The story begins — I used to work as a Data Engineer at one of the largest e-commerce companies in Vietnam, building large-scale data systems and marketing tools such as attribution platforms, performance dashboards, CDPs, and affiliate systems. However, the closer I got to the marketing team, the more I realized a significant gap: we can measure CAC, ROAS, and attribution all day long… but when it comes to retention, many businesses are still pouring money in a reckless manner.

From my practical perspective, there are two ways to bring orders back to the business:

 The Ad Trap

Continuously finding new customers through advertising. This is a very powerful method, but CAC is volatile, attribution is complex, and you can never be sure if CLV (Customer Lifetime Value) is really breaking even.

 The Data Goldmine

Bringing old customers back. This is a lever that is often underestimated because the business already has first-party data — purchase history, behavioral signals, and customer cohorts.

Why did I build Nudgen?

Most teams want to run win-back campaigns, but they often fall into the familiar trap of: sending bulk emails, generic content that sounds robotic, and it easily ends up in spam.

I created Nudgen to leverage data engineering experience into the retention problem.

From a technical standpoint, it makes this process easier:

• Custom Brand Voice: You define the goals and tone of the brand — from professional to fun — so that each "nudge" is aligned with the brand image you are building.

• LLM-Powered Personalization: Use LLM to create personalized and in-depth email subject lines and content.

• Event-Driven Auto-Stop: This is the most critical part. Nudgen tracks interaction events; as soon as the user returns or clicks a link in the email, the email sequence will automatically stop. No more "zombie" spam emails sent to your actual customers.

• Engineering-Grade Infrastructure: The system protects rate limits by batch when sending emails, encrypts PII when stored, and automatically handles bounce/unsubscribe.

Moreover, an effective retention strategy often involves not just sending a single email, but building a Drip Campaign — a series of emails designed in a sequence to gradually bring users back.

Simple example:

Day 3 after abandonment → A gentle email reminding of the product value or useful content
Day 7 → Suggest related products or content based on previous behavior
Day 14 → A small incentive to encourage return
Day 30 → The final win-back email with a stronger message

The crucial point is not just the sequence, but the timing and context.

With Nudgen, these Drip Campaigns are built based on events and actual user behavior data. And most importantly: the email sequence will automatically stop as soon as the user returns or engages, avoiding redundant or annoying emails.

The goal is not to send more emails — but to send the right emails, at the right time, to the right people.