At Elixir Meetup #1, Krzysztof Kempiński discussed the reliability of Elixir and Erlang, emphasizing their robustness and suitability for building dependable applications.

Table of contents

    His presentation covered the history, key features, and practical advantages of using these languages in modern development.

    About Krzysztof Kempiński

    Krzysztof Kempiński is a seasoned IT professional with over 16 years of experience. He has held various roles, including developer, team leader, CTO, and co-owner of a software house. Krzysztof is also the host of the podcast "Let's talk about IT."

    The Foundation of Reliability

    Telecommunication Roots

    Krzysztof began by explaining the origins of Erlang in the 1980s at Ericsson. Designed for telecommunications, Erlang had to meet stringent reliability and concurrency requirements. This legacy is one reason why Erlang and its descendant, Elixir, are so reliable.

    Key Points:

    Designed for Telecom: High reliability and concurrency. Open Source: Released by Ericsson to benefit the broader community.

    Features That Ensure Reliability

    Functional Programming and Immutability

    Functional programming and immutability are core features that contribute to the reliability of Elixir and Erlang. These features help avoid common pitfalls in concurrent programming.


    Predictability: Pure functions ensure consistent outputs. Ease of Debugging: No side effects simplify debugging. Concurrency: Safe and efficient handling of concurrent processes.

    Lightweight Processes and Actor Model

    Efficient Concurrency

    Krzysztof highlighted the efficiency of Erlang's lightweight processes, which consume minimal resources compared to traditional OS processes. The Actor Model, used for managing these processes, further enhances reliability by isolating state and communication.

    Key Techniques:

    Lightweight Processes: Efficient and scalable. Actor Model: Isolated state and message passing.

    Supervision Trees

    Self-Healing Systems

    Supervision trees in Erlang and Elixir ensure that applications can recover from failures. Supervisors monitor processes and can restart them if they fail, maintaining system stability.

    Key Features:

    Supervisors: Monitor and restart failing processes. Fault Tolerance: Ensures minimal downtime and high availability.

    Hot Code Swapping

    ###Seamless Upgrades One of the standout features of Erlang and Elixir is hot code swapping, which allows updates to be applied without stopping the system. This feature is crucial for maintaining uptime in production environments.


    Continuous Operation: Apply updates without downtime. State Preservation: Maintain system state across updates.

    Real-World Examples

    Erlang in Production

    Krzysztof shared examples of Erlang in production, including a telecommunication switch that ran for 20 years with only 0.6 seconds of downtime and WhatsApp, which managed 900 million users with just 50 engineers.

    Notable Uses:

    WhatsApp: Highly efficient and reliable messaging service. Telecom Switches: Exceptional uptime and reliability.

    Practical Applications

    Adopting Elixir and Erlang

    Krzysztof encouraged developers to adopt Elixir and Erlang by experimenting with their features and integrating them into their projects. He emphasized the ease of getting started and the long-term benefits of reliability and performance.


    Krzysztof Kempiński’s presentation at Elixir Meetup #1 provided a comprehensive overview of the reliability features of Elixir and Erlang. By leveraging these features, developers can build robust, scalable, and maintainable applications.

    Join the Community

    Ready to explore the reliability of Elixir and Erlang?

    Register for the next Elixir Meetup at Curiosum Meetups: Registration Join our community of Elixir enthusiasts at Elixir LinkedIn Group Prefer watching the presentation? Here’s the video

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