What’s the Buzz in Charlotte? A Pre-Conj Data Dive

Getting to know our host city for Clojure/conj 2025. We dive into 311 service data to see what’s on the minds of Charlotte’s citizens and get a taste of our hands-on data analysis workshop.
Author
Affiliation

Timothy Pratley

Hummi

Published

November 10, 2025

This November 12th, Clojure enthusiasts will gather in Charlotte, North Carolina for Clojure/conj 2025. It’s a cherished yearly conference of code, conversations, and that special “this is my people” feeling.

Note

Fun fact: during the Revolutionary War, a British general called Charlotte a “hornet’s nest of rebellion” for its fierce resistance. That same spirit of passionate engagement seems to live on in the city’s civic life today, on display using the hornet as their city emblem.

In the spirit of exploration, let’s get to know our host city before we arrive. What can 3 million service requests tell us about the heart of Charlotte?

Charlotte’s Data

Let’s find out by diving into the city’s 311 system; non-emergency service requests. Every pothole report, noise complaint, and fallen tree notification gets recorded.

Downloaded from Charlotte Service Requests.

(defonce Charlotte-311
  (tc/dataset (fs/file (fs/home) "Downloads" "Service_Requests_311.csv")
              {:key-fn csk/->kebab-case-keyword}))

Let’s see what columns we have

(tc/column-names Charlotte-311)
(:x
 :y
 :objectid
 :department
 :division
 :request-no
 :fiscal-year
 :fiscal-month
 :request-type
 :received-date
 :internal-field-observation
 :title
 :cmpd-division
 :neighborhood-profile-area
 :block-no
 :street-direction
 :street-name
 :street-type
 :city
 :state
 :zip-code
 :full-address
 :x-coord
 :y-coord
 :latitude
 :longitude
 :council-district
 :global-id
 :pid)

I wonder what the request types are

(tc/group-by Charlotte-311 :request-type)

_unnamed [175 3]:

:name :group-id :data
MISSED RECYCLING 0 Group: MISSED RECYCLING [56694 29]:
CDOT STREET SIGN REP/REPL 1 Group: CDOT STREET SIGN REP/REPL [14259 29]:
STREET SWEEPING/FLUSHING 2 Group: STREET SWEEPING/FLUSHING [10876 29]:
NON_RECYCLABLE ITEMS 3 Group: NON_RECYCLABLE ITEMS [1542623 29]:
HNS HEALTH AND SANITATION 4 Group: HNS HEALTH AND SANITATION [147023 29]:
CART REPAIR-GARBAGE 5 Group: CART REPAIR-GARBAGE [69893 29]:
RECYCLABLE ITEMS 6 Group: RECYCLABLE ITEMS [366433 29]:
SW DOCUMENT RECYCLING 7 Group: SW DOCUMENT RECYCLING [32594 29]:
PARKING ON LAWN OFFHOURS 8 Group: PARKING ON LAWN OFFHOURS [6019 29]:
CDOT SIGHT OBSTRUCTION 9 Group: CDOT SIGHT OBSTRUCTION [4055 29]:
… … …
NEW SVC BUSINESS GARBAGE 164 Group: NEW SVC BUSINESS GARBAGE [225 29]:
CURBIT PICKUP DAY INQUIRY 165 Group: CURBIT PICKUP DAY INQUIRY [39 29]:
ROW OBSTRUCT OTHER 166 Group: ROW OBSTRUCT OTHER [1630 29]:
SWS MLTFMLY SITE INVSTGT 167 Group: SWS MLTFMLY SITE INVSTGT [5 29]:
ILLEGAL PARKING 168 Group: ILLEGAL PARKING [1211 29]:
ZON DUPLEX/DUPLEXES 169 Group: ZON DUPLEX/DUPLEXES [68 29]:
SUBDIVISIONS 170 Group: SUBDIVISIONS [29 29]:
UT/WATER QUALITY TESTING 171 Group: UT/WATER QUALITY TESTING [1 29]:
CART PURCHASE 172 Group: CART PURCHASE [8 29]:
HOMELESS SUPPORT OUTREACH 173 Group: HOMELESS SUPPORT OUTREACH [929 29]:
HNS ESCALATED REQUESTS 174 Group: HNS ESCALATED REQUESTS [82 29]:

Let’s see what are the most common requests

(def frequent-requests
  (-> Charlotte-311
      (tc/group-by :request-type)
      (tc/aggregate {:frequency tc/row-count})
      (tc/order-by :frequency :desc)))
frequent-requests

_unnamed [175 2]:

:$group-name :frequency
NON_RECYCLABLE ITEMS 1542623
RECYCLABLE ITEMS 366433
HNS HEALTH AND SANITATION 147023
CART REPAIR-GARBAGE 69893
MISSED RECYCLING 56694
311 DOCUMENT 52972
SW DOCUMENT GARBAGE 46761
SW DOCUMENT RECYCLING 32594
DEAD ANIMAL COLLECTION 30048
SW DOCUMENT YARD WASTE 26465
… …
COVID 19-PRICE GOUGING 4
SW EXCESSIVE STORM-SW USE 2
SW REMINDER BULKY-SW USE 2
SWS MLTFMLY FIELD OBSERVE 2
ON CALL - SWS SPEC SERV 1
COMPLEX PROBLEM 1
UT/LANDSCAPE 1
DISABILITY ACT 1
UT/MANDATORY 1
BUS STOP-REMOVE TRASH CAN 1
UT/WATER QUALITY TESTING 1

The most frequent request type is about non-recyclable items. It suggests Charlotte residents care about recycling but might need clearer guidelines about what can be recycled. The high volume of requests also shows that people feel comfortable asking the city for guidance. Data like this helps cities improve their communication and services.

(-> frequent-requests
    (plotly/base {:=title "Charlotte 311 Service Requests"})
    (plotly/layer-bar {:=x-title "Request Type"
                       :=y :frequency
                       :=y-title "Count"}))

That’s a long tail you have there. Let’s focus on the top 5.

(-> frequent-requests
    (tc/select-rows (range 5))
    (plotly/base {:=title "Charlotte 311 Service Requests"})
    (plotly/layer-bar {:=x :$group-name
                       :=x-title "Request Type"
                       :=y :frequency
                       :=y-title "Count"}))

This brief analysis gives us a snapshot of daily life in Charlotte, revealing a community that’s actively engaged in civic life and recycling. It’s a perfect backdrop for the kind of thoughtful problem-solving we cherish in the Clojure community.

Clean data, clean streets. A city after our own hearts.

Clean data, clean streets. A city after our own hearts.

Join Us at the Workshop

This journey from a raw CSV file to a clear visualization is exactly what the Empowering Data Analysis through SciCloj workshop is all about. You’ll start your Conj experience by diving into practical, hands-on data analysis and come away with new ideas to carry back home.

You will learn how to:

  • Load and explore real-world datasets
  • Create clear, reproducible analyses
  • Share your insights through interactive notebooks
  • Leverage Clojure’s immutable data structures for data science

We can’t wait to explore data with you. See you in Charlotte!

source: src/conferences/conj2025/workshop/scicloj/buzz.clj