London MUG: Migration of Legacy Systems To MongoDB

London MUG: Migration of Legacy Systems To MongoDB

Join us for an insightful evening at the London MongoDB User Group meetup on November 30th, hosted at Metro Bank. Our featured speaker, John Sewell, a seasoned consultant with over 25 years of experience in the IT sector, will take us through the fascinating journey of migrating multiple legacy insurance systems for a large European insurance company to MongoDB Atlas.


:arrow_right: To RSVP - Please click on the “ ✓ RSVP ” link at the top of this event page if you plan to attend. The link should change to a green button once you RSVP. You need to be signed in to access the button. Have You can also register for this event on our London MongoDB User Group Meetup Page.


  • Introduction (30 min): Networking and refreshments.
  • Talk 1 Presentation (30 min): “Migration of Legacy Systems To MongoDB” by John Sewell
    • An overview of the process of moving legacy systems.
    • Insights into migrating a large European insurance company’s systems to MongoDB Atlas.
    • Designing a new interface to handle data and reporting requirements.
    • Real-world examples and challenges faced during the integration process.
    • Q&A session with the audience.
  • Talk 2 To be Announced (30 min)
  • Trivia, Fun, Networking and a chance to win some swags!


Event Type: In-Person
Location: Metro Bank 1 Southampton Row, Holobarn · London



John Sewell

Experience: 10+ years in Digital Consultancy Services
Bio: John is a consultant with a rich background, having worked across diverse industries such as recruitment, ship management, buy-side order and exception management, local government, and insurance. With over two decades of experience, he brings a wealth of knowledge to the table.



Sani Yusuf

Founder, Haibrid

1 Like

Registered and look forward to see you there!

A topic that I’d particularly like to be discussed is, any tools to drive the migration in an architecturally sustainable way. We know that from RDBMS to MongoDB is not a lift and shift, it involves design pattern changes, but not all developers are educated this way. They might still insist on 3NF and rely heavily on joins, and just abuse $lookup.


Marcus, we’ve probably had it a bit easy in regards to those issues, in that we’re decommissioning the old systems and effectively archiving the whole system.
Part of the new system does accept new data but we effectively have no lookup tables to join over, in fact as far as I’m aware we don’t use $lookup anywhere. The data is completely de-normalised (ish) when we store it.

We do have lookups into existing data when processing new data, but that can be a touch involved, I’m happy to go through what we’ve done.

If you want to dig into more detail (than I present) we could have a catchup at the meet.

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Hello everyone,

I regret to inform you that due to unforeseen circumstances, we have to postpone the event. We are currently planning to reschedule it for January 25th and will keep you updated with any further developments.

We apologize for any inconvenience this may have caused, especially if you have already made plans. We hope to see you soon after the holidays and appreciate your understanding in this matter.

Best regards,

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