Rule-Based Matchmaking In a Networking Event

Imagine you are organising a virtual networking event where attendees join a series of 1:1 video calls with different people.

In most cases, participants can be matched randomly. But sometimes, you want certain restrictions like:

• CEOs should only meet Investors

• Designers should only meet Product Managers

• Students should match only with Mentors

To enable this, we introduce matchmaking rules.

---

Database Tables Needed

To make this possible, there should be some tables in your system.

---

Groups Table

CREATE TABLE Groups (
    id INT PRIMARY KEY,
    name VARCHAR(50)
);

Each user can belong to one or more groups (CEO, Investor, Mentor, etc.).

---

Users Table

CREATE TABLE Users (
    id INT PRIMARY KEY,
    name VARCHAR(50)
);

---

User–Group Mapping Table

CREATE TABLE User_Groups (
    user_id INT PRIMARY KEY,
    group_id INT PRIMARY KEY,
    FOREIGN KEY (user_id) REFERENCES Users(id),
    FOREIGN KEY (group_id) REFERENCES Groups(id)
);

Since one user can belong to multiple groups,

---

Networking Table

CREATE TABLE Networking (
    id INT PRIMARY KEY,
    name VARCHAR(100)
);

---

Rules Table

CREATE TABLE Rules (
    id INT PRIMARY KEY,
    networking_id INT,
    from_group_id INT,
    to_group_id INT,
    FOREIGN KEY (networking_id) REFERENCES Networking(id),
    FOREIGN KEY (from_group_id) REFERENCES Groups(id),
    FOREIGN KEY (to_group_id) REFERENCES Groups(id)
);

from_group_id is the first group of the rule and to_group_id is second group of the rule.

---

Creating Matchmaking Rules

Now that we have these tables in our database, we can start creating matchmaking rules for a networking event.

The rule system is simple:

The organiser selects which groups are allowed to match with each other and the groups which are not included in the rule will get matched with each other.

---

Group-Based Rule Scenarios

Let’s consider the following groups:

A, B, C, D, E

And the organiser sets these rules:

• Group A → Group B

• Group B → Group C

• Group A → Group A

Based on these rules:

• Group A can match with A and B

• Group B can match with A and C

• Group C can match only with B

• Groups D and E, which are not part of any rule, will match only with each other

---

What Happens When a User Belongs to Multiple Groups?

Now imagine a user who is in both Group C and Group D.

How should matchmaking work for this user?

Since Group C has a rule allowing it to match only with Group B, the user’s allowed match groups will follow the strictest rule and it will be matched only with Group B users.

Even though the user also belongs to Group D, which normally matches with E, Group C’s rule takes priority because Group B → Group C defines a restricted matchmaking rule.