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We are happy to announce the availability of event-driven Functions for customers on Amazon Web Services (AWS). Extend our cloud banking platform with custom business logic to fit your unique needs.

In addition to previously released core extensions, we have now released event-driven Functions which integrate with our Streaming API and allow you to leverage any event happening in the core to build flows that truly work for you to fit your unique needs.

Read on to learn more about key features, use cases and how to set up your first Function today!

Why use Mambu Functions?

Mambu Functions allows our customers to extend the functionality of our cloud banking platform like never before. Functions utilise the code running in your preferred programming language (Javascript or Typescript) in a separate, dedicated, and secure compute environment to substitute pre-existing processes in our core with your own logic.

At their core, Functions allow you to take your core configuration to the next level by enabling complex business logic to be run that was previously not possible. You can focus on building innovative offerings, while real-time responsiveness, scalability, security, and compliance with regulatory standards are guaranteed on the back-end. Functions can:

  • Provide a native solution to extend our core banking system, through extension points within our core or based on events happening in the Mambu system by leveraging our existing notifications service
  • Provide the ability to call internal Mambu APIs and public APIs
  • Provide secret management and basic orchestration capabilities

Who are Mambu Functions for?

Any Mambu customer, including established banks, neobanks, and fintechs, can leverage event-driven Functions, they will be beneficial for you if you:

  • Need simple orchestration capabilities and do not have or want to manage your own orchestration solution or tap into complex third-party solutions;
  • Have a small development team that can write and manage code using JavaScript or TypeScript;
  • Do not need to retain the current state or store transactions. The system can be designed in such a way that if any transaction encounters an issue, it can be retried without relying on the storage of interim results.

Please note that Functions incur an additional cost and are only available for customers on Amazon Web Services (AWS) at the time of launch. Event streaming also needs to be enabled for event-driven Functions. For updated availability timelines on additional clouds and feature enabling, please reach out to your Customer Success Manager.

Key Functions features and capabilities

  • An intuitive developer experience that makes custom configurations effortless and efficient. Developers are empowered with an intuitive Command Line Interface (CLI) to manage Functions including one click deployment and native support for TypeScript and JavaScript.
  • Top-notch code quality: robust support for CI/CD, expedited debugging, and unit & integration tests to ensure your functions run seamlessly.
  • A serverless trusted infrastructure: fully-managed hosting, security, scalability, and maintenance mean faster development and better performance. Functions come with built-in security features, providing you with peace of mind on the security of your functions and data.
  • High availability, maximum performance: Built-in redundancy and failover mechanisms ensure high availability. They are also optimised for performance and resource utilisation. The underlying infrastructure is continuously monitored and fine-tuned to ensure optimal performance and minimise latency, providing customers with a smooth and responsive experience.
  • Ready for scale: Functions offer automatic scaling on demand. Resources are dynamically allocated to handle fluctuations in workload without requiring any intervention. This ensures that Functions can handle varying levels of traffic efficiently.

New production-ready use cases with event-driven Functions

Although there are numerous use cases and scenarios where Functions can be beneficial for you, we'll offer a few examples here. It's important to note that these examples are not exhaustive. For tailored assistance and to discuss specific requirements, Mambu customers can reach out to their dedicated CSM.


Calculate transaction fees asynchronously

For every transaction, a Function can perform an authorisation to check if the account has enough balance for both the transaction amount and the fees amount. The transaction will only happen if the full balance is present to avoid accounts going into technical overdraft.

Activate deposit accounts without creating financial transactions

For newly created accounts, once the required know your customer (KYC) verification is complete, you can now leverage Functions to seamlessly activate the account without having end users make an initial deposit or transfer transaction. This can also be used to manually activate dormant accounts without posting a transaction.

Term deposit break fee

In the context of term deposits, break fees are standard practice when a withdrawal occurs before the specified term end date. The break fee is determined by various factors, including the custom field percentage in the term deposit account, the withdrawn amount, and the number of calendar days between the activation and transaction dates. While some details are readily available during the withdrawal event, obtaining the activation date requires an additional API call. Leveraging event-driven Mambu Functions can streamline this process, ensuring the efficient calculation of term deposit break fees by seamlessly integrating information from different sources, resulting in a faster and more accurate calculation in the event of a withdrawal.

IBAN Generation

When a new account is created, using Functions, it is now possible to generate the International Bank Account Number (IBAN) which consists of a two-letter country code, followed by two check digits, and up to thirty-five alphanumeric characters and automatically store it as a custom field in the Mambu core without manual intervention.


Adjust late interest balance for non-performing loans

When borrowers fail to pay instalments on time, lenders may charge the outstanding principal balances interest rates higher than the default rates of loans. Prior to the due date, Mambu will trigger the required data attributes so that Functions can calculate the new late interest balance for the outstanding principal & seamlessly adjust the relevant applied interest.

Apply a custom one-time fee when a loan goes into arrears

When an account’s status changes to “In Arrears”, Functions can be used to apply a penalty fee after the arrears and penalty tolerance period has passed. The custom fee is calculated after the due date based on the loan amount and applied automatically.

Do you have a specific use case in mind? Reach out to see if Mambu Functions can help you.

Set up your first Function today

In order to set up an event-driven function, you need to:

  • Create an event streaming notification template for the target event via your Mambu UI,
  • Generate a sample function using the Mambu CLI and then implement the custom business logic,
  • Create secrets necessary for your functions,
  • Build and deploy the function,
  • Create a function subscription for the target event,
  • Monitor your function to verify that events are being processed as expected.

Head over to our documentation for a detailed guide on how you can easily get started with Mambu Functions.

In short

Far simpler and swifter than setting up external third-party orchestration tools, Mambu Functions can be a great way to inject your complex business logic into the Mambu Platform. We keep things secure and scalable for you while you focus on all the exciting use cases you can implement.

If you would like to request access, please get in touch with your Customer Success Manager to discuss your requirements. Not yet a Mambu customer? Get started today.

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Omar Paul
Omar is the SVP Product at Mambu and is an accomplished product executive known for driving business growth and leading successful organisations in the technology industry, including most recently at Amazon.
Omar Paul