r/mainframe is a subreddit with 12k members. The community frequently discusses mainframe, cobol, z/os, career, and job.
Discussion of all things Mainframe - hardware & software, programming & support.
Popular Topics in r/mainframe
#1
Mainframe
218 posts
#2
Cobol
57 posts
#3
Z/os
42 posts
#4
Career
29 posts
#5
Job
27 posts
#6
Ibm
20 posts
#7
Learning
14 posts
#8
Jcl
13 posts
#9
Modernization
11 posts
#10
Migration
11 posts
Member Growth in r/mainframe
Yearly
+2k members(23.6%)
Similar Subreddits to r/mainframe
r/AskProgrammers
26k members
182.6% / yr
r/AskProgramming
237k members
21.8% / yr
r/cobol
9k members
23.8% / yr
r/cscareerquestions
2.4M members
5.2% / yr
r/csMajors
466k members
17.4% / yr
r/dataanalytics
49k members
63.5% / yr
r/developersIndia
1.6M members
12.5% / yr
r/Evaluation
1k members
16.7% / yr
r/programmer
36k members
89.5% / yr
r/supplychain
118k members
25.6% / yr
About
GummySearch helps people research Reddit communities by organizing activity, growth, themes, and post-level signals into one place.
This page gives a focused view of r/mainframe, including current member size, discussion patterns, product reviews, and related communities to explore.
This data is synced periodically so insights stay current and useful for ongoing research.
Last updated: October 26, 2026