Making integration simple: just don’t delete it

In this series of short blog posts, we’ll try to break down some of the engineering principles behind integrations. We’ll use examples from Seamless, but the principles will be universal.

What happens if we delete records in one of the systems in the sync?

Well, you might not like the answer – but the best answer is that in day-to-day operations you probably shouldn’t be deleting records at all. (Cough cough GDPR … I know, we’ll get there).

In this post we’ll look at what it means to delete a record and then we’ll consider what that means for an integration.

Deleting records

Let’s talk about deletion in principle before we talk about integration.

In most systems, a record, let’s say a Contact record, will have connections to a handful (or many more) other records. A Contact might belong to a Company, they may be referred to on Orders, on Help Desk Tickets, on Sales Opportunties, etc. In database terms, each of these are relations between records. In the olden days as far back as the 1990’s, we talked about “relational databases” for this very reason.

Deleting just one Contact record could have a significant knock-on effect. What happens to all those other records referring to that Contact record? The answer is very system specific, we were looking at this recently for a sync between Freshdesk and Dynamics 365.

  • Freshdesk will delete the Contact and all associated Tickets. That has a significant implication on reporting and, in the case of a helpdesk system, trying to identify systemic problems which are causing multiple tickets to be raised.
  • Dynamics would leave the Tickets in situ but delete the reference to the Contact.

Ultimately, each system will have a different approach to this. In some cases it will be elegant (Dynamics), in some cases efficient (Freshdesk) and in some cases, the system just won’t have the ability to delete.

One term sometimes bandied about is a soft delete. This is more like an archiving status: the record still exists, it is just not visible to all users. This can solve the relational issues, but might have UI/expectations challenges to manage.

Okay, so deleting is not great, let’s talk about integrations

Let’s talk about deletions in the context of a Seamless integration. Seamless is architected as a message queue, it polls a source system for new/changed data and transmits it to a target system. Seamless doesn’t actually know about the data itself or maintain a list of all records on each system. It was designed this way for a range of security and flexibility reasons.

The challenge of this approach is that Seamless cannot know about records that no longer exist. When polling the source system, a record that no longer exists doesn’t appear as changed because it doesn’t appear. It is a classic “Donald Rumsfield scenario” of unknown unknowns.

Simply put, if you delete a record from a source system, Seamless will never know.

You’re smart guys, you can fix this

Of course, it it is possible to engineer a solution. As always, there are options.

  • Option one: A register of records. In this option Seamless would maintain a register of records in each system. We can do this by record id so there’s no content stored inside Seamless and this would address the pressing security consideration.
  • Option two: Flag for deletion. In this option, we would add a flag to the record in either/both systems titled “Flag for deletion” or similar. As this flag is effectively a change to an existing record, Seamless will recognise the flag and act accordingly. This could be deleting the record in both systems and cleaning up references as required.

Flagging for deletion can be achieved in config and gives Seamless flexibility to clean-up records as required by either system in the sync. To date, this is the option that has been preferred when the question is raised.

Sometimes you just gotta delete

There are can be legitimate drivers for deleting records. A request from an individual to delete all records on hand is one such example. Under the GDPR, this is something all businesses operating in Europe should be considering. SaaS app vendors will increasingly find this is a requirement but, given Seamless’ ability to connect to all sorts of endpoints (not just modern SaaS apps), we need to ensure we have a few tricks up our sleeve.

In this context, there are a few options (always with the options!). We could implement a deleting mechanism along the lines of those described above. Or we could consider data anonymisation.

If a system doesn’t have an elegant way to clean up relationships between records, it might be better to anonymise data rather than delete it. This could be done by changing names (and other personal info) to random strings. This is certainly something that could be done with Seamless’ data transform features.

So, what happens when someone deletes a record?

That very much depends what you mean by “delete”. Is it a hard delete where the record disappears? Is it a soft delete where the record is archived? Does the system have a way of telling us the record has been deleted or do we need to construct a way of doing this?

As always, there are options.

Making integration simple: syncing all over the world

In this series of short blog posts, we’ll try to break down some of the engineering principles behind integrations. We’ll use examples from Seamless, but the principles will be universal.

Azure regions

One of the most powerful lines in all of the Seamless sales materials reads “Seamless can be deployed within an Azure region of your choice.” It seems so straightforward, but it provides really meaningful options for Recursyv and for Seamless users.

Let’s start with the basics: What is an Azure region?

Azure is the cloud computing environment provided by Microsoft. In practical terms, this means that when Recursyv operate Seamless, we’re actually running our code inside a Microsoft provided computing environment which, in physical terms, is hosted inside a Microsoft data centre.

An Azure region describes a set of data centres which are all connected with high-speed data lines. Typically an Azure region is aligned to a geographic region that you may recognise, within a single country or across a group of closely located countries. Over time, Microsoft continue to open more regions – most recently South Africa and the Middle East.

Using multiple data centres within a single region provides redundancy. If Data Centre A becomes unavailable, all services being run within Data Centre A can be switched over to Data Centre B. Ideally this will happen without users noticing a service interruption.

For security reasons, Microsoft typically won’t detail the specific location of any given data centre, except to confirm that if you subscribe to Azure services within a specific Azure region, the data centres will be located within that region.

Azure region size

At the time of writing this post (August 2019), Azure was available in 54 regions servicing 140 countries.

Okay, it’s about geography – but why does it matter?

There are two main reasons why it matters.

(1) Connectivity speed

If we’re syncing between two applications hosted on the West Coast of the USA but using Seamless within the UK, we’d be sending data across the continental USA and across the Atlantic to a UK data centre, performing Seamless core operations and then returning the data back across the Atlantic and back across the continental USA. This will have a significant time delay and, if you’re counting, unnecessary energy consumption. For two applications hosted on the West coast of the USA, we’d be wise to use an Azure region on the West coast of the USA.

Of course, we won’t always be syncing two applications hosted in the same place. In these scenarios, we’ll use data location as one of the considerations when advising customers where Seamless should be hosted.

(2) Relevant legislation

Arguably more important than data transfer speeds is the legislation/regulation that will apply to the Seamless user’s processing of data. There is a growing recognition of the importance of data housing commitments and associated legislation to support these. Within the EU, the GDPR (General Data Protection Regulation) is the most widely known such example.

Seamless users will typically have significant legislative commitments to look after the data that is being synced by Seamless. Choosing the appropriate data region will enable Seamless users to meet their commitments to their own customers/suppliers/partners.

Is it all as complicated as it sounds?

No. In most cases Recursyv will be able to provide advice on how to select the most appropriate Azure region. This will largely be driven by factors detailed here as well as some operational considerations which will be specific to the given integration.

At the time of writing, Recursyv are operating Seamless in the Azure regions in the UK, EU, USA and Australia with an implementation in Azure Germany being planned. In each case, the Seamless services are deployed within the Azure region in support of providing a mix of the appropriate connectivity speed and the most suitable legislative environment.

Making integration simple: all about API calls

In this series of short blog posts, we’ll try to break down some of the engineering principles behind integrations. We’ll use examples from Seamless, but the principles will be universal.

API Calls

What is an API call?

Let’s start with an API and then describe an API call.


An API, application programming interface, is the “public face” of one software application to other applications. One app, Seamless, can reach out to another app, let’s say Autotask, and ask the other app for something. Seamless could be asking Autotask for data, Seamless could be trying to update a record in Autotask, etc.

Typically SaaS vendors publish API guidelines which describe the various things that an external system can ask the application to do. As long as Seamless reaches out to Autotask and asks according to the structures laid out in the Autotask API Reference, Autotask should do what Seamless asks.

An API call

An API call is one instance of Seamless asking Autotask to do something. If Seamless asks Autotask for a Contact record where the Contact ID = 123454, that query is a single API call.

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