vanilla JavaScript and lightweight alternatives, you’ll explore how to recreate the React mindset in any setup. Perfect for those who want to truly understand React's design patterns, use them outside the React ecosystem, and want to learn how to apply them in different contexts.

Krasimir Tsonev
💼 Senior engineer @ Trusti.bg
🚗 Varna, Bulgaria
Krasimir is a senior software engineer with a passion for JavaScript and front-end development. He is the author of several popular open-source libraries and a frequent speaker at international conferences. Krasimir is a strong advocate for simplicity and clarity in code and is always looking for ways to improve the developer experience. When he's not writing code, he enjoys spending time with his family and exploring the beautiful coastline of the Black Sea.
14:20-14:50
🎤 JS Signals (and Proxies)
Hashtags: #JavaScript #Signals #Reactivity #Proxies #StateManagement #WebStandards
Suitable for: Frontend, Fullstack, Architects
Signals are poised to redefine reactivity in JavaScript. Ilko will explore the new Signals API in JavaScript and how it can be used to build reactive user interfaces. He will compare Signals to other reactive programming techniques, such as Proxies and Observables, and discuss the pros and cons of each approach. Ilko will demonstrate how to build a fully reactive app using Signals, without relying on frameworks like React or Vue. We’ll also look at the evolution of signals in modern frameworks like SolidJS and the movement toward standardizing them across the JavaScript ecosystem. Expect clarity on where signals shine, where Proxies still win, and how the future of frontend state might look. The session will include a live coding demonstration of how to use Signals to build a simple reactive application.

Ilko Valchev
💼 IT Team Lead @ Enetpulse
📌 Sofia, Bulgaria
Ilko is an IT Team Lead at Enetpulse, where he manages the development of real-time sports data platforms. With deep roots in JavaScript and UI performance, Ilko is passionate about clean architecture and modern frontend patterns. He was a top-rated speaker at previous editions of DEV: Challenge Accepted, known for his engaging sessions and practical demos. Outside of work, he enjoys basketball, movies, and helping his team grow — ideally in that order.
14:50-15:10
🍺 Beer Break
Want to become a sponsor of our beer break? Contact us.
15:10-15:40
🎤 API testing journey through web protocols
Hashtags: #API #Testing #SecurityTesting #PerformanceTesting #Protocols #Automation
Suitable for: QA, Backend, DevOps, Fullstack, Security Engineers
In this talk, we will embark on a practical journey through the world of API testing, focusing on the various web protocols behind modern APIs — from HTTP and REST to GraphQL and WebSockets. Dawid will guide you through the essentials of API test automation, performance benchmarks, and security assessments. You’ll see live demos of popular API testing tools in action, with real-world techniques to validate and harden your APIs for production use. Dawid will bring insights from years of hands-on experience into a compact and actionable format.

Dawid Pacia
💼 Independent Consultant
✈️ Krakow, Poland
Dawid is a QA consultant with over 8 years of experience in the software industry, specializing in API, performance, and security testing. He’s an ISTQB-certified Test Manager, respected speaker at international conferences, and the author of a well-known blog on testing and QA. Passionate about quality at every level of the stack, Dawid brings clarity, energy, and real-world insight to every stage he joins.
15:40-16:10
🎤 Bug fixing in business - two frauds of almost half a million!
Hashtags: #FraudDetection #BusinessSecurity #Leadership #Ecommerce #RiskManagement
Suitable for: Everyone
In this gripping final talk, Vizo takes us through two jaw-dropping fraud cases that nearly cost his company almost half a million. As both a business leader and storyteller, Vizo will guide us through what actually happened, how internal loopholes were exploited, and what it took to recover from the blow. You’ll hear about tense moments with the police, refunding customers out of personal pockets, and learning the hard way how fragile trust can be. With charisma, humor, and brutal honesty, Vizo reminds us that in both tech and life, the real bugs are often human. A rare blend of drama, insight, and raw honesty from someone who’s been through it, and lived to tell the tale.

Velizar Velichkov
💼 COO & Partner @ 1ForFit
💼 Sales Director & Partner @ Grabo.bg
Co-Founder & Partner @ Artvent
📌 Sofia, Bulgaria
Velizar Velichkov - Vizo is a serial entrepreneur and the founder of several successful companies in the e-commerce and fitness industries. He has a deep understanding of the challenges and opportunities of running a business in the digital age. Velizar is a passionate advocate for entrepreneurship and a mentor to many young startups. As an actor who turned into business leader, he is combining creativity and business acumen in everything he does. Vizo is also a frequent speaker at business conferences and a regular contributor to leading business publications.
16:10-16:30
🍺 Beer Break
Want to become a sponsor of our beer break? Contact us.
16:30-17:00
⚡ Lightning Talks
5-min lightning talks, open for sign-up at the event.
17:00-17:30
17:30-18:00
🢀 Logout
Roadmap
Here is an approximate roadmap of important conference dates. Please note that some of these dates may change:
1 Jan
Event officially announced on the website
Call for speakers and sponsors opened.
Tickets on sale.
Tickets on sale.
15 May
Call for speakers closed.
15 Jun
Agenda announced
Nominations for Dev of the Year opened.
Early bug tickets sale ends.
Standard tickets on sale.
15 Aug
Call for sponsor ends
Nominations closed.
1 Sep
Standard ticket sale ends
Last minute tickets are on sale.
Voting for nominees starts.
20 Sep
Tickets sale ends
Last chance to buy a ticket.
28 Sep
DEV: Challenge Accepted 2025
The conference day.
Sponsors & Partners
Interested in sponsoring the event, or any other kind of partnership?
Write to us at or call +359887675786 for more information.