How to Build a CRM as a Solo Developer

What You're Building

A CRM (Customer Relationship Management) tool helps businesses track their interactions with customers and manage their sales pipeline. Salesforce dominates the enterprise space, HubSpot owns the mid-market, and there are dozens of smaller players. So why would a solo developer build a CRM?

Because Salesforce is a nightmare to use, HubSpot is expensive once you actually need it, and most small businesses just want a simple way to track leads and deals without a PhD in CRM configuration. I've seen solopreneurs and small agencies using spreadsheets because every CRM they tried was overkill. That's your market.

Difficulty & Timeline

Recommended Tech Stack

Next.js for the frontend dashboard. CRMs are data-heavy applications with lots of tables, filters, and detail views. React's ecosystem handles this well. Use a component library like shadcn/ui for consistent, professional UI components.

Django or Node.js for the backend. Django's admin panel is actually useful here as an internal tool for managing data. PostgreSQL is the database, obviously. CRM data is inherently relational: contacts belong to companies, deals have stages, activities link to contacts.

For email integration, use the Gmail or Outlook APIs so users can see email threads alongside their contact records. This is a killer feature that separates a real CRM from a glorified spreadsheet.

Step-by-Step Plan

Phase 1: Contact & Deal Management (Week 1-4)

Build the contact database first. Name, email, phone, company, notes, custom fields. Add a company/organization layer so contacts can be grouped. Build a solid table view with search, filters, sorting, and pagination.

Then build the deal pipeline. A Kanban board where deals flow through stages (Lead, Qualified, Proposal, Negotiation, Closed Won, Closed Lost). Each deal links to a contact and has a value, close date, and probability. Users drag deals between stages.

This core loop (contacts + deals + pipeline) is the minimum viable CRM. Get it right before adding anything else.

Phase 2: Activities & Communication (Week 4-7)

Add activity tracking. Calls, emails, meetings, notes. Users log interactions with contacts and see a chronological activity timeline on each contact's profile page. This timeline is the most-used feature in any CRM because it answers the question "What happened with this client?"

Build email integration if possible. Connecting to Gmail or Outlook so emails automatically appear in the contact timeline is incredibly powerful. It turns your CRM from a manual data entry tool into something that actually stays up to date.

Add task reminders. "Follow up with John next Tuesday" type reminders that show in a daily view. Sales teams live and die by follow-ups, and automated reminders ensure nothing falls through the cracks.

Phase 3: Reporting & Polish (Week 7-10)

Build a dashboard with key metrics. Total deals in pipeline, total value, conversion rate by stage, deals won this month, average deal size. These numbers help users understand their sales performance at a glance.

Add basic reporting. Revenue forecast based on deal probability, sales activity report (calls made, emails sent), pipeline velocity (how fast deals move through stages). Don't build a complex BI tool. Simple charts and tables that answer common sales questions.

Set up billing, import/export (CSV is essential), and build a landing page that speaks directly to your target niche.

Key Features to Build First

Contact database with search and filters. The core data layer. Must be fast, searchable, and support custom fields.

Deal pipeline (Kanban). Visual pipeline where deals flow through stages. Drag and drop between stages.

Activity timeline. Chronological log of all interactions on each contact. Calls, emails, meetings, notes.

Task reminders. Follow-up reminders that keep deals moving. Daily task view showing what needs attention today.

CSV import/export. Users need to get their data in and out. Import from spreadsheets, export for reports or migration. This is table stakes.

Architecture Overview

Dashboard (Next.js)
  ├── Contact list & detail views
  ├── Deal pipeline (Kanban)
  ├── Activity timeline
  ├── Task/reminder management
  ├── Reports & dashboard
  └── Settings & team management

Backend (Django / Node.js)
  ├── Contact/Company CRUD
  ├── Deal pipeline management
  ├── Activity logging
  ├── Task & reminder scheduler
  ├── Email integration (Gmail/Outlook API)
  ├── CSV import/export
  ├── Reporting engine
  └── Billing (Stripe)

Storage
  ├── PostgreSQL (contacts, deals, activities)
  ├── Redis (caching, background jobs)
  └── S3/R2 (file attachments, email attachments)

Common Pitfalls

Building for enterprise. Enterprise CRM is Salesforce's game, and they have 73,000 employees working on it. You will not win there. Build for freelancers, solo consultants, small agencies, or a specific industry vertical. These users want simplicity and will pay for it.

Over-engineering custom fields. Users will want custom fields. That's fine. But don't build a full custom field engine with custom field types, validation rules, and calculated fields for v1. Start with a few text and dropdown custom fields. Expand based on actual demand.

Ignoring data import. The first thing any CRM user does is import their existing contacts. If your CSV import is buggy, slow, or confusing, you lose them immediately. Invest real time in a solid import flow with mapping, duplicate detection, and error handling.

No mobile access. Sales people work on their phones constantly. Before meetings, between meetings, at events. Your CRM needs to be usable on mobile. Not necessarily a native app, but a responsive web interface that works well on phones.

Trying to replace email. CRM tools that try to become your email client never work well. Instead, integrate with existing email (Gmail, Outlook) and pull relevant conversations into the contact timeline. Work with email, don't replace it.

Timeline Estimate

Is This Worth Building?

Yes, with a massive caveat: pick a niche. "CRM for everyone" is suicide. "CRM for freelance designers" or "CRM for real estate agents" or "CRM for recruiting agencies" is viable. Each niche has specific workflows, terminology, and pain points that generic CRMs handle poorly.

The revenue potential is strong. Per-user pricing means revenue grows with team size. Even at $15/user/month, a 5-person team pays $75/month. Get 200 teams and that's $180k/year. The stickiness is excellent too because migrating CRM data is painful, which means low churn once teams are set up and using it. Just make sure you're building for people who are currently frustrated with their existing solution, not trying to convince spreadsheet users that they need a CRM.