Custom CRM and ERP development

Build, buy or extend: which CRM option fits?

Most SMEs should start with a standard CRM such as HubSpot, Pipedrive, Salesforce or Microsoft Dynamics 365 and adapt it. A custom CRM or ERP pays off when your process is itself a competitive advantage, when many people need one narrow view but would each need a license, when core data has to stay where you control it, or when most of the work is integration with systems a standard CRM can’t reach. Sensaria doesn’t resell CRM licenses, so the recommendation follows your process.

Option	Fits when	Watch out for
Standard CRM, configured	Your sales process is close to what the product assumes	Workarounds in notes fields; license cost growing with the team
Existing CRM, extended	The CRM works but lacks data from other systems	API limits and plan tiers that gate custom objects
Custom CRM or ERP	The process is specific, integration-heavy, or data location matters	You own maintenance and further development
Hybrid	Standard CRM for sales, custom application for operations	One owning system per shared field

The comparison continues in custom vs off-the-shelf software.

How we build a CRM or ERP

Data model before screens. We define the entities (companies, contacts, deals, orders, products, tasks), their identifiers and the matching rules first. Normalized email addresses and company domains are the usual keys for deduplication, and every merge is recorded in an audit trail, so a wrong match can be traced.

Pipelines as configuration. Stages, required fields per stage, follow-up windows and assignment rules live in settings, not in code, so sales management can change them without a release.

Roles enforced in the backend. A salesperson sees their accounts, a manager sees the team, finance sees the invoicing fields. Hiding a button in the interface is not access control.

Automation that respects people. Automated steps create tasks, send reminders and move statuses, and each action is logged. When a person overrides an automated decision, the person wins. In one system we built, AI classifies incoming replies, and a manager’s manual label always takes precedence.

Integrations read-only by default. Syncs from other platforms start read-only, run incrementally with cursors and are safe to repeat. Writing back is added deliberately, field by field.

What goes wrong in CRM and ERP projects

• Migrating the mess. Importing old data as it is brings duplicates and dead records into the new system. We run a dry-run import with a validation and deduplication report before cut-over.
• Too many required fields. Salespeople stop logging activity. Fields become required at the stage where they matter, not when a record is created.
• The same metric computed three ways. Sales, marketing and finance each calculate conversion differently. We define each metric once in the data layer and reuse it in every report.
• Integrations that overwrite good data. Two systems editing the same field produce silent conflicts. Every shared field gets exactly one owning system.

What drives cost and timeline

Driver	Effect on effort
Entities and workflows	Each object type and approval path adds model, screens and tests.
Users and roles	Fine-grained permissions add design and testing work.
Data migration	Volume and quality of existing data often decide the go-live date.
Integrations	Accounting, e-banking, shop and email platform APIs vary widely in quality.
Reporting	Custom reports and exports for finance and management add scope.
Mobile or field use	Teams on the road need a different interface and sync logic.

When you compare against a SaaS CRM, look at several years: licenses per user, implementation, integrations and internal admin time on one side; build, hosting, maintenance and further development on the other. After discovery we send a fixed-price proposal for a first release or a phased plan.

Customer data, the FADP and the GDPR

A CRM is mostly personal data, so data protection law affects its design. For data processed in Switzerland that is the revised Federal Act on Data Protection (FADP), in force since 1 September 2023; for people in the EU it is the GDPR. Under the FADP, people can ask what you hold about them (Art. 25), so we build a per-person export. Retention periods and deletion are part of the system rather than a yearly manual clean-up. Processors such as hosting and email platforms are documented, and breaches likely to cause a high risk must be reported to the FDPIC (Art. 24). Under the FADP, companies with 250 or more employees must also keep a record of processing activities; smaller ones only if they process sensitive data on a large scale or run high-risk profiling. Hosting is in Switzerland or an EU region, agreed with you.

How it connects to the rest of your system

A CRM is only as good as the data that flows into it. Leads arrive from your website. Follow-ups run through CRM and sales automation and email automation. Orders, invoices and payments move through API integrations. The whole chain is described under sales automation.

Why Sensaria

We have built systems that work next to a CRM and feed it. A startup discovery and outreach platform pushes positive replies into the client’s CRM over its REST API. An affiliate reactivation system syncs read-only from a tracking platform and turns replies into manager tasks. An affiliate recruitment engine resolves identities across email, domain and social profiles, with an audit trail for every merge. We have also built a WooCommerce integration that turns new orders into CRM deals. Sensaria AG is based in Lugano, Switzerland, and works with companies in Switzerland and abroad in English, Italian, German and French.