Mixed-Tenant Architecture for SaaS ERP to Guarantee Security & Autonomy for 200+ B2B Clients

Data leakage risk and the lack of autonomy for each B2B end user

The Client focused on the digital transformation of car service bodyshops, all of that used a mix of .xls files and papers. For that, the business owner decided to create a custom ERP to automate the manual and time-consuming key business workflows.

However, as the Client wanted to sell its solution to multiple separate businesses, it became critical to build a system that keeps data autonomously and allows managing it securely and independently for each B2B client. 

The successful deployment of such a request implies choosing the right architecture for the product, which in this case has turned into an important commercial decision going far beyond a purely technical aspect. 

No in-house specialists with the right skill set to build a custom ERP with mixed-tenant architecture

As any startup, they couldn’t risk employing a big team internally, so they needed a good technology partner to rely on, with hands-on expertise in building a custom ERP.

Outsourcing the ERP development with mixed-tenant architecture to the experienced team

One of the partners of the Client had a positive experience working with Belitsoft. So our company was selected based on this reference, as well as considering our approach to development, and a large talent pool to draw from.

By outsourcing custom software development to Belitsoft, the company with an extensive pool of specialists, the Client has got the following benefits:

• Quick start. Involving an experienced developer into the project from our talent pool without wasting time on hiring allowed the Client to launch the MVP in just 3 months, get the first customers and start earning;
• On-demand team scaling. Not keeping extra developers in the team let the Client save the budget. At the same time, the Client quickly received the necessary workforce on demand from our 300+ developers.

All in all, the development team has grown from 1 to 9 people when the project required it, then scaled down correspondingly to save the Client’s budget.

Ensuring data security and autonomy for different end users by choosing mixed-tenant architecture

Belitsoft’s team has developed a custom ERP for repair service with the following unique features:

1. Both ERP and CRM functions. The software has the functions of an ERP system for managing the workforce and financial resources and a CRM system for managing customers.
2. SaaS model. End customers (automotive repair shops) pay a fixed amount for using the platform without having to install additional software. All rights of the software belong to the owner of the platform and the appropriate data inside the platform – to their customers.
3. Mobile applications as an add-on for managers and repair technicians. The iOS and Android apps allow tracking time, scan receipts and pass them on to the accounting software, take photos of the damage and send them to media storage.

Choosing the most beneficial and suitable deployment architecture for the Client’s SaaS solution requires considering a variety of business aspects. 

To avoid wrong architectural decisions leading to hard-to-manage operational gaps, our specialists started by evaluating the estimated workload, resource usage, security, tiered pricing model, software usage patterns, and consumption rates.

Even though building a multi-tenant ERP may be cheaper and easier to manage, it was neglected due to the high importance of separating the databases of end B2B clients and keeping a high level of security and independence for each of them.

Based on the analysis of business needs, our development team offered the mixed-tenancy model, in which a single instance of software serves multiple tenants or clients' organizations. 

When a new tenant appears, the Client creates a new separate database for a new tenant on the web server. The tenant has its own data and can customize features or configurations while sharing the same underlying infrastructure and codebase.

It allows the Client to sell its ERP solution to car service owners for managing their automobile repair shops while 

• keeping data on separate databases for each repair shop, 
• letting independent customization on individual demand of end users,
• ensuring a high level of security for the business and customers' data,
• avoiding the “noisy neighbor problem” when one of the bodyshops sends multiple requests to the ERP, the other bodyshops avoid overloads thanks to using separate databases.

An extra benefit of the mixed-tenant architecture is the ability to deliver releases to different tenants with diverse velocities. When our Client delivers a release to a small car dealer, usually, they prioritize getting new functionality and updates at the soonest, sometimes even before eliminating minor bugs. While for large dealers, it's essential to get only the functionality after it´s been double-checked. Mixed-tenancy architecture is the only one that allows such an individualized approach.

Tech Stack

Backend: .NET CORE

Database: MySQL, Elasticsearch 

Frontend: Vue.js

The selected tech stack allowed our team to make the ERP development cost-effective and to gather a development team and start developing in the shortest possible period of time. 

Step-by-step creation of mixed-tenancy architecture

To build an app with mixed-tenancy architecture, our developers’ goal was to design the ERP to support multiple tenants and to securely isolate the data and configurations for each tenant. For that, Belitsoft’s developers had to

1. Identify the common features and functionality that will be shared by all tenants, and design these as part of the core system.
2. Determine the features or configurations that may vary from tenant to tenant, and enable the ERP to support customization or configuration at the tenant level.
3. Implement security measures to isolate the data and configurations for each tenant, such as using separate databases or namespace prefixes to store tenant data.
4. Use a multi-tenant database schema to store tenant-specific data, such as separate tables or schema for each tenant.
5. Test the ERP thoroughly to ensure that it is stable and secure and that it correctly handles the separation of data and configurations for each tenant.

Using Time & Material and Agile to deliver results fast and within a budget 

It has been agreed to use Time & Materials model in combination with the Agile methodology. It allows our Client to take full control of the development process, and change or add new requirements when needed.

We have 1-week sprints. Every week our team receives emails with an extensive tasks list, detailed instructions given individually to each developer, and additional information about new adjustments. Additionally, we arrange a call with the Client for discussing and prioritizing upcoming tasks, estimating the required time, and agreeing on other aspects when needed.

Our team has changed their working hours to adapt to the Client’s time zone with 3 working overlapping hours daily. This lets us be regularly in touch with the Client and make requested changes on very short notice. 

The project is fully managed by the Client, who uses Jira for task tracking, which helps the Client stay informed at every step.

Belitsoft's developers have successfully delivered a business-oriented and scalable ERP with highly secure and autonomous mixed-tenant architecture. It is ideal both for software providers selling their ERPs to businesses and large car service centers with subdivisions in different locations that want to keep a high level of security among their divisions. Their processes are fully independent, their databases are autonomous, and their loads don’t affect others.

Nowadays, this platform is widely used by 200+ B2B customers working independently and securely, and having the possibility to get customization as the result of the right choice of architecture.

We were able to build a high level of trust and communication with the business owner and key people from the company, which helped us to achieve our aims fast maintaining high quality.

Belitsoft is continuing to perform maintenance and improvements of this custom ERP with mixed-tenant architecture.